JAVA-15787 Created new di-modules and server-modules

- Moved spring-freemarker to spring-web-modules
2022-11-24 20:19:58 +05:30
parent 4ea66b59ce
commit 7d3e1e13f5
156 changed files with 63 additions and 43 deletions
--- a/server-modules/apache-tomcat/pom.xml
+++ b/server-modules/apache-tomcat/pom.xml
@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>apache-tomcat</artifactId>
+    <name>apache-tomcat</name>
+    <packaging>pom</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>server-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <modules>
+        <module>sso</module>
+    </modules>
+
+    <build>
+        <defaultGoal>install</defaultGoal>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.codehaus.mojo</groupId>
+                    <artifactId>exec-maven-plugin</artifactId>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+</project>
--- a/server-modules/apache-tomcat/sso/.dockerignore
+++ b/server-modules/apache-tomcat/sso/.dockerignore
@@ -0,0 +1,24 @@
+**/.classpath
+**/.dockerignore
+**/.env
+**/.git
+**/.gitignore
+**/.project
+**/.settings
+**/.toolstarget
+**/.vs
+**/.vscode
+**/*.*proj.user
+**/*.dbmdl
+**/*.jfm
+**/bin
+**/charts
+**/docker-compose*
+**/compose*
+**/Dockerfile*
+**/node_modules
+**/npm-debug.log
+**/obj
+**/secrets.dev.yaml
+**/values.dev.yaml
+README.md
--- a/server-modules/apache-tomcat/sso/README.md
+++ b/server-modules/apache-tomcat/sso/README.md
@@ -0,0 +1,7 @@
+### Related articles
+
+- [SSO with Apache Tomcat](https://www.baeldung.com/apache-tomcat-sso)
+
+### Launch Example using Docker
+
+$ docker-compose up
--- a/server-modules/apache-tomcat/sso/docker-compose.yml
+++ b/server-modules/apache-tomcat/sso/docker-compose.yml
@@ -0,0 +1,11 @@
+version: '3.4'
+
+services:
+  tomcatsso:
+    image: tomcat:10-jdk17-openjdk-slim-buster
+    volumes:
+      - ./res/conf:/usr/local/tomcat/conf
+      - ./webapps:/usr/local/tomcat/webapps
+    ports:
+      - 8080:8080
+    command: ["catalina.sh", "run"]
--- a/server-modules/apache-tomcat/sso/pom.xml
+++ b/server-modules/apache-tomcat/sso/pom.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.baeldung.apache_tomcat</groupId>
+    <artifactId>sso</artifactId>
+    <version>1.0.0-SNAPSHOT</version>
+    <packaging>pom</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>apache-tomcat</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+</project>
--- a/server-modules/apache-tomcat/sso/res/conf/catalina.policy
+++ b/server-modules/apache-tomcat/sso/res/conf/catalina.policy
@@ -0,0 +1,264 @@
+// Licensed to the Apache Software Foundation (ASF) under one or more
+// contributor license agreements.  See the NOTICE file distributed with
+// this work for additional information regarding copyright ownership.
+// The ASF licenses this file to You under the Apache License, Version 2.0
+// (the "License"); you may not use this file except in compliance with
+// the License.  You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// ============================================================================
+// catalina.policy - Security Policy Permissions for Tomcat
+//
+// This file contains a default set of security policies to be enforced (by the
+// JVM) when Catalina is executed with the "-security" option.  In addition
+// to the permissions granted here, the following additional permissions are
+// granted to each web application:
+//
+// * Read access to the web application's document root directory
+// * Read, write and delete access to the web application's working directory
+// ============================================================================
+
+
+// ========== SYSTEM CODE PERMISSIONS =========================================
+
+
+// These permissions apply to javac
+grant codeBase "file:${java.home}/lib/-" {
+        permission java.security.AllPermission;
+};
+
+// These permissions apply to all shared system extensions
+grant codeBase "file:${java.home}/jre/lib/ext/-" {
+        permission java.security.AllPermission;
+};
+
+// These permissions apply to javac when ${java.home} points at $JAVA_HOME/jre
+grant codeBase "file:${java.home}/../lib/-" {
+        permission java.security.AllPermission;
+};
+
+// These permissions apply to all shared system extensions when
+// ${java.home} points at $JAVA_HOME/jre
+grant codeBase "file:${java.home}/lib/ext/-" {
+        permission java.security.AllPermission;
+};
+
+// This permission is required when using javac to compile JSPs on Java 9
+// onwards
+//grant codeBase "jrt:/jdk.compiler" {
+//        permission java.security.AllPermission;
+//};
+
+
+// ========== CATALINA CODE PERMISSIONS =======================================
+
+// These permissions apply to the daemon code
+grant codeBase "file:${catalina.home}/bin/commons-daemon.jar" {
+        permission java.security.AllPermission;
+};
+
+// These permissions apply to the logging API
+// Note: If tomcat-juli.jar is in ${catalina.base} and not in ${catalina.home},
+// update this section accordingly.
+//  grant codeBase "file:${catalina.base}/bin/tomcat-juli.jar" {..}
+grant codeBase "file:${catalina.home}/bin/tomcat-juli.jar" {
+        permission java.io.FilePermission
+         "${java.home}${file.separator}lib${file.separator}logging.properties", "read";
+
+        permission java.io.FilePermission
+         "${catalina.base}${file.separator}conf${file.separator}logging.properties", "read";
+        permission java.io.FilePermission
+         "${catalina.base}${file.separator}logs", "read, write";
+        permission java.io.FilePermission
+         "${catalina.base}${file.separator}logs${file.separator}*", "read, write, delete";
+
+        permission java.lang.RuntimePermission "shutdownHooks";
+        permission java.lang.RuntimePermission "getClassLoader";
+        permission java.lang.RuntimePermission "setContextClassLoader";
+
+        permission java.lang.management.ManagementPermission "monitor";
+
+        permission java.util.logging.LoggingPermission "control";
+
+        permission java.util.PropertyPermission "java.util.logging.config.class", "read";
+        permission java.util.PropertyPermission "java.util.logging.config.file", "read";
+        permission java.util.PropertyPermission "org.apache.juli.AsyncMaxRecordCount", "read";
+        permission java.util.PropertyPermission "org.apache.juli.AsyncOverflowDropType", "read";
+        permission java.util.PropertyPermission "org.apache.juli.ClassLoaderLogManager.debug", "read";
+        permission java.util.PropertyPermission "catalina.base", "read";
+
+        // Note: To enable per context logging configuration, permit read access to
+        // the appropriate file. Be sure that the logging configuration is
+        // secure before enabling such access.
+        // E.g. for the examples web application (uncomment and unwrap
+        // the following to be on a single line):
+        // permission java.io.FilePermission "${catalina.base}${file.separator}
+        //  webapps${file.separator}examples${file.separator}WEB-INF
+        //  ${file.separator}classes${file.separator}logging.properties", "read";
+};
+
+// These permissions apply to the server startup code
+grant codeBase "file:${catalina.home}/bin/bootstrap.jar" {
+        permission java.security.AllPermission;
+};
+
+// These permissions apply to the servlet API classes
+// and those that are shared across all class loaders
+// located in the "lib" directory
+grant codeBase "file:${catalina.home}/lib/-" {
+        permission java.security.AllPermission;
+};
+
+
+// If using a per instance lib directory, i.e. ${catalina.base}/lib,
+// then the following permission will need to be uncommented
+// grant codeBase "file:${catalina.base}/lib/-" {
+//         permission java.security.AllPermission;
+// };
+
+
+// ========== WEB APPLICATION PERMISSIONS =====================================
+
+
+// These permissions are granted by default to all web applications
+// In addition, a web application will be given a read FilePermission
+// for all files and directories in its document root.
+grant {
+    // Required for JNDI lookup of named JDBC DataSource's and
+    // javamail named MimePart DataSource used to send mail
+    permission java.util.PropertyPermission "java.home", "read";
+    permission java.util.PropertyPermission "java.naming.*", "read";
+    permission java.util.PropertyPermission "javax.sql.*", "read";
+
+    // OS Specific properties to allow read access
+    permission java.util.PropertyPermission "os.name", "read";
+    permission java.util.PropertyPermission "os.version", "read";
+    permission java.util.PropertyPermission "os.arch", "read";
+    permission java.util.PropertyPermission "file.separator", "read";
+    permission java.util.PropertyPermission "path.separator", "read";
+    permission java.util.PropertyPermission "line.separator", "read";
+
+    // JVM properties to allow read access
+    permission java.util.PropertyPermission "java.version", "read";
+    permission java.util.PropertyPermission "java.vendor", "read";
+    permission java.util.PropertyPermission "java.vendor.url", "read";
+    permission java.util.PropertyPermission "java.class.version", "read";
+    permission java.util.PropertyPermission "java.specification.version", "read";
+    permission java.util.PropertyPermission "java.specification.vendor", "read";
+    permission java.util.PropertyPermission "java.specification.name", "read";
+
+    permission java.util.PropertyPermission "java.vm.specification.version", "read";
+    permission java.util.PropertyPermission "java.vm.specification.vendor", "read";
+    permission java.util.PropertyPermission "java.vm.specification.name", "read";
+    permission java.util.PropertyPermission "java.vm.version", "read";
+    permission java.util.PropertyPermission "java.vm.vendor", "read";
+    permission java.util.PropertyPermission "java.vm.name", "read";
+
+    // Required for OpenJMX
+    permission java.lang.RuntimePermission "getAttribute";
+
+    // Allow read of JAXP compliant XML parser debug
+    permission java.util.PropertyPermission "jaxp.debug", "read";
+
+    // All JSPs need to be able to read this package
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.tomcat";
+
+    // Precompiled JSPs need access to these packages.
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.jasper.el";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.jasper.runtime";
+    permission java.lang.RuntimePermission
+     "accessClassInPackage.org.apache.jasper.runtime.*";
+
+    // Applications using WebSocket need to be able to access these packages
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.tomcat.websocket";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.tomcat.websocket.server";
+};
+
+
+// The Manager application needs access to the following packages to support the
+// session display functionality. It also requires the custom Tomcat
+// DeployXmlPermission to enable the use of META-INF/context.xml
+// These settings support the following configurations:
+// - default CATALINA_HOME == CATALINA_BASE
+// - CATALINA_HOME != CATALINA_BASE, per instance Manager in CATALINA_BASE
+// - CATALINA_HOME != CATALINA_BASE, shared Manager in CATALINA_HOME
+grant codeBase "file:${catalina.base}/webapps/manager/-" {
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.ha.session";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.manager";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.manager.util";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.util";
+    permission org.apache.catalina.security.DeployXmlPermission "manager";
+};
+grant codeBase "file:${catalina.home}/webapps/manager/-" {
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.ha.session";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.manager";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.manager.util";
+    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.util";
+    permission org.apache.catalina.security.DeployXmlPermission "manager";
+};
+
+// The Host Manager application needs the custom Tomcat DeployXmlPermission to
+// enable the use of META-INF/context.xml
+// These settings support the following configurations:
+// - default CATALINA_HOME == CATALINA_BASE
+// - CATALINA_HOME != CATALINA_BASE, per instance Host Manager in CATALINA_BASE
+// - CATALINA_HOME != CATALINA_BASE, shared Host Manager in CATALINA_HOME
+grant codeBase "file:${catalina.base}/webapps/host-manager/-" {
+    permission org.apache.catalina.security.DeployXmlPermission "host-manager";
+};
+grant codeBase "file:${catalina.home}/webapps/host-manager/-" {
+    permission org.apache.catalina.security.DeployXmlPermission "host-manager";
+};
+
+
+// You can assign additional permissions to particular web applications by
+// adding additional "grant" entries here, based on the code base for that
+// application, /WEB-INF/classes/, or /WEB-INF/lib/ jar files.
+//
+// Different permissions can be granted to JSP pages, classes loaded from
+// the /WEB-INF/classes/ directory, all jar files in the /WEB-INF/lib/
+// directory, or even to individual jar files in the /WEB-INF/lib/ directory.
+//
+// For instance, assume that the standard "examples" application
+// included a JDBC driver that needed to establish a network connection to the
+// corresponding database and used the scrape taglib to get the weather from
+// the NOAA web server.  You might create a "grant" entries like this:
+//
+// The permissions granted to the context root directory apply to JSP pages.
+// grant codeBase "file:${catalina.base}/webapps/examples/-" {
+//      permission java.net.SocketPermission "dbhost.mycompany.com:5432", "connect";
+//      permission java.net.SocketPermission "*.noaa.gov:80", "connect";
+// };
+//
+// The permissions granted to the context WEB-INF/classes directory
+// grant codeBase "file:${catalina.base}/webapps/examples/WEB-INF/classes/-" {
+// };
+//
+// The permission granted to your JDBC driver
+// grant codeBase "jar:file:${catalina.base}/webapps/examples/WEB-INF/lib/driver.jar!/-" {
+//      permission java.net.SocketPermission "dbhost.mycompany.com:5432", "connect";
+// };
+// The permission granted to the scrape taglib
+// grant codeBase "jar:file:${catalina.base}/webapps/examples/WEB-INF/lib/scrape.jar!/-" {
+//      permission java.net.SocketPermission "*.noaa.gov:80", "connect";
+// };
+
+// To grant permissions for web applications using packed WAR files, use the
+// Tomcat specific WAR url scheme.
+//
+// The permissions granted to the entire web application
+// grant codeBase "war:file:${catalina.base}/webapps/examples.war*/-" {
+// };
+//
+// The permissions granted to a specific JAR
+// grant codeBase "war:file:${catalina.base}/webapps/examples.war*/WEB-INF/lib/foo.jar" {
+// };
--- a/server-modules/apache-tomcat/sso/res/conf/catalina.properties
+++ b/server-modules/apache-tomcat/sso/res/conf/catalina.properties
@@ -0,0 +1,208 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#
+# List of comma-separated packages that start with or equal this string
+# will cause a security exception to be thrown when
+# passed to checkPackageAccess unless the
+# corresponding RuntimePermission ("accessClassInPackage."+package) has
+# been granted.
+package.access=sun.,org.apache.catalina.,org.apache.coyote.,org.apache.jasper.,org.apache.tomcat.
+#
+# List of comma-separated packages that start with or equal this string
+# will cause a security exception to be thrown when
+# passed to checkPackageDefinition unless the
+# corresponding RuntimePermission ("defineClassInPackage."+package) has
+# been granted.
+#
+# by default, no packages are restricted for definition, and none of
+# the class loaders supplied with the JDK call checkPackageDefinition.
+#
+package.definition=sun.,java.,org.apache.catalina.,org.apache.coyote.,\
+org.apache.jasper.,org.apache.naming.,org.apache.tomcat.
+
+#
+#
+# List of comma-separated paths defining the contents of the "common"
+# classloader. Prefixes should be used to define what is the repository type.
+# Path may be relative to the CATALINA_HOME or CATALINA_BASE path or absolute.
+# If left as blank,the JVM system loader will be used as Catalina's "common"
+# loader.
+# Examples:
+#     "foo": Add this folder as a class repository
+#     "foo/*.jar": Add all the JARs of the specified folder as class
+#                  repositories
+#     "foo/bar.jar": Add bar.jar as a class repository
+#
+# Note: Values are enclosed in double quotes ("...") in case either the
+#       ${catalina.base} path or the ${catalina.home} path contains a comma.
+#       Because double quotes are used for quoting, the double quote character
+#       may not appear in a path.
+common.loader="${catalina.base}/lib","${catalina.base}/lib/*.jar","${catalina.home}/lib","${catalina.home}/lib/*.jar"
+
+#
+# List of comma-separated paths defining the contents of the "server"
+# classloader. Prefixes should be used to define what is the repository type.
+# Path may be relative to the CATALINA_HOME or CATALINA_BASE path or absolute.
+# If left as blank, the "common" loader will be used as Catalina's "server"
+# loader.
+# Examples:
+#     "foo": Add this folder as a class repository
+#     "foo/*.jar": Add all the JARs of the specified folder as class
+#                  repositories
+#     "foo/bar.jar": Add bar.jar as a class repository
+#
+# Note: Values may be enclosed in double quotes ("...") in case either the
+#       ${catalina.base} path or the ${catalina.home} path contains a comma.
+#       Because double quotes are used for quoting, the double quote character
+#       may not appear in a path.
+server.loader=
+
+#
+# List of comma-separated paths defining the contents of the "shared"
+# classloader. Prefixes should be used to define what is the repository type.
+# Path may be relative to the CATALINA_BASE path or absolute. If left as blank,
+# the "common" loader will be used as Catalina's "shared" loader.
+# Examples:
+#     "foo": Add this folder as a class repository
+#     "foo/*.jar": Add all the JARs of the specified folder as class
+#                  repositories
+#     "foo/bar.jar": Add bar.jar as a class repository
+# Please note that for single jars, e.g. bar.jar, you need the URL form
+# starting with file:.
+#
+# Note: Values may be enclosed in double quotes ("...") in case either the
+#       ${catalina.base} path or the ${catalina.home} path contains a comma.
+#       Because double quotes are used for quoting, the double quote character
+#       may not appear in a path.
+shared.loader=
+
+# Default list of JAR files that should not be scanned using the JarScanner
+# functionality. This is typically used to scan JARs for configuration
+# information. JARs that do not contain such information may be excluded from
+# the scan to speed up the scanning process. This is the default list. JARs on
+# this list are excluded from all scans. The list must be a comma separated list
+# of JAR file names.
+# The list of JARs to skip may be over-ridden at a Context level for individual
+# scan types by configuring a JarScanner with a nested JarScanFilter.
+# The JARs listed below include:
+# - Tomcat Bootstrap JARs
+# - Tomcat API JARs
+# - Catalina JARs
+# - Jasper JARs
+# - Tomcat JARs
+# - Common non-Tomcat JARs
+# - Test JARs (JUnit, Cobertura and dependencies)
+tomcat.util.scan.StandardJarScanFilter.jarsToSkip=\
+annotations-api.jar,\
+ant-junit*.jar,\
+ant-launcher.jar,\
+ant.jar,\
+asm-*.jar,\
+aspectj*.jar,\
+bootstrap.jar,\
+catalina-ant.jar,\
+catalina-ha.jar,\
+catalina-ssi.jar,\
+catalina-storeconfig.jar,\
+catalina-tribes.jar,\
+catalina.jar,\
+cglib-*.jar,\
+cobertura-*.jar,\
+commons-beanutils*.jar,\
+commons-codec*.jar,\
+commons-collections*.jar,\
+commons-daemon.jar,\
+commons-dbcp*.jar,\
+commons-digester*.jar,\
+commons-fileupload*.jar,\
+commons-httpclient*.jar,\
+commons-io*.jar,\
+commons-lang*.jar,\
+commons-logging*.jar,\
+commons-math*.jar,\
+commons-pool*.jar,\
+derby-*.jar,\
+dom4j-*.jar,\
+easymock-*.jar,\
+ecj-*.jar,\
+el-api.jar,\
+geronimo-spec-jaxrpc*.jar,\
+h2*.jar,\
+hamcrest-*.jar,\
+hibernate*.jar,\
+httpclient*.jar,\
+icu4j-*.jar,\
+jakartaee-migration-*.jar,\
+jasper-el.jar,\
+jasper.jar,\
+jaspic-api.jar,\
+jaxb-*.jar,\
+jaxen-*.jar,\
+jdom-*.jar,\
+jetty-*.jar,\
+jmx-tools.jar,\
+jmx.jar,\
+jsp-api.jar,\
+jstl.jar,\
+jta*.jar,\
+junit-*.jar,\
+junit.jar,\
+log4j*.jar,\
+mail*.jar,\
+objenesis-*.jar,\
+oraclepki.jar,\
+oro-*.jar,\
+servlet-api-*.jar,\
+servlet-api.jar,\
+slf4j*.jar,\
+taglibs-standard-spec-*.jar,\
+tagsoup-*.jar,\
+tomcat-api.jar,\
+tomcat-coyote.jar,\
+tomcat-dbcp.jar,\
+tomcat-i18n-*.jar,\
+tomcat-jdbc.jar,\
+tomcat-jni.jar,\
+tomcat-juli-adapters.jar,\
+tomcat-juli.jar,\
+tomcat-util-scan.jar,\
+tomcat-util.jar,\
+tomcat-websocket.jar,\
+tools.jar,\
+websocket-api.jar,\
+wsdl4j*.jar,\
+xercesImpl.jar,\
+xml-apis.jar,\
+xmlParserAPIs-*.jar,\
+xmlParserAPIs.jar,\
+xom-*.jar
+
+# Default list of JAR files that should be scanned that overrides the default
+# jarsToSkip list above. This is typically used to include a specific JAR that
+# has been excluded by a broad file name pattern in the jarsToSkip list.
+# The list of JARs to scan may be over-ridden at a Context level for individual
+# scan types by configuring a JarScanner with a nested JarScanFilter.
+tomcat.util.scan.StandardJarScanFilter.jarsToScan=\
+log4j-taglib*.jar,\
+log4j-web*.jar,\
+log4javascript*.jar,\
+slf4j-taglib*.jar
+
+# String cache configuration.
+tomcat.util.buf.StringCache.byte.enabled=true
+#tomcat.util.buf.StringCache.char.enabled=true
+#tomcat.util.buf.StringCache.trainThreshold=500000
+#tomcat.util.buf.StringCache.cacheSize=5000
--- a/server-modules/apache-tomcat/sso/res/conf/context.xml
+++ b/server-modules/apache-tomcat/sso/res/conf/context.xml
@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<!-- The contents of this file will be loaded for each web application -->
+<Context>
+
+    <!-- Default set of monitored resources. If one of these changes, the    -->
+    <!-- web application will be reloaded.                                   -->
+    <WatchedResource>WEB-INF/web.xml</WatchedResource>
+    <WatchedResource>WEB-INF/tomcat-web.xml</WatchedResource>
+    <WatchedResource>${catalina.base}/conf/web.xml</WatchedResource>
+
+    <!-- Uncomment this to enable session persistence across Tomcat restarts -->
+    <!--
+    <Manager pathname="SESSIONS.ser" />
+    -->
+</Context>
--- a/server-modules/apache-tomcat/sso/res/conf/jaspic-providers.xml
+++ b/server-modules/apache-tomcat/sso/res/conf/jaspic-providers.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<jaspic-providers xmlns="http://tomcat.apache.org/xml"
+                  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+                  xsi:schemaLocation="http://tomcat.apache.org/xml jaspic-providers.xsd"
+                  version="1.0">
+  <!-- No JASPIC providers configured by default -->
+</jaspic-providers>
--- a/server-modules/apache-tomcat/sso/res/conf/jaspic-providers.xsd
+++ b/server-modules/apache-tomcat/sso/res/conf/jaspic-providers.xsd
@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<xs:schema xmlns="http://www.w3.org/2001/XMLSchema"
+           targetNamespace="http://tomcat.apache.org/xml"
+           xmlns:jaspic="http://tomcat.apache.org/xml"
+           xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified"
+           version="1.0">
+  <xs:element name="jaspic-providers">
+    <xs:complexType>
+      <xs:sequence>
+        <xs:element name="provider" minOccurs="0" maxOccurs="unbounded">
+          <xs:complexType>
+            <xs:sequence>
+              <xs:element name="property" minOccurs="0" maxOccurs="unbounded">
+                <xs:complexType>
+                  <xs:attribute name="name" use="required" type="jaspic:propertyname" />
+                  <xs:attribute name="value" use="required" type="xs:string" />
+                </xs:complexType>
+              </xs:element>
+            </xs:sequence>
+            <xs:attribute name="className" type="xs:string" />
+            <xs:attribute name="layer" type="xs:string" />
+            <xs:attribute name="appContext" type="xs:string" />
+            <xs:attribute name="description" type="xs:string" />
+          </xs:complexType>
+        </xs:element>
+      </xs:sequence>
+      <xs:attribute name="version" type="xs:string" />
+    </xs:complexType>
+  </xs:element>
+  <xs:simpleType name="propertyname">
+    <xs:restriction base="xs:string">
+      <xs:minLength value="1"/>
+    </xs:restriction>
+  </xs:simpleType>
+</xs:schema>
--- a/server-modules/apache-tomcat/sso/res/conf/logging.properties
+++ b/server-modules/apache-tomcat/sso/res/conf/logging.properties
@@ -0,0 +1,90 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+handlers = 1catalina.org.apache.juli.AsyncFileHandler, 2localhost.org.apache.juli.AsyncFileHandler, 3manager.org.apache.juli.AsyncFileHandler, 4host-manager.org.apache.juli.AsyncFileHandler, java.util.logging.ConsoleHandler
+
+.handlers = 1catalina.org.apache.juli.AsyncFileHandler, java.util.logging.ConsoleHandler
+
+############################################################
+# Handler specific properties.
+# Describes specific configuration info for Handlers.
+############################################################
+
+1catalina.org.apache.juli.AsyncFileHandler.level = ALL
+1catalina.org.apache.juli.AsyncFileHandler.directory = ${catalina.base}/logs
+1catalina.org.apache.juli.AsyncFileHandler.prefix = catalina.
+1catalina.org.apache.juli.AsyncFileHandler.maxDays = 90
+1catalina.org.apache.juli.AsyncFileHandler.encoding = UTF-8
+
+2localhost.org.apache.juli.AsyncFileHandler.level = FINE
+2localhost.org.apache.juli.AsyncFileHandler.directory = ${catalina.base}/logs
+2localhost.org.apache.juli.AsyncFileHandler.prefix = localhost.
+2localhost.org.apache.juli.AsyncFileHandler.maxDays = 90
+2localhost.org.apache.juli.AsyncFileHandler.encoding = UTF-8
+
+3manager.org.apache.juli.AsyncFileHandler.level = FINE
+3manager.org.apache.juli.AsyncFileHandler.directory = ${catalina.base}/logs
+3manager.org.apache.juli.AsyncFileHandler.prefix = manager.
+3manager.org.apache.juli.AsyncFileHandler.maxDays = 90
+3manager.org.apache.juli.AsyncFileHandler.encoding = UTF-8
+
+4host-manager.org.apache.juli.AsyncFileHandler.level = FINE
+4host-manager.org.apache.juli.AsyncFileHandler.directory = ${catalina.base}/logs
+4host-manager.org.apache.juli.AsyncFileHandler.prefix = host-manager.
+4host-manager.org.apache.juli.AsyncFileHandler.maxDays = 90
+4host-manager.org.apache.juli.AsyncFileHandler.encoding = UTF-8
+
+java.util.logging.ConsoleHandler.level = FINE
+java.util.logging.ConsoleHandler.formatter = org.apache.juli.OneLineFormatter
+java.util.logging.ConsoleHandler.encoding = UTF-8
+
+org.apache.catalina.authenticator.level = FINE
+org.apache.catalina.authenticator.formatter = org.apache.juli.OneLineFormatter
+org.apache.catalina.authenticator.encoding = UTF-8
+
+org.apache.catalina.Realm.level = FINE
+org.apache.catalina.Realm.formatter = org.apache.juli.OneLineFormatter
+org.apache.catalina.Realm.encoding = UTF-8
+
+org.apache.catalina.realm.level = FINE
+org.apache.catalina.realm.formatter = org.apache.juli.OneLineFormatter
+org.apache.catalina.realm.encoding = UTF-8
+
+############################################################
+# Facility specific properties.
+# Provides extra control for each logger.
+############################################################
+
+org.apache.catalina.core.ContainerBase.[Catalina].[localhost].level = ALL
+org.apache.catalina.core.ContainerBase.[Catalina].[localhost].handlers = 2localhost.org.apache.juli.AsyncFileHandler
+
+org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager].level = INFO
+org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager].handlers = 3manager.org.apache.juli.AsyncFileHandler
+
+org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager].level = INFO
+org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager].handlers = 4host-manager.org.apache.juli.AsyncFileHandler
+
+# For example, set the org.apache.catalina.util.LifecycleBase logger to log
+# each component that extends LifecycleBase changing state:
+# org.apache.catalina.util.LifecycleBase.level = FINE
+
+# To see debug messages in TldLocationsCache, uncomment the following line:
+#org.apache.jasper.compiler.TldLocationsCache.level = FINE
+
+# To see debug messages for HTTP/2 handling, uncomment the following line:
+#org.apache.coyote.http2.level = FINE
+
+# To see debug messages for WebSocket handling, uncomment the following line:
+#org.apache.tomcat.websocket.level = FINE
--- a/server-modules/apache-tomcat/sso/res/conf/server.xml
+++ b/server-modules/apache-tomcat/sso/res/conf/server.xml
@@ -0,0 +1,151 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<!-- Note:  A "Server" is not itself a "Container", so you may not
+     define subcomponents such as "Valves" at this level.
+     Documentation at /docs/config/server.html
+ -->
+<Server port="8005" shutdown="SHUTDOWN">
+  <Listener className="org.apache.catalina.startup.VersionLoggerListener" />
+  <!-- Security listener. Documentation at /docs/config/listeners.html
+  <Listener className="org.apache.catalina.security.SecurityListener" />
+  -->
+  <!-- APR library loader. Documentation at /docs/apr.html -->
+  <Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
+  <!-- Prevent memory leaks due to use of particular java/javax APIs-->
+  <Listener className="org.apache.catalina.core.JreMemoryLeakPreventionListener" />
+  <Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
+  <Listener className="org.apache.catalina.core.ThreadLocalLeakPreventionListener" />
+
+  <!-- Global JNDI resources
+       Documentation at /docs/jndi-resources-howto.html
+  -->
+  <GlobalNamingResources>
+    <!-- Editable user database that can also be used by
+         UserDatabaseRealm to authenticate users
+    -->
+    <Resource name="UserDatabase" auth="Container"
+              type="org.apache.catalina.UserDatabase"
+              description="User database that can be updated and saved"
+              factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
+              pathname="conf/tomcat-users.xml" />
+  </GlobalNamingResources>
+
+  <!-- A "Service" is a collection of one or more "Connectors" that share
+       a single "Container" Note:  A "Service" is not itself a "Container",
+       so you may not define subcomponents such as "Valves" at this level.
+       Documentation at /docs/config/service.html
+   -->
+  <Service name="Catalina">
+
+    <!--The connectors can use a shared executor, you can define one or more named thread pools-->
+    <!--
+    <Executor name="tomcatThreadPool" namePrefix="catalina-exec-"
+        maxThreads="150" minSpareThreads="4"/>
+    -->
+
+
+    <!-- A "Connector" represents an endpoint by which requests are received
+         and responses are returned. Documentation at :
+         HTTP Connector: /docs/config/http.html
+         AJP  Connector: /docs/config/ajp.html
+         Define a non-SSL/TLS HTTP/1.1 Connector on port 8080
+    -->
+    <Connector port="8080" protocol="HTTP/1.1"
+               connectionTimeout="20000"
+               redirectPort="8443" />
+    <!-- A "Connector" using the shared thread pool-->
+    <!--
+    <Connector executor="tomcatThreadPool"
+               port="8080" protocol="HTTP/1.1"
+               connectionTimeout="20000"
+               redirectPort="8443" />
+    -->
+    <!-- Define an SSL/TLS HTTP/1.1 Connector on port 8443 with HTTP/2
+         This connector uses the NIO implementation. The default
+         SSLImplementation will depend on the presence of the APR/native
+         library and the useOpenSSL attribute of the AprLifecycleListener.
+         Either JSSE or OpenSSL style configuration may be used regardless of
+         the SSLImplementation selected. JSSE style configuration is used below.
+    -->
+    <!--
+    <Connector port="8443" protocol="org.apache.coyote.http11.Http11NioProtocol"
+               maxThreads="150" SSLEnabled="true">
+        <UpgradeProtocol className="org.apache.coyote.http2.Http2Protocol" />
+        <SSLHostConfig>
+            <Certificate certificateKeystoreFile="conf/localhost-rsa.jks"
+                         type="RSA" />
+        </SSLHostConfig>
+    </Connector>
+    -->
+
+    <!-- Define an AJP 1.3 Connector on port 8009 -->
+    <!--
+    <Connector protocol="AJP/1.3"
+               address="::1"
+               port="8009"
+               redirectPort="8443" />
+    -->
+
+    <!-- An Engine represents the entry point (within Catalina) that processes
+         every request.  The Engine implementation for Tomcat stand alone
+         analyzes the HTTP headers included with the request, and passes them
+         on to the appropriate Host (virtual host).
+         Documentation at /docs/config/engine.html -->
+
+    <!-- You should set jvmRoute to support load-balancing via AJP ie :
+    <Engine name="Catalina" defaultHost="localhost" jvmRoute="jvm1">
+    -->
+    <Engine name="Catalina" defaultHost="localhost">
+
+      <!--For clustering, please take a look at documentation at:
+          /docs/cluster-howto.html  (simple how to)
+          /docs/config/cluster.html (reference documentation) -->
+      <!--
+      <Cluster className="org.apache.catalina.ha.tcp.SimpleTcpCluster"/>
+      -->
+
+      <!-- Use the LockOutRealm to prevent attempts to guess user passwords
+           via a brute-force attack -->
+      <Realm className="org.apache.catalina.realm.LockOutRealm">
+        <!-- This Realm uses the UserDatabase configured in the global JNDI
+             resources under the key "UserDatabase".  Any edits
+             that are performed against this UserDatabase are immediately
+             available for use by the Realm.  -->
+        <Realm className="org.apache.catalina.realm.UserDatabaseRealm"
+               resourceName="UserDatabase"/>
+      </Realm>
+
+      <Host name="localhost"  appBase="webapps"
+            unpackWARs="true" autoDeploy="true">
+
+        <!-- SingleSignOn valve, share authentication between web applications
+             Documentation at: /docs/config/valve.html -->
+        <Valve className="org.apache.catalina.authenticator.SingleSignOn" />
+        
+
+        <!-- Access log processes all example.
+             Documentation at: /docs/config/valve.html
+             Note: The pattern used is equivalent to using pattern="common" -->
+        <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
+               prefix="localhost_access_log" suffix=".txt"
+               pattern="%h %l %u %t &quot;%r&quot; %s %b" />
+
+      </Host>
+    </Engine>
+  </Service>
+</Server>
--- a/server-modules/apache-tomcat/sso/res/conf/tomcat-users.xml
+++ b/server-modules/apache-tomcat/sso/res/conf/tomcat-users.xml
@@ -0,0 +1,59 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<tomcat-users xmlns="http://tomcat.apache.org/xml"
+              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+              xsi:schemaLocation="http://tomcat.apache.org/xml tomcat-users.xsd"
+              version="1.0">
+<!--
+  By default, no user is included in the "manager-gui" role required
+  to operate the "/manager/html" web application.  If you wish to use this app,
+  you must define such a user - the username and password are arbitrary.
+
+  Built-in Tomcat manager roles:
+    - manager-gui    - allows access to the HTML GUI and the status pages
+    - manager-script - allows access to the HTTP API and the status pages
+    - manager-jmx    - allows access to the JMX proxy and the status pages
+    - manager-status - allows access to the status pages only
+
+  The users below are wrapped in a comment and are therefore ignored. If you
+  wish to configure one or more of these users for use with the manager web
+  application, do not forget to remove the <!.. ..> that surrounds them. You
+  will also need to set the passwords to something appropriate.
+-->
+<!--
+  <user username="admin" password="<must-be-changed>" roles="manager-gui"/>
+  <user username="robot" password="<must-be-changed>" roles="manager-script"/>
+-->
+<!--
+  The sample user and role entries below are intended for use with the
+  examples web application. They are wrapped in a comment and thus are ignored
+  when reading this file. If you wish to configure these users for use with the
+  examples web application, do not forget to remove the <!.. ..> that surrounds
+  them. You will also need to set the passwords to something appropriate.
+-->
+<!--
+  <role rolename="tomcat"/>
+  <role rolename="role1"/>
+  <user username="tomcat" password="<must-be-changed>" roles="tomcat"/>
+  <user username="both" password="<must-be-changed>" roles="tomcat,role1"/>
+  <user username="role1" password="<must-be-changed>" roles="role1"/>
+-->
+  <role rolename="admin"/>
+  <user username="demo" password="demo" roles="admin"/>
+
+</tomcat-users>
--- a/server-modules/apache-tomcat/sso/res/conf/tomcat-users.xsd
+++ b/server-modules/apache-tomcat/sso/res/conf/tomcat-users.xsd
@@ -0,0 +1,59 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<xs:schema xmlns="http://www.w3.org/2001/XMLSchema"
+           targetNamespace="http://tomcat.apache.org/xml"
+           xmlns:users="http://tomcat.apache.org/xml"
+           xmlns:xs="http://www.w3.org/2001/XMLSchema"
+           elementFormDefault="qualified"
+           attributeFormDefault="unqualified"
+           version="1.0">
+  <xs:element name="tomcat-users">
+    <xs:complexType>
+      <xs:choice minOccurs="0" maxOccurs="unbounded">
+        <xs:element name="role">
+          <xs:complexType>
+            <xs:attribute name="rolename" use="required" type="users:entityname" />
+            <xs:attribute name="description" type="xs:string" />
+          </xs:complexType>
+        </xs:element>
+        <xs:element name="group">
+          <xs:complexType>
+            <xs:attribute name="groupname" use="required" type="users:entityname" />
+            <xs:attribute name="description" type="xs:string" />
+            <xs:attribute name="roles" type="xs:string" />
+          </xs:complexType>
+        </xs:element>
+        <xs:element name="user">
+          <xs:complexType>
+            <xs:attribute name="username" use="required" type="users:entityname" />
+            <xs:attribute name="fullname" type="xs:string" />
+            <xs:attribute name="password" type="xs:string" />
+            <xs:attribute name="roles" type="xs:string" />
+            <xs:attribute name="groups" type="xs:string" />
+          </xs:complexType>
+        </xs:element>
+      </xs:choice>
+      <xs:attribute name="version" type="xs:string" />
+    </xs:complexType>
+  </xs:element>
+  <xs:simpleType name="entityname">
+    <xs:restriction base="xs:string">
+      <xs:minLength value="1"/>
+    </xs:restriction>
+  </xs:simpleType>
+</xs:schema>
--- a/server-modules/apache-tomcat/sso/res/conf/web.xml
+++ b/server-modules/apache-tomcat/sso/res/conf/web.xml
--- a/server-modules/apache-tomcat/sso/webapps/ping/WEB-INF/web.xml
+++ b/server-modules/apache-tomcat/sso/webapps/ping/WEB-INF/web.xml
@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<web-app
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xmlns="http://java.sun.com/xml/ns/javaee"
+  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_4_0.xsd"
+  id="ping"
+  version="3.0">
+    <display-name>Ping</display-name>
+
+    <security-constraint>
+        <display-name>Ping Login Auth</display-name>
+        <web-resource-collection>
+            <web-resource-name>PingRestrictedAccess</web-resource-name>
+            <url-pattern>/private/*</url-pattern>     
+        </web-resource-collection>
+        <auth-constraint>
+            <role-name>admin</role-name>        
+        </auth-constraint>
+        <user-data-constraint>
+            <transport-guarantee>NONE</transport-guarantee>     
+        </user-data-constraint>
+    </security-constraint>
+
+    <security-role>
+        <role-name>admin</role-name>
+    </security-role>
+
+    <login-config>
+        <auth-method>FORM</auth-method>
+        <form-login-config>
+            <form-login-page>/logging.html</form-login-page>
+            <form-error-page>/logging_error.html</form-error-page>       
+        </form-login-config>
+    </login-config>
+
+    <filter>
+        <filter-name>PingExpiresFilter</filter-name>
+        <filter-class>org.apache.catalina.filters.ExpiresFilter</filter-class>
+        <init-param>
+            <param-name>ExpiresByType text/html</param-name>
+            <param-value>access plus 0 seconds</param-value>
+        </init-param>
+    </filter>
+
+    <filter-mapping>
+        <filter-name>PingExpiresFilter</filter-name>
+        <url-pattern>/private/*</url-pattern>
+        <dispatcher>REQUEST</dispatcher>
+    </filter-mapping>
+</web-app>
--- a/server-modules/apache-tomcat/sso/webapps/ping/index.html
+++ b/server-modules/apache-tomcat/sso/webapps/ping/index.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Ping</title>
+</head>
+<body>
+    <a href="private/index.html">Start pinging</a>    
+</body>
+</html>
--- a/server-modules/apache-tomcat/sso/webapps/ping/logging.html
+++ b/server-modules/apache-tomcat/sso/webapps/ping/logging.html
@@ -0,0 +1,26 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Ping - Login</title>
+</head>
+<body>
+    <form method="post" action="j_security_check">
+        <table >
+            <tr>
+                <td>User name: </td>
+                <td><input type="text" name="j_username" 
+                           size="20"/></td>
+            </tr>
+            <tr>
+                <td>Password: </td>
+                <td><input type="password" name="j_password" 
+                           size="20"/></td>
+            </tr>
+        </table>
+        <p></p>
+        <input type="submit" value="Submit"/>
+        &nbsp;
+        <input type="reset" value="Reset"/>
+    </form>
+</body>
+</html>
--- a/server-modules/apache-tomcat/sso/webapps/ping/logging_error.html
+++ b/server-modules/apache-tomcat/sso/webapps/ping/logging_error.html
@@ -0,0 +1,10 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Ping</title>
+</head>
+<body>
+    Error logging in!
+    <a href="index.html">Try again</a>
+</body>
+</html>
--- a/server-modules/apache-tomcat/sso/webapps/ping/private/index.html
+++ b/server-modules/apache-tomcat/sso/webapps/ping/private/index.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Ping - Pinging</title>
+</head>
+<body>
+    <a href="/pong/private/index.html">Pong!</a>
+</body>
+</html>
--- a/server-modules/apache-tomcat/sso/webapps/pong/WEB-INF/web.xml
+++ b/server-modules/apache-tomcat/sso/webapps/pong/WEB-INF/web.xml
@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
+  <display-name>Pong</display-name>
+  <welcome-file-list>
+    <welcome-file>index.html</welcome-file>
+  </welcome-file-list>
+
+
+    <security-constraint>
+        <display-name>Pong Login Auth</display-name>
+        <web-resource-collection>
+            <web-resource-name>PongRestrictedAccess</web-resource-name>
+            <url-pattern>/private/*</url-pattern>     
+        </web-resource-collection>
+        <auth-constraint>
+            <role-name>admin</role-name>        
+        </auth-constraint>
+        <user-data-constraint>
+            <transport-guarantee>NONE</transport-guarantee>     
+        </user-data-constraint>
+    </security-constraint>
+
+    <security-role>
+        <role-name>admin</role-name>
+    </security-role>
+
+
+    <login-config>
+        <auth-method>DIGEST</auth-method>
+    </login-config>
+
+    <filter>
+        <filter-name>PongExpiresFilter</filter-name>
+        <filter-class>org.apache.catalina.filters.ExpiresFilter</filter-class>
+        <init-param>
+            <param-name>ExpiresByType text/html</param-name>
+            <param-value>access plus 0 seconds</param-value>
+        </init-param>
+    </filter>
+
+    <filter-mapping>
+        <filter-name>PongExpiresFilter</filter-name>
+        <url-pattern>/private/*</url-pattern>
+        <dispatcher>REQUEST</dispatcher>
+    </filter-mapping>
+
+</web-app>
--- a/server-modules/apache-tomcat/sso/webapps/pong/index.html
+++ b/server-modules/apache-tomcat/sso/webapps/pong/index.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Pong</title>
+</head>
+<body>
+    <a href="private/index.html">Start ponging</a>    
+</body>
+</html>
--- a/server-modules/apache-tomcat/sso/webapps/pong/private/index.html
+++ b/server-modules/apache-tomcat/sso/webapps/pong/private/index.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Pong - Ponging</title>
+</head>
+<body>
+    <a href="/ping/private/index.html">Ping!</a>
+</body>
+</html>
--- a/server-modules/netty/README.md
+++ b/server-modules/netty/README.md
@@ -0,0 +1,4 @@
+### Relevant Articles:
+
+- [HTTP/2 in Netty](https://www.baeldung.com/netty-http2)
+- [HTTP Server with Netty](https://www.baeldung.com/java-netty-http-server)
--- a/server-modules/netty/pom.xml
+++ b/server-modules/netty/pom.xml
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>netty</artifactId>
+    <name>netty</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>server-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.netty</groupId>
+            <artifactId>netty-all</artifactId>
+            <version>${netty.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.conscrypt</groupId>
+            <artifactId>conscrypt-openjdk-uber</artifactId>
+            <version>${conscrypt-openjdk-uber.version}</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <netty.version>4.1.48.Final</netty.version>
+        <conscrypt-openjdk-uber.version>2.4.0</conscrypt-openjdk-uber.version>
+    </properties>
+
+</project>
--- a/server-modules/netty/src/main/java/com/baeldung/http/server/CustomHttpServerHandler.java
+++ b/server-modules/netty/src/main/java/com/baeldung/http/server/CustomHttpServerHandler.java
@@ -0,0 +1,97 @@
+package com.baeldung.http.server;
+
+import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
+import static io.netty.handler.codec.http.HttpResponseStatus.CONTINUE;
+import static io.netty.handler.codec.http.HttpResponseStatus.OK;
+import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelFutureListener;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.handler.codec.http.DefaultFullHttpResponse;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaderValues;
+import io.netty.handler.codec.http.HttpObject;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.HttpUtil;
+import io.netty.handler.codec.http.LastHttpContent;
+import io.netty.util.CharsetUtil;
+
+public class CustomHttpServerHandler extends SimpleChannelInboundHandler<Object> {
+
+    private HttpRequest request;
+    StringBuilder responseData = new StringBuilder();
+
+    @Override
+    public void channelReadComplete(ChannelHandlerContext ctx) {
+        ctx.flush();
+    }
+
+    @Override
+    protected void channelRead0(ChannelHandlerContext ctx, Object msg) {
+        if (msg instanceof HttpRequest) {
+            HttpRequest request = this.request = (HttpRequest) msg;
+
+            if (HttpUtil.is100ContinueExpected(request)) {
+                writeResponse(ctx);
+            }
+
+            responseData.setLength(0);
+            responseData.append(RequestUtils.formatParams(request));
+        }
+
+        responseData.append(RequestUtils.evaluateDecoderResult(request));
+
+        if (msg instanceof HttpContent) {
+            HttpContent httpContent = (HttpContent) msg;
+
+            responseData.append(RequestUtils.formatBody(httpContent));
+            responseData.append(RequestUtils.evaluateDecoderResult(request));
+
+            if (msg instanceof LastHttpContent) {
+                LastHttpContent trailer = (LastHttpContent) msg;
+                responseData.append(RequestUtils.prepareLastResponse(request, trailer));
+                writeResponse(ctx, trailer, responseData);
+            }
+        }
+    }
+
+    private void writeResponse(ChannelHandlerContext ctx) {
+        FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, CONTINUE, Unpooled.EMPTY_BUFFER);
+        ctx.write(response);
+    }
+
+    private void writeResponse(ChannelHandlerContext ctx, LastHttpContent trailer, StringBuilder responseData) {
+        boolean keepAlive = HttpUtil.isKeepAlive(request);
+
+        FullHttpResponse httpResponse = new DefaultFullHttpResponse(HTTP_1_1, ((HttpObject) trailer).decoderResult()
+            .isSuccess() ? OK : BAD_REQUEST, Unpooled.copiedBuffer(responseData.toString(), CharsetUtil.UTF_8));
+
+        httpResponse.headers()
+            .set(HttpHeaderNames.CONTENT_TYPE, "text/plain; charset=UTF-8");
+
+        if (keepAlive) {
+            httpResponse.headers()
+                .setInt(HttpHeaderNames.CONTENT_LENGTH, httpResponse.content()
+                    .readableBytes());
+            httpResponse.headers()
+                .set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE);
+        }
+
+        ctx.write(httpResponse);
+
+        if (!keepAlive) {
+            ctx.writeAndFlush(Unpooled.EMPTY_BUFFER)
+                .addListener(ChannelFutureListener.CLOSE);
+        }
+    }
+
+    @Override
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
+        cause.printStackTrace();
+        ctx.close();
+    }
+}
--- a/server-modules/netty/src/main/java/com/baeldung/http/server/HttpServer.java
+++ b/server-modules/netty/src/main/java/com/baeldung/http/server/HttpServer.java
@@ -0,0 +1,64 @@
+package com.baeldung.http.server;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelPipeline;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioServerSocketChannel;
+import io.netty.handler.codec.http.HttpRequestDecoder;
+import io.netty.handler.codec.http.HttpResponseEncoder;
+import io.netty.handler.logging.LogLevel;
+import io.netty.handler.logging.LoggingHandler;
+
+public class HttpServer {
+
+    private int port;
+    static Logger logger = LoggerFactory.getLogger(HttpServer.class);
+
+    public HttpServer(int port) {
+        this.port = port;
+    }
+
+    public static void main(String[] args) throws Exception {
+
+        int port = args.length > 0 ? Integer.parseInt(args[0]) : 8080;
+
+        new HttpServer(port).run();
+    }
+
+    public void run() throws Exception {
+        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
+        EventLoopGroup workerGroup = new NioEventLoopGroup();
+        try {
+            ServerBootstrap b = new ServerBootstrap();
+            b.group(bossGroup, workerGroup)
+                .channel(NioServerSocketChannel.class)
+                .handler(new LoggingHandler(LogLevel.INFO))
+                .childHandler(new ChannelInitializer<SocketChannel>() {
+                    @Override
+                    protected void initChannel(SocketChannel ch) throws Exception {
+                        ChannelPipeline p = ch.pipeline();
+                        p.addLast(new HttpRequestDecoder());
+                        p.addLast(new HttpResponseEncoder());
+                        p.addLast(new CustomHttpServerHandler());
+                    }
+                });
+
+            ChannelFuture f = b.bind(port)
+                .sync();
+            f.channel()
+                .closeFuture()
+                .sync();
+
+        } finally {
+            bossGroup.shutdownGracefully();
+            workerGroup.shutdownGracefully();
+        }
+    }
+}
--- a/server-modules/netty/src/main/java/com/baeldung/http/server/RequestUtils.java
+++ b/server-modules/netty/src/main/java/com/baeldung/http/server/RequestUtils.java
@@ -0,0 +1,86 @@
+package com.baeldung.http.server;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.handler.codec.DecoderResult;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.codec.http.HttpObject;
+import io.netty.handler.codec.http.HttpRequest;
+import io.netty.handler.codec.http.LastHttpContent;
+import io.netty.handler.codec.http.QueryStringDecoder;
+import io.netty.util.CharsetUtil;
+
+class RequestUtils {
+
+    static StringBuilder formatParams(HttpRequest request) {
+        StringBuilder responseData = new StringBuilder();
+        QueryStringDecoder queryStringDecoder = new QueryStringDecoder(request.uri());
+        Map<String, List<String>> params = queryStringDecoder.parameters();
+        if (!params.isEmpty()) {
+            for (Entry<String, List<String>> p : params.entrySet()) {
+                String key = p.getKey();
+                List<String> vals = p.getValue();
+                for (String val : vals) {
+                    responseData.append("Parameter: ")
+                        .append(key.toUpperCase())
+                        .append(" = ")
+                        .append(val.toUpperCase())
+                        .append("\r\n");
+                }
+            }
+            responseData.append("\r\n");
+        }
+        return responseData;
+    }
+
+    static StringBuilder formatBody(HttpContent httpContent) {
+        StringBuilder responseData = new StringBuilder();
+        ByteBuf content = httpContent.content();
+        if (content.isReadable()) {
+            responseData.append(content.toString(CharsetUtil.UTF_8)
+                .toUpperCase());
+            responseData.append("\r\n");
+        }
+        return responseData;
+    }
+
+    static StringBuilder evaluateDecoderResult(HttpObject o) {
+        StringBuilder responseData = new StringBuilder();
+        DecoderResult result = o.decoderResult();
+
+        if (!result.isSuccess()) {
+            responseData.append("..Decoder Failure: ");
+            responseData.append(result.cause());
+            responseData.append("\r\n");
+        }
+
+        return responseData;
+    }
+
+    static StringBuilder prepareLastResponse(HttpRequest request, LastHttpContent trailer) {
+        StringBuilder responseData = new StringBuilder();
+        responseData.append("Good Bye!\r\n");
+
+        if (!trailer.trailingHeaders()
+            .isEmpty()) {
+            responseData.append("\r\n");
+            for (CharSequence name : trailer.trailingHeaders()
+                .names()) {
+                for (CharSequence value : trailer.trailingHeaders()
+                    .getAll(name)) {
+                    responseData.append("P.S. Trailing Header: ");
+                    responseData.append(name)
+                        .append(" = ")
+                        .append(value)
+                        .append("\r\n");
+                }
+            }
+            responseData.append("\r\n");
+        }
+        return responseData;
+    }
+
+}
--- a/server-modules/netty/src/main/java/com/baeldung/netty/http2/Http2Util.java
+++ b/server-modules/netty/src/main/java/com/baeldung/netty/http2/Http2Util.java
@@ -0,0 +1,135 @@
+package com.baeldung.netty.http2;
+
+import static io.netty.handler.logging.LogLevel.INFO;
+
+import java.security.cert.CertificateException;
+
+import javax.net.ssl.SSLException;
+
+import com.baeldung.netty.http2.client.Http2ClientResponseHandler;
+import com.baeldung.netty.http2.client.Http2SettingsHandler;
+import com.baeldung.netty.http2.server.Http2ServerResponseHandler;
+
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelPipeline;
+import io.netty.handler.codec.http.DefaultFullHttpRequest;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaderValues;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.HttpScheme;
+import io.netty.handler.codec.http.HttpVersion;
+import io.netty.handler.codec.http2.DefaultHttp2Connection;
+import io.netty.handler.codec.http2.DelegatingDecompressorFrameListener;
+import io.netty.handler.codec.http2.Http2Connection;
+import io.netty.handler.codec.http2.Http2FrameCodecBuilder;
+import io.netty.handler.codec.http2.Http2FrameLogger;
+import io.netty.handler.codec.http2.Http2SecurityUtil;
+import io.netty.handler.codec.http2.HttpConversionUtil;
+import io.netty.handler.codec.http2.HttpToHttp2ConnectionHandler;
+import io.netty.handler.codec.http2.HttpToHttp2ConnectionHandlerBuilder;
+import io.netty.handler.codec.http2.InboundHttp2ToHttpAdapterBuilder;
+import io.netty.handler.ssl.ApplicationProtocolConfig;
+import io.netty.handler.ssl.ApplicationProtocolConfig.Protocol;
+import io.netty.handler.ssl.ApplicationProtocolConfig.SelectedListenerFailureBehavior;
+import io.netty.handler.ssl.ApplicationProtocolConfig.SelectorFailureBehavior;
+import io.netty.handler.ssl.ApplicationProtocolNames;
+import io.netty.handler.ssl.ApplicationProtocolNegotiationHandler;
+import io.netty.handler.ssl.SslContext;
+import io.netty.handler.ssl.SslContextBuilder;
+import io.netty.handler.ssl.SslProvider;
+import io.netty.handler.ssl.SupportedCipherSuiteFilter;
+import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
+import io.netty.handler.ssl.util.SelfSignedCertificate;
+
+public class Http2Util {
+    public static SslContext createSSLContext(boolean isServer) throws SSLException, CertificateException {
+
+        SslContext sslCtx;
+
+        SelfSignedCertificate ssc = new SelfSignedCertificate();
+
+        if (isServer) {
+            sslCtx = SslContextBuilder.forServer(ssc.certificate(), ssc.privateKey())
+                .sslProvider(SslProvider.JDK)
+                .ciphers(Http2SecurityUtil.CIPHERS, SupportedCipherSuiteFilter.INSTANCE)
+                .applicationProtocolConfig(new ApplicationProtocolConfig(Protocol.ALPN,
+                    SelectorFailureBehavior.NO_ADVERTISE,
+                    SelectedListenerFailureBehavior.ACCEPT, ApplicationProtocolNames.HTTP_2, ApplicationProtocolNames.HTTP_1_1))
+                .build();
+        } else {
+            sslCtx = SslContextBuilder.forClient()
+                .sslProvider(SslProvider.JDK)
+                .ciphers(Http2SecurityUtil.CIPHERS, SupportedCipherSuiteFilter.INSTANCE)
+                .trustManager(InsecureTrustManagerFactory.INSTANCE)
+                .applicationProtocolConfig(new ApplicationProtocolConfig(Protocol.ALPN,
+                    SelectorFailureBehavior.NO_ADVERTISE,
+                    SelectedListenerFailureBehavior.ACCEPT, ApplicationProtocolNames.HTTP_2))
+                .build();
+        }
+        return sslCtx;
+
+    }
+
+    public static ApplicationProtocolNegotiationHandler getServerAPNHandler() {
+        ApplicationProtocolNegotiationHandler serverAPNHandler = new ApplicationProtocolNegotiationHandler(ApplicationProtocolNames.HTTP_2) {
+
+            @Override
+            protected void configurePipeline(ChannelHandlerContext ctx, String protocol) throws Exception {
+                if (ApplicationProtocolNames.HTTP_2.equals(protocol)) {
+                    ctx.pipeline()
+                        .addLast(Http2FrameCodecBuilder.forServer()
+                            .build(), new Http2ServerResponseHandler());
+                    return;
+                }
+                throw new IllegalStateException("Protocol: " + protocol + " not supported");
+            }
+        };
+        return serverAPNHandler;
+
+    }
+
+    public static ApplicationProtocolNegotiationHandler getClientAPNHandler(int maxContentLength, Http2SettingsHandler settingsHandler, Http2ClientResponseHandler responseHandler) {
+        final Http2FrameLogger logger = new Http2FrameLogger(INFO, Http2Util.class);
+        final Http2Connection connection = new DefaultHttp2Connection(false);
+
+        HttpToHttp2ConnectionHandler connectionHandler = new HttpToHttp2ConnectionHandlerBuilder()
+            .frameListener(new DelegatingDecompressorFrameListener(connection, new InboundHttp2ToHttpAdapterBuilder(connection).maxContentLength(maxContentLength)
+            .propagateSettings(true)
+            .build()))
+            .frameLogger(logger)
+            .connection(connection)
+            .build();
+
+        ApplicationProtocolNegotiationHandler clientAPNHandler = new ApplicationProtocolNegotiationHandler(ApplicationProtocolNames.HTTP_2) {
+            @Override
+            protected void configurePipeline(ChannelHandlerContext ctx, String protocol) {
+                if (ApplicationProtocolNames.HTTP_2.equals(protocol)) {
+                    ChannelPipeline p = ctx.pipeline();
+                    p.addLast(connectionHandler);
+                    p.addLast(settingsHandler, responseHandler);
+                    return;
+                }
+                ctx.close();
+                throw new IllegalStateException("Protocol: " + protocol + " not supported");
+            }
+        };
+
+        return clientAPNHandler;
+
+    }
+
+    public static FullHttpRequest createGetRequest(String host, int port) {
+        FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.valueOf("HTTP/2.0"), HttpMethod.GET, "/", Unpooled.EMPTY_BUFFER);
+        request.headers()
+            .add(HttpHeaderNames.HOST, new String(host + ":" + port));
+        request.headers()
+            .add(HttpConversionUtil.ExtensionHeaderNames.SCHEME.text(), HttpScheme.HTTPS);
+        request.headers()
+            .add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.GZIP);
+        request.headers()
+            .add(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.DEFLATE);
+        return request;
+    }
+}
--- a/server-modules/netty/src/main/java/com/baeldung/netty/http2/client/Http2ClientInitializer.java
+++ b/server-modules/netty/src/main/java/com/baeldung/netty/http2/client/Http2ClientInitializer.java
@@ -0,0 +1,46 @@
+package com.baeldung.netty.http2.client;
+
+import com.baeldung.netty.http2.Http2Util;
+
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelPipeline;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.handler.ssl.SslContext;
+
+public class Http2ClientInitializer extends ChannelInitializer<SocketChannel> {
+
+    private final SslContext sslCtx;
+    private final int maxContentLength;
+    private Http2SettingsHandler settingsHandler;
+    private Http2ClientResponseHandler responseHandler;
+    private String host;
+    private int port;
+
+    public Http2ClientInitializer(SslContext sslCtx, int maxContentLength, String host, int port) {
+        this.sslCtx = sslCtx;
+        this.maxContentLength = maxContentLength;
+        this.host = host;
+        this.port = port;
+    }
+
+    @Override
+    public void initChannel(SocketChannel ch) throws Exception {
+
+        settingsHandler = new Http2SettingsHandler(ch.newPromise());
+        responseHandler = new Http2ClientResponseHandler();
+        
+        if (sslCtx != null) {
+            ChannelPipeline pipeline = ch.pipeline();
+            pipeline.addLast(sslCtx.newHandler(ch.alloc(), host, port));
+            pipeline.addLast(Http2Util.getClientAPNHandler(maxContentLength, settingsHandler, responseHandler));
+        }
+    }
+
+    public Http2SettingsHandler getSettingsHandler() {
+        return settingsHandler;
+    }
+    
+    public Http2ClientResponseHandler getResponseHandler() {
+        return responseHandler;
+    }
+}
--- a/server-modules/netty/src/main/java/com/baeldung/netty/http2/client/Http2ClientResponseHandler.java
+++ b/server-modules/netty/src/main/java/com/baeldung/netty/http2/client/Http2ClientResponseHandler.java
@@ -0,0 +1,128 @@
+package com.baeldung.netty.http2.client;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.concurrent.TimeUnit;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelPromise;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.handler.codec.http.FullHttpResponse;
+import io.netty.handler.codec.http2.HttpConversionUtil;
+import io.netty.util.CharsetUtil;
+
+public class Http2ClientResponseHandler extends SimpleChannelInboundHandler<FullHttpResponse> {
+
+    private final Logger logger = LoggerFactory.getLogger(Http2ClientResponseHandler.class);
+    private final Map<Integer, MapValues> streamidMap;
+
+    public Http2ClientResponseHandler() {
+        streamidMap = new HashMap<Integer, MapValues>();
+    }
+
+    public MapValues put(int streamId, ChannelFuture writeFuture, ChannelPromise promise) {
+        return streamidMap.put(streamId, new MapValues(writeFuture, promise));
+    }
+
+    public String awaitResponses(long timeout, TimeUnit unit) {
+
+        Iterator<Entry<Integer, MapValues>> itr = streamidMap.entrySet()
+            .iterator();
+        
+        String response = null;
+
+        while (itr.hasNext()) {
+            Entry<Integer, MapValues> entry = itr.next();
+            ChannelFuture writeFuture = entry.getValue()
+                .getWriteFuture();
+
+            if (!writeFuture.awaitUninterruptibly(timeout, unit)) {
+                throw new IllegalStateException("Timed out waiting to write for stream id " + entry.getKey());
+            }
+            if (!writeFuture.isSuccess()) {
+                throw new RuntimeException(writeFuture.cause());
+            }
+            ChannelPromise promise = entry.getValue()
+                .getPromise();
+
+            if (!promise.awaitUninterruptibly(timeout, unit)) {
+                throw new IllegalStateException("Timed out waiting for response on stream id " + entry.getKey());
+            }
+            if (!promise.isSuccess()) {
+                throw new RuntimeException(promise.cause());
+            }
+            logger.info("---Stream id: " + entry.getKey() + " received---");
+            response = entry.getValue().getResponse();
+            
+            itr.remove();
+        }
+        
+        return response;
+
+    }
+
+    @Override
+    protected void channelRead0(ChannelHandlerContext ctx, FullHttpResponse msg) throws Exception {
+        Integer streamId = msg.headers()
+            .getInt(HttpConversionUtil.ExtensionHeaderNames.STREAM_ID.text());
+        if (streamId == null) {
+            logger.error("HttpResponseHandler unexpected message received: " + msg);
+            return;
+        }
+
+        MapValues value = streamidMap.get(streamId);
+
+        if (value == null) {
+            logger.error("Message received for unknown stream id " + streamId);
+            ctx.close();
+        } else {
+            ByteBuf content = msg.content();
+            if (content.isReadable()) {
+                int contentLength = content.readableBytes();
+                byte[] arr = new byte[contentLength];
+                content.readBytes(arr);
+                String response = new String(arr, 0, contentLength, CharsetUtil.UTF_8);
+                logger.info("Response from Server: "+ (response));
+                value.setResponse(response);
+            }
+            
+            value.getPromise()
+                .setSuccess();
+        }
+    }
+
+    public static class MapValues {
+        ChannelFuture writeFuture;
+        ChannelPromise promise;
+        String response;
+
+        public String getResponse() {
+            return response;
+        }
+
+        public void setResponse(String response) {
+            this.response = response;
+        }
+
+        public MapValues(ChannelFuture writeFuture2, ChannelPromise promise2) {
+            this.writeFuture = writeFuture2;
+            this.promise = promise2;
+        }
+
+        public ChannelFuture getWriteFuture() {
+            return writeFuture;
+        }
+
+        public ChannelPromise getPromise() {
+            return promise;
+        }
+
+    }
+}
--- a/server-modules/netty/src/main/java/com/baeldung/netty/http2/client/Http2SettingsHandler.java
+++ b/server-modules/netty/src/main/java/com/baeldung/netty/http2/client/Http2SettingsHandler.java
@@ -0,0 +1,30 @@
+package com.baeldung.netty.http2.client;
+
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelPromise;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.handler.codec.http2.Http2Settings;
+
+import java.util.concurrent.TimeUnit;
+
+public class Http2SettingsHandler extends SimpleChannelInboundHandler<Http2Settings> {
+    private final ChannelPromise promise;
+
+    public Http2SettingsHandler(ChannelPromise promise) {
+        this.promise = promise;
+    }
+
+    public void awaitSettings(long timeout, TimeUnit unit) throws Exception {
+        if (!promise.awaitUninterruptibly(timeout, unit)) {
+            throw new IllegalStateException("Timed out waiting for settings");
+        }
+    }
+
+    @Override
+    protected void channelRead0(ChannelHandlerContext ctx, Http2Settings msg) throws Exception {
+        promise.setSuccess();
+
+        ctx.pipeline()
+            .remove(this);
+    }
+}
--- a/server-modules/netty/src/main/java/com/baeldung/netty/http2/server/Http2Server.java
+++ b/server-modules/netty/src/main/java/com/baeldung/netty/http2/server/Http2Server.java
@@ -0,0 +1,59 @@
+package com.baeldung.netty.http2.server;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.baeldung.netty.http2.Http2Util;
+
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelOption;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioServerSocketChannel;
+import io.netty.handler.logging.LogLevel;
+import io.netty.handler.logging.LoggingHandler;
+import io.netty.handler.ssl.SslContext;
+
+public final class Http2Server {
+
+    private static final int PORT = 8443;
+    private static final Logger logger = LoggerFactory.getLogger(Http2Server.class);
+
+    public static void main(String[] args) throws Exception {
+        SslContext sslCtx = Http2Util.createSSLContext(true);
+
+        EventLoopGroup group = new NioEventLoopGroup();
+        try {
+            ServerBootstrap b = new ServerBootstrap();
+            b.option(ChannelOption.SO_BACKLOG, 1024);
+            b.group(group)
+                .channel(NioServerSocketChannel.class)
+                .handler(new LoggingHandler(LogLevel.INFO))
+                .childHandler(new ChannelInitializer<SocketChannel>() {
+                    @Override
+                    protected void initChannel(SocketChannel ch) throws Exception {
+                        if (sslCtx != null) {
+                            ch.pipeline()
+                                .addLast(sslCtx.newHandler(ch.alloc()), Http2Util.getServerAPNHandler());
+                        }
+                    }
+
+                });
+
+            Channel ch = b.bind(PORT)
+                .sync()
+                .channel();
+
+            logger.info("HTTP/2 Server is listening on https://127.0.0.1:" + PORT + '/');
+
+            ch.closeFuture()
+                .sync();
+        } finally {
+            group.shutdownGracefully();
+        }
+    }
+
+}
--- a/server-modules/netty/src/main/java/com/baeldung/netty/http2/server/Http2ServerResponseHandler.java
+++ b/server-modules/netty/src/main/java/com/baeldung/netty/http2/server/Http2ServerResponseHandler.java
@@ -0,0 +1,52 @@
+package com.baeldung.netty.http2.server;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.ChannelDuplexHandler;
+import io.netty.channel.ChannelHandler.Sharable;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.http.HttpResponseStatus;
+import io.netty.handler.codec.http2.DefaultHttp2DataFrame;
+import io.netty.handler.codec.http2.DefaultHttp2Headers;
+import io.netty.handler.codec.http2.DefaultHttp2HeadersFrame;
+import io.netty.handler.codec.http2.Http2Headers;
+import io.netty.handler.codec.http2.Http2HeadersFrame;
+import io.netty.util.CharsetUtil;
+
+@Sharable
+public class Http2ServerResponseHandler extends ChannelDuplexHandler {
+
+    static final ByteBuf RESPONSE_BYTES = Unpooled.unreleasableBuffer(Unpooled.copiedBuffer("Hello World", CharsetUtil.UTF_8));
+
+    @Override
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+        super.exceptionCaught(ctx, cause);
+        cause.printStackTrace();
+        ctx.close();
+    }
+
+    @Override
+    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
+        if (msg instanceof Http2HeadersFrame) {
+            Http2HeadersFrame msgHeader = (Http2HeadersFrame) msg;
+            if (msgHeader.isEndStream()) {
+                ByteBuf content = ctx.alloc()
+                    .buffer();
+                content.writeBytes(RESPONSE_BYTES.duplicate());
+
+                Http2Headers headers = new DefaultHttp2Headers().status(HttpResponseStatus.OK.codeAsText());
+                ctx.write(new DefaultHttp2HeadersFrame(headers).stream(msgHeader.stream()));
+                ctx.write(new DefaultHttp2DataFrame(content, true).stream(msgHeader.stream()));
+            }
+
+        } else {
+            super.channelRead(ctx, msg);
+        }
+    }
+
+    @Override
+    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
+        ctx.flush();
+    }
+
+}
--- a/server-modules/netty/src/main/resources/logback.xml
+++ b/server-modules/netty/src/main/resources/logback.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
--- a/server-modules/netty/src/test/java/com/baeldung/http/server/HttpServerLiveTest.java
+++ b/server-modules/netty/src/test/java/com/baeldung/http/server/HttpServerLiveTest.java
@@ -0,0 +1,177 @@
+package com.baeldung.http.server;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import io.netty.bootstrap.Bootstrap;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelPipeline;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.handler.codec.http.DefaultFullHttpRequest;
+import io.netty.handler.codec.http.HttpClientCodec;
+import io.netty.handler.codec.http.HttpContent;
+import io.netty.handler.codec.http.HttpContentDecompressor;
+import io.netty.handler.codec.http.HttpHeaderNames;
+import io.netty.handler.codec.http.HttpHeaderValues;
+import io.netty.handler.codec.http.HttpMethod;
+import io.netty.handler.codec.http.HttpObject;
+import io.netty.handler.codec.http.HttpResponse;
+import io.netty.handler.codec.http.HttpUtil;
+import io.netty.handler.codec.http.HttpVersion;
+import io.netty.handler.codec.http.LastHttpContent;
+import io.netty.handler.codec.http.cookie.ClientCookieEncoder;
+import io.netty.handler.codec.http.cookie.DefaultCookie;
+import io.netty.util.CharsetUtil;
+
+//Ensure the server class - HttpServer.java is already started before running this test
+public class HttpServerLiveTest {
+
+    private static final String HOST = "127.0.0.1";
+    private static final int PORT = 8080;
+    private Channel channel;
+    private EventLoopGroup group = new NioEventLoopGroup();
+    ResponseAggregator response = new ResponseAggregator();
+
+    @Before
+    public void setup() throws Exception {
+        Bootstrap b = new Bootstrap();
+        b.group(group)
+            .channel(NioSocketChannel.class)
+            .handler(new ChannelInitializer<SocketChannel>() {
+
+                @Override
+                protected void initChannel(SocketChannel ch) throws Exception {
+                    ChannelPipeline p = ch.pipeline();
+                    p.addLast(new HttpClientCodec());
+                    p.addLast(new HttpContentDecompressor());
+                    p.addLast(new SimpleChannelInboundHandler<HttpObject>() {
+                        @Override
+                        protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
+                            response = prepareResponse(ctx, msg, response);
+                        }
+                    });
+                }
+            });
+
+        channel = b.connect(HOST, PORT)
+            .sync()
+            .channel();
+    }
+
+    @Test
+    public void whenPostSent_thenContentReceivedInUppercase() throws Exception {
+        String body = "Hello World!";
+
+        DefaultFullHttpRequest request = createRequest(body);
+
+        channel.writeAndFlush(request);
+        Thread.sleep(200);
+
+        assertEquals(200, response.getStatus());
+        assertEquals("HTTP/1.1", response.getVersion());
+
+        assertTrue(response.getContent()
+            .contains(body.toUpperCase()));
+    }
+
+    @Test
+    public void whenGetSent_thenResponseOK() throws Exception {
+        DefaultFullHttpRequest request = createRequest(null);
+
+        channel.writeAndFlush(request);
+        Thread.sleep(200);
+
+        assertEquals(200, response.getStatus());
+        assertEquals("HTTP/1.1", response.getVersion());
+
+    }
+
+    @After
+    public void cleanup() throws InterruptedException {
+        channel.closeFuture()
+            .sync();
+        group.shutdownGracefully();
+    }
+
+    private static DefaultFullHttpRequest createRequest(final CharSequence body) throws Exception {
+        DefaultFullHttpRequest request;
+        if (body != null) {
+            request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.POST, "/");
+            request.content()
+                .writeBytes(body.toString()
+                    .getBytes(CharsetUtil.UTF_8.name()));
+            request.headers()
+                .set(HttpHeaderNames.CONTENT_TYPE, "application/json");
+            request.headers()
+                .set(HttpHeaderNames.CONTENT_LENGTH, request.content()
+                    .readableBytes());
+        } else {
+            request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, "/", Unpooled.EMPTY_BUFFER);
+            request.headers()
+                .set(HttpHeaderNames.COOKIE, ClientCookieEncoder.STRICT.encode(new DefaultCookie("my-cookie", "foo")));
+        }
+
+        request.headers()
+            .set(HttpHeaderNames.HOST, HOST);
+        request.headers()
+            .set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE);
+
+        return request;
+    }
+
+    private static ResponseAggregator prepareResponse(ChannelHandlerContext ctx, HttpObject msg, ResponseAggregator responseAgg) {
+
+        if (msg instanceof HttpResponse) {
+            HttpResponse response = (HttpResponse) msg;
+
+            responseAgg.setStatus(response.status()
+                .code());
+
+            responseAgg.setVersion(response.protocolVersion()
+                .text());
+
+            if (!response.headers()
+                .isEmpty()) {
+                Map<String, String> headers = new HashMap<String, String>();
+                for (CharSequence name : response.headers()
+                    .names()) {
+                    for (CharSequence value : response.headers()
+                        .getAll(name)) {
+                        headers.put(name.toString(), value.toString());
+                    }
+                }
+                responseAgg.setHeaders(headers);
+            }
+            if (HttpUtil.isTransferEncodingChunked(response)) {
+                responseAgg.setChunked(true);
+            } else {
+                responseAgg.setChunked(false);
+            }
+        }
+        if (msg instanceof HttpContent) {
+            HttpContent content = (HttpContent) msg;
+            String responseData = content.content()
+                .toString(CharsetUtil.UTF_8);
+
+            if (content instanceof LastHttpContent) {
+                responseAgg.setContent(responseData + "} End Of Content");
+                ctx.close();
+            }
+        }
+        return responseAgg;
+    }
+}
--- a/server-modules/netty/src/test/java/com/baeldung/http/server/ResponseAggregator.java
+++ b/server-modules/netty/src/test/java/com/baeldung/http/server/ResponseAggregator.java
@@ -0,0 +1,52 @@
+package com.baeldung.http.server;
+
+import java.util.Map;
+
+public class ResponseAggregator {
+    int status;
+    String version;
+    Map<String, String> headers;
+    boolean isChunked;
+    String content;
+
+    public int getStatus() {
+        return status;
+    }
+
+    public void setStatus(int status) {
+        this.status = status;
+    }
+
+    public String getVersion() {
+        return version;
+    }
+
+    public void setVersion(String version) {
+        this.version = version;
+    }
+
+    public Map<String, String> getHeaders() {
+        return headers;
+    }
+
+    public void setHeaders(Map<String, String> headers) {
+        this.headers = headers;
+    }
+
+    public boolean isChunked() {
+        return isChunked;
+    }
+
+    public void setChunked(boolean isChunked) {
+        this.isChunked = isChunked;
+    }
+
+    public String getContent() {
+        return content;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+
+}
--- a/server-modules/netty/src/test/java/com/baeldung/netty/Http2ClientLiveTest.java
+++ b/server-modules/netty/src/test/java/com/baeldung/netty/Http2ClientLiveTest.java
@@ -0,0 +1,91 @@
+package com.baeldung.netty;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.concurrent.TimeUnit;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.baeldung.netty.http2.Http2Util;
+import com.baeldung.netty.http2.client.Http2ClientInitializer;
+import com.baeldung.netty.http2.client.Http2ClientResponseHandler;
+import com.baeldung.netty.http2.client.Http2SettingsHandler;
+
+import io.netty.bootstrap.Bootstrap;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelOption;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.handler.codec.http.FullHttpRequest;
+import io.netty.handler.ssl.SslContext;
+
+//Ensure the server class - Http2Server.java is already started before running this test
+public class Http2ClientLiveTest {
+
+    private static final Logger logger = LoggerFactory.getLogger(Http2ClientLiveTest.class);
+
+    private static final String HOST = "127.0.0.1";
+    private static final int PORT = 8443;
+    private SslContext sslCtx;
+    private Channel channel;
+
+    @Before
+    public void setup() throws Exception {
+        sslCtx = Http2Util.createSSLContext(false);
+    }
+
+    @Test
+    public void whenRequestSent_thenHelloWorldReceived() throws Exception {
+
+        EventLoopGroup workerGroup = new NioEventLoopGroup();
+        Http2ClientInitializer initializer = new Http2ClientInitializer(sslCtx, Integer.MAX_VALUE, HOST, PORT);
+
+        try {
+            Bootstrap b = new Bootstrap();
+            b.group(workerGroup);
+            b.channel(NioSocketChannel.class);
+            b.option(ChannelOption.SO_KEEPALIVE, true);
+            b.remoteAddress(HOST, PORT);
+            b.handler(initializer);
+
+            channel = b.connect()
+                .syncUninterruptibly()
+                .channel();
+
+            logger.info("Connected to [" + HOST + ':' + PORT + ']');
+
+            Http2SettingsHandler http2SettingsHandler = initializer.getSettingsHandler();
+            http2SettingsHandler.awaitSettings(60, TimeUnit.SECONDS);
+
+            logger.info("Sending request(s)...");
+
+            FullHttpRequest request = Http2Util.createGetRequest(HOST, PORT);
+
+            Http2ClientResponseHandler responseHandler = initializer.getResponseHandler();
+            int streamId = 3;
+
+            responseHandler.put(streamId, channel.write(request), channel.newPromise());
+            channel.flush();
+            String response = responseHandler.awaitResponses(60, TimeUnit.SECONDS);
+
+            assertEquals("Hello World", response);
+
+            logger.info("Finished HTTP/2 request(s)");
+
+        } finally {
+            workerGroup.shutdownGracefully();
+        }
+
+    }
+
+    @After
+    public void cleanup() {
+        channel.close()
+            .syncUninterruptibly();
+    }
+}
--- a/server-modules/pom.xml
+++ b/server-modules/pom.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>server-modules</artifactId>
+    <name>server-modules</name>
+    <packaging>pom</packaging>
+
+    <parent>
+        <artifactId>parent-modules</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <modules>
+        <module>apache-tomcat</module>
+        <module>netty</module>
+        <module>undertow</module>
+        <module>wildfly</module>
+    </modules>
+</project>
--- a/server-modules/undertow/README.md
+++ b/server-modules/undertow/README.md
@@ -0,0 +1,6 @@
+## Undertow
+
+This module contains articles about JBoss Undertow
+
+### Relevant Articles:
+- [Introduction to JBoss Undertow](https://www.baeldung.com/jboss-undertow)
--- a/server-modules/undertow/pom.xml
+++ b/server-modules/undertow/pom.xml
@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung.undertow</groupId>
+    <artifactId>undertow</artifactId>
+    <name>undertow</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>server-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.undertow</groupId>
+            <artifactId>undertow-servlet</artifactId>
+            <version>${undertow-servlet.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>${project.artifactId}</finalName>
+        <plugins>
+            <!-- disabling shade plugin as it is causing issues with creating dependency-reduced-pom -->
+            <!-- on the build server <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-shade-plugin</artifactId> -->
+            <!-- <version>${maven-shade-plugin.version}</version> <executions> <execution> <phase>package</phase> -->
+            <!--<goals> <goal>shade</goal> </goals> </execution> </executions> </plugin> -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <version>${maven-jar-plugin.version}</version>
+                <configuration>
+                    <archive>
+                        <manifest>
+                            <mainClass>com.baeldung.undertow.SimpleServer</mainClass>
+                        </manifest>
+                    </archive>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <undertow-servlet.version>1.4.18.Final</undertow-servlet.version>
+        <!--<maven-shade-plugin.version>2.4.3</maven-shade-plugin.version> -->
+        <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
+    </properties>
+
+</project>
--- a/server-modules/undertow/src/main/java/com/baeldung/undertow/SimpleServer.java
+++ b/server-modules/undertow/src/main/java/com/baeldung/undertow/SimpleServer.java
@@ -0,0 +1,16 @@
+package com.baeldung.undertow;
+
+import io.undertow.Undertow;
+import io.undertow.util.Headers;
+
+public class SimpleServer {
+
+    public static void main(String[] args) {
+        Undertow server = Undertow.builder().addHttpListener(8080, "localhost").setHandler(exchange -> {
+            exchange.getResponseHeaders().put(Headers.CONTENT_TYPE, "text/plain");
+            exchange.getResponseSender().send("Hello Baeldung");
+        }).build();
+        server.start();
+    }
+
+}
--- a/server-modules/undertow/src/main/java/com/baeldung/undertow/ftp/FileServer.java
+++ b/server-modules/undertow/src/main/java/com/baeldung/undertow/ftp/FileServer.java
@@ -0,0 +1,20 @@
+package com.baeldung.undertow.ftp;
+
+import io.undertow.Undertow;
+import io.undertow.server.handlers.resource.PathResourceManager;
+
+import java.nio.file.Paths;
+
+import static io.undertow.Handlers.resource;
+
+public class FileServer {
+
+    public static void main(String[] args) {
+        Undertow server = Undertow.builder().addHttpListener(8080, "localhost")
+          .setHandler(resource(new PathResourceManager(Paths.get(System.getProperty("user.home")), 100))
+            .setDirectoryListingEnabled(true))
+          .build();
+        server.start();
+    }
+
+}
--- a/server-modules/undertow/src/main/java/com/baeldung/undertow/secure/CustomIdentityManager.java
+++ b/server-modules/undertow/src/main/java/com/baeldung/undertow/secure/CustomIdentityManager.java
@@ -0,0 +1,73 @@
+package com.baeldung.undertow.secure;
+
+import java.security.Principal;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Set;
+
+import io.undertow.security.idm.Account;
+import io.undertow.security.idm.Credential;
+import io.undertow.security.idm.IdentityManager;
+import io.undertow.security.idm.PasswordCredential;
+
+public class CustomIdentityManager implements IdentityManager {
+
+    private final Map<String, char[]> users;
+
+    CustomIdentityManager(final Map<String, char[]> users) {
+        this.users = users;
+    }
+
+    @Override
+    public Account verify(Account account) {
+        return account;
+    }
+
+    @Override
+    public Account verify(Credential credential) {
+        return null;
+    }
+
+    @Override
+    public Account verify(String id, Credential credential) {
+        Account account = getAccount(id);
+        if (account != null && verifyCredential(account, credential)) {
+            return account;
+        }
+        return null;
+    }
+
+    private boolean verifyCredential(Account account, Credential credential) {
+        if (credential instanceof PasswordCredential) {
+            char[] password = ((PasswordCredential) credential).getPassword();
+            char[] expectedPassword = users.get(account.getPrincipal().getName());
+
+            return Arrays.equals(password, expectedPassword);
+        }
+        return false;
+    }
+
+    private Account getAccount(final String id) {
+        if (users.containsKey(id)) {
+            return new Account() {
+
+                private static final long serialVersionUID = 1L;
+
+                private final Principal principal = () -> id;
+
+                @Override
+                public Principal getPrincipal() {
+                    return principal;
+                }
+
+                @Override
+                public Set<String> getRoles() {
+                    return Collections.emptySet();
+                }
+            };
+        }
+        return null;
+    }
+
+}
--- a/server-modules/undertow/src/main/java/com/baeldung/undertow/secure/SecureServer.java
+++ b/server-modules/undertow/src/main/java/com/baeldung/undertow/secure/SecureServer.java
@@ -0,0 +1,54 @@
+package com.baeldung.undertow.secure;
+
+import io.undertow.Undertow;
+import io.undertow.io.IoCallback;
+import io.undertow.security.api.AuthenticationMechanism;
+import io.undertow.security.api.AuthenticationMode;
+import io.undertow.security.api.SecurityContext;
+import io.undertow.security.handlers.AuthenticationCallHandler;
+import io.undertow.security.handlers.AuthenticationConstraintHandler;
+import io.undertow.security.handlers.AuthenticationMechanismsHandler;
+import io.undertow.security.handlers.SecurityInitialHandler;
+import io.undertow.security.idm.IdentityManager;
+import io.undertow.security.impl.BasicAuthenticationMechanism;
+import io.undertow.server.HttpHandler;
+import io.undertow.server.HttpServerExchange;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class SecureServer {
+
+    public static void main(String[] args) {
+        final Map<String, char[]> users = new HashMap<>(2);
+        users.put("root", "password".toCharArray());
+        users.put("admin", "password".toCharArray());
+
+        final IdentityManager idm = new CustomIdentityManager(users);
+
+        Undertow server = Undertow.builder()
+          .addHttpListener(8080, "localhost")
+          .setHandler(addSecurity(SecureServer::setExchange, idm)).build();
+
+        server.start();
+    }
+
+    private static void setExchange(HttpServerExchange exchange) {
+        final SecurityContext context = exchange.getSecurityContext();
+        exchange.getResponseSender().send("Hello " + context.getAuthenticatedAccount().getPrincipal().getName(), IoCallback.END_EXCHANGE);
+    }
+
+    private static HttpHandler addSecurity(final HttpHandler toWrap, final IdentityManager identityManager) {
+        HttpHandler handler = toWrap;
+        handler = new AuthenticationCallHandler(handler);
+        handler = new AuthenticationConstraintHandler(handler);
+        final List<AuthenticationMechanism> mechanisms = Collections
+          .singletonList(new BasicAuthenticationMechanism("Baeldung_Realm"));
+        handler = new AuthenticationMechanismsHandler(handler, mechanisms);
+        handler = new SecurityInitialHandler(AuthenticationMode.PRO_ACTIVE, identityManager, handler);
+        return handler;
+    }
+
+}
--- a/server-modules/undertow/src/main/java/com/baeldung/undertow/socket/SocketServer.java
+++ b/server-modules/undertow/src/main/java/com/baeldung/undertow/socket/SocketServer.java
@@ -0,0 +1,40 @@
+package com.baeldung.undertow.socket;
+
+import io.undertow.Undertow;
+import io.undertow.server.handlers.resource.ClassPathResourceManager;
+import io.undertow.websockets.core.AbstractReceiveListener;
+import io.undertow.websockets.core.BufferedTextMessage;
+import io.undertow.websockets.core.WebSocketChannel;
+import io.undertow.websockets.core.WebSockets;
+
+import static io.undertow.Handlers.path;
+import static io.undertow.Handlers.resource;
+import static io.undertow.Handlers.websocket;
+
+public class SocketServer {
+
+    public static void main(String[] args) {
+        Undertow server = Undertow.builder().addHttpListener(8080, "localhost")
+                .setHandler(path().addPrefixPath("/baeldungApp", websocket((exchange, channel) -> {
+                    channel.getReceiveSetter().set(getListener());
+                    channel.resumeReceives();
+                })).addPrefixPath("/", resource(new ClassPathResourceManager(SocketServer.class.getClassLoader(),
+                        SocketServer.class.getPackage())).addWelcomeFiles("index.html")))
+                .build();
+
+        server.start();
+    }
+
+    private static AbstractReceiveListener getListener() {
+        return new AbstractReceiveListener() {
+            @Override
+            protected void onFullTextMessage(WebSocketChannel channel, BufferedTextMessage message) {
+                final String messageData = message.getData();
+                for (WebSocketChannel session : channel.getPeerConnections()) {
+                    WebSockets.sendText(messageData, session, null);
+                }
+            }
+        };
+    }
+    
+}
--- a/server-modules/undertow/src/main/resources/logback.xml
+++ b/server-modules/undertow/src/main/resources/logback.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
--- a/server-modules/wildfly/README.md
+++ b/server-modules/wildfly/README.md
@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [How to Set Up a WildFly Server](https://www.baeldung.com/wildfly-server-setup)
--- a/server-modules/wildfly/pom.xml
+++ b/server-modules/wildfly/pom.xml
@@ -0,0 +1,77 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>org.springframework</groupId>
+    <artifactId>wildfly</artifactId>
+    <version>0.1.0</version>
+    <name>wildfly</name>
+    <packaging>war</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-boot-2</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.springframework.boot</groupId>
+                    <artifactId>spring-boot-starter-tomcat</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <!-- tag::actuator[] -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+        <!-- end::actuator[] -->
+        <!-- tag::tests[] -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <!-- end::tests[] -->
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>integration-test</goal>
+                            <goal>verify</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-war-plugin</artifactId>
+                <configuration>
+                    <archive>
+                        <manifestEntries>
+                            <Dependencies>jdk.unsupported</Dependencies>
+                        </manifestEntries>
+                    </archive>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>
--- a/server-modules/wildfly/src/main/java/hello/Application.java
+++ b/server-modules/wildfly/src/main/java/hello/Application.java
@@ -0,0 +1,40 @@
+package hello;
+
+import java.util.Arrays;
+
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class Application extends SpringBootServletInitializer {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+    @Override
+    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
+        return application.sources(Application.class);
+    }
+
+    @Bean
+    public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
+        return args -> {
+
+            System.out.println("Let's inspect the beans provided by Spring Boot:");
+
+            String[] beanNames = ctx.getBeanDefinitionNames();
+            Arrays.sort(beanNames);
+            for (String beanName : beanNames) {
+                System.out.println(beanName);
+            }
+
+        };
+    }
+
+}
--- a/server-modules/wildfly/src/main/java/hello/HelloController.java
+++ b/server-modules/wildfly/src/main/java/hello/HelloController.java
@@ -0,0 +1,14 @@
+package hello;
+
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+@RestController
+public class HelloController {
+    
+    @RequestMapping("/")
+    public String index() {
+        return "Greetings from Spring Boot!";
+    }
+    
+}