diff --git a/algorithms-miscellaneous-6/README.md b/algorithms-miscellaneous-6/README.md
index 22ee51530f..6ddae75f43 100644
--- a/algorithms-miscellaneous-6/README.md
+++ b/algorithms-miscellaneous-6/README.md
@@ -7,4 +7,6 @@
- [Efficiently Merge Sorted Java Sequences](https://www.baeldung.com/java-merge-sorted-sequences)
- [Introduction to Greedy Algorithms with Java](https://www.baeldung.com/java-greedy-algorithms)
- [The Caesar Cipher in Java](https://www.baeldung.com/java-caesar-cipher)
+- [Implementing a 2048 Solver in Java](https://www.baeldung.com/2048-java-solver)
+- [Finding Top K Elements in an Array](https://www.baeldung.com/java-array-top-elements)
- More articles: [[<-- prev]](/../algorithms-miscellaneous-5)
diff --git a/apache-shiro/README.md b/apache-shiro/README.md
index ed63c569da..3a0088072f 100644
--- a/apache-shiro/README.md
+++ b/apache-shiro/README.md
@@ -6,4 +6,4 @@ This module contains articles about Apache Shiro
- [Introduction to Apache Shiro](https://www.baeldung.com/apache-shiro)
- [Permissions-Based Access Control with Apache Shiro](https://www.baeldung.com/apache-shiro-access-control)
-
+- [Spring Security vs Apache Shiro](https://www.baeldung.com/spring-security-vs-apache-shiro)
diff --git a/core-groovy/README.md b/core-groovy/README.md
index f852b3ccf2..70e8d262ce 100644
--- a/core-groovy/README.md
+++ b/core-groovy/README.md
@@ -13,4 +13,5 @@ This module contains articles about core Groovy concepts
- [Converting a String to a Date in Groovy](https://www.baeldung.com/groovy-string-to-date)
- [Guide to I/O in Groovy](https://www.baeldung.com/groovy-io)
- [Convert String to Integer in Groovy](https://www.baeldung.com/groovy-convert-string-to-integer)
+- [Groovy Variable Scope](https://www.baeldung.com/groovy/variable-scope)
- [[More -->]](/core-groovy-2)
diff --git a/core-java-modules/core-java-11/README.md b/core-java-modules/core-java-11/README.md
index 70e2e66737..a3601c8339 100644
--- a/core-java-modules/core-java-11/README.md
+++ b/core-java-modules/core-java-11/README.md
@@ -8,7 +8,7 @@ This module contains articles about Java 11 core features
- [Java 11 Local Variable Syntax for Lambda Parameters](https://www.baeldung.com/java-var-lambda-params)
- [Java 11 String API Additions](https://www.baeldung.com/java-11-string-api)
- [Java 11 Nest Based Access Control](https://www.baeldung.com/java-nest-based-access-control)
-- [Exploring the New HTTP Client in Java 9 and 11](https://www.baeldung.com/java-9-http-client)
+- [Exploring the New HTTP Client in Java](https://www.baeldung.com/java-9-http-client)
- [An Introduction to Epsilon GC: A No-Op Experimental Garbage Collector](https://www.baeldung.com/jvm-epsilon-gc-garbage-collector)
- [Guide to jlink](https://www.baeldung.com/jlink)
- [Negate a Predicate Method Reference with Java 11](https://www.baeldung.com/java-negate-predicate-method-reference)
diff --git a/core-java-modules/core-java-9-new-features/README.md b/core-java-modules/core-java-9-new-features/README.md
index c2ef63a530..d10d0aad2d 100644
--- a/core-java-modules/core-java-9-new-features/README.md
+++ b/core-java-modules/core-java-9-new-features/README.md
@@ -13,3 +13,4 @@ This module contains articles about core Java features that have been introduced
- [Java 9 Platform Logging API](https://www.baeldung.com/java-9-logging-api)
- [Java 9 Reactive Streams](https://www.baeldung.com/java-9-reactive-streams)
- [Multi-Release JAR Files with Maven](https://www.baeldung.com/maven-multi-release-jars)
+- [The Difference between RxJava API and the Java 9 Flow API](https://www.baeldung.com/rxjava-vs-java-flow-api)
diff --git a/core-java-modules/core-java-9/README.md b/core-java-modules/core-java-9/README.md
index 0a9bf76ac4..cab02369cc 100644
--- a/core-java-modules/core-java-9/README.md
+++ b/core-java-modules/core-java-9/README.md
@@ -9,3 +9,4 @@ This module contains articles about Java 9 core features
- [Iterate Through a Range of Dates in Java](https://www.baeldung.com/java-iterate-date-range)
- [Initialize a HashMap in Java](https://www.baeldung.com/java-initialize-hashmap)
- [Immutable ArrayList in Java](https://www.baeldung.com/java-immutable-list)
+- [Easy Ways to Write a Java InputStream to an OutputStream](https://www.baeldung.com/java-inputstream-to-outputstream)
diff --git a/core-java-modules/core-java-arrays-guides/README.md b/core-java-modules/core-java-arrays-guides/README.md
index 56c0c716d8..621443e4a9 100644
--- a/core-java-modules/core-java-arrays-guides/README.md
+++ b/core-java-modules/core-java-arrays-guides/README.md
@@ -5,4 +5,4 @@ This module contains complete guides about arrays in Java
### Relevant Articles:
- [Arrays in Java: A Reference Guide](https://www.baeldung.com/java-arrays-guide)
- [Guide to the java.util.Arrays Class](https://www.baeldung.com/java-util-arrays)
-- [What is [Ljava.lang.Object;?]](https://www.baeldung.com/java-tostring-array)
+- [What is \[Ljava.lang.Object;?](https://www.baeldung.com/java-tostring-array)
diff --git a/core-java-modules/core-java-collections-3/README.md b/core-java-modules/core-java-collections-3/README.md
index fb983d9abc..4349ef6be3 100644
--- a/core-java-modules/core-java-collections-3/README.md
+++ b/core-java-modules/core-java-collections-3/README.md
@@ -3,6 +3,7 @@
## Core Java Collections Cookbooks and Examples
### Relevant Articles:
+
- [Time Comparison of Arrays.sort(Object[]) and Arrays.sort(int[])](https://www.baeldung.com/arrays-sortobject-vs-sortint)
- [Java ArrayList vs Vector](https://www.baeldung.com/java-arraylist-vs-vector)
- [Differences Between HashMap and Hashtable](https://www.baeldung.com/hashmap-hashtable-differences)
@@ -10,3 +11,4 @@
- [Performance of contains() in a HashSet vs ArrayList](https://www.baeldung.com/java-hashset-arraylist-contains-performance)
- [Fail-Safe Iterator vs Fail-Fast Iterator](https://www.baeldung.com/java-fail-safe-vs-fail-fast-iterator)
- [Quick Guide to the Java Stack](https://www.baeldung.com/java-stack)
+- [Convert an Array of Primitives to a List](https://www.baeldung.com/java-primitive-array-to-list)
diff --git a/core-java-modules/core-java-concurrency-advanced-3/README.md b/core-java-modules/core-java-concurrency-advanced-3/README.md
index 8858760981..7d98e462d7 100644
--- a/core-java-modules/core-java-concurrency-advanced-3/README.md
+++ b/core-java-modules/core-java-concurrency-advanced-3/README.md
@@ -15,4 +15,5 @@ This module contains articles about advanced topics about multithreading with co
- [The ABA Problem in Concurrency](https://www.baeldung.com/cs/aba-concurrency)
- [Introduction to Lock-Free Data Structures](https://www.baeldung.com/lock-free-programming)
- [Introduction to Exchanger in Java](https://www.baeldung.com/java-exchanger)
+- [Why Not To Start A Thread In The Constructor?](https://www.baeldung.com/java-thread-constructor)
- [[<-- previous]](/core-java-modules/core-java-concurrency-advanced-2)
diff --git a/core-java-modules/core-java-concurrency-basic-2/README.md b/core-java-modules/core-java-concurrency-basic-2/README.md
index c7143baf36..a8daf14ea9 100644
--- a/core-java-modules/core-java-concurrency-basic-2/README.md
+++ b/core-java-modules/core-java-concurrency-basic-2/README.md
@@ -3,10 +3,12 @@
This module contains articles about basic Java concurrency
### Relevant Articles:
+
- [How to Delay Code Execution in Java](https://www.baeldung.com/java-delay-code-execution)
- [wait and notify() Methods in Java](https://www.baeldung.com/java-wait-notify)
- [Difference Between Wait and Sleep in Java](https://www.baeldung.com/java-wait-and-sleep)
- [Guide to the Synchronized Keyword in Java](https://www.baeldung.com/java-synchronized)
- [Life Cycle of a Thread in Java](https://www.baeldung.com/java-thread-lifecycle)
- [Guide to AtomicMarkableReference](https://www.baeldung.com/java-atomicmarkablereference)
+- [Why are Local Variables Thread-Safe in Java](https://www.baeldung.com/java-local-variables-thread-safe)
- [[<-- Prev]](/core-java-modules/core-java-concurrency-basic)
diff --git a/core-java-modules/core-java-console/src/main/java/com/baeldung/consoleout/ConsoleAndOut.java b/core-java-modules/core-java-console/src/main/java/com/baeldung/consoleout/ConsoleAndOut.java
new file mode 100644
index 0000000000..082a5219c9
--- /dev/null
+++ b/core-java-modules/core-java-console/src/main/java/com/baeldung/consoleout/ConsoleAndOut.java
@@ -0,0 +1,31 @@
+package com.baeldung.consoleout;
+
+import java.io.Console;
+
+public class ConsoleAndOut {
+ public static void main(String[] args) {
+ try {
+ printConsoleObject();
+ readPasswordFromConsole();
+ } catch (Exception ex) {
+ // Eating NullPointerExcpetion which will occur when this
+ // program will be run from mediums other than console
+ }
+ printSysOut();
+ }
+
+ static void printConsoleObject() {
+ Console console = System.console();
+ console.writer().print(console);
+ }
+
+ static void readPasswordFromConsole() {
+ Console console = System.console();
+ char[] password = console.readPassword("Enter password: ");
+ console.printf(String.valueOf(password));
+ }
+
+ static void printSysOut() {
+ System.out.println(System.out);
+ }
+}
diff --git a/core-java-modules/core-java-console/src/test/java/com/baeldung/consoleout/ConsoleAndOutUnitTest.java b/core-java-modules/core-java-console/src/test/java/com/baeldung/consoleout/ConsoleAndOutUnitTest.java
new file mode 100644
index 0000000000..619a65a1fc
--- /dev/null
+++ b/core-java-modules/core-java-console/src/test/java/com/baeldung/consoleout/ConsoleAndOutUnitTest.java
@@ -0,0 +1,27 @@
+package com.baeldung.consoleout;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.junit.jupiter.api.Test;
+
+class ConsoleAndOutUnitTest {
+
+ @Test
+ void whenRetreivingConsole_thenPrintConsoleObject() {
+ assertThrows(NullPointerException.class, () -> {
+ ConsoleAndOut.printConsoleObject();
+ });
+ }
+
+ @Test
+ void whenReadingPassword_thenReadPassword() {
+ assertThrows(NullPointerException.class, () -> {
+ ConsoleAndOut.readPasswordFromConsole();
+ });
+ }
+
+ @Test
+ void whenRetrievingSysOut_thenPrintSysOutObject() {
+ ConsoleAndOut.printSysOut();
+ }
+}
diff --git a/core-java-modules/core-java-date-operations-2/README.md b/core-java-modules/core-java-date-operations-2/README.md
index 6dc1302d99..557e4c3517 100644
--- a/core-java-modules/core-java-date-operations-2/README.md
+++ b/core-java-modules/core-java-date-operations-2/README.md
@@ -2,6 +2,7 @@
This module contains articles about date operations in Java.
### Relevant Articles:
+
- [Get the Current Date Prior to Java 8](https://www.baeldung.com/java-get-the-current-date-legacy)
- [Skipping Weekends While Adding Days to LocalDate in Java 8](https://www.baeldung.com/java-localdate-add-days-skip-weekends)
- [Checking If Two Java Dates Are on the Same Day](https://www.baeldung.com/java-check-two-dates-on-same-day)
@@ -9,4 +10,5 @@ This module contains articles about date operations in Java.
- [How to Set the JVM Time Zone](https://www.baeldung.com/java-jvm-time-zone)
- [How to determine day of week by passing specific date in Java?](https://www.baeldung.com/java-get-day-of-week)
- [Finding Leap Years in Java](https://www.baeldung.com/java-leap-year)
+- [Getting the Week Number From Any Date](https://www.baeldung.com/java-get-week-number)
- [[<-- Prev]](/core-java-modules/core-java-date-operations-1)
diff --git a/core-java-modules/core-java-exceptions-2/README.md b/core-java-modules/core-java-exceptions-2/README.md
index 46ffd490be..e6441c2c12 100644
--- a/core-java-modules/core-java-exceptions-2/README.md
+++ b/core-java-modules/core-java-exceptions-2/README.md
@@ -12,3 +12,5 @@ This module contains articles about core java exceptions
- [Java – Try with Resources](https://www.baeldung.com/java-try-with-resources)
- [Java Global Exception Handler](https://www.baeldung.com/java-global-exception-handler)
- [How to Find an Exception’s Root Cause in Java](https://www.baeldung.com/java-exception-root-cause)
+- [Java IOException “Too many open files”](https://www.baeldung.com/java-too-many-open-files)
+- [When Does Java Throw the ExceptionInInitializerError?](https://www.baeldung.com/java-exceptionininitializererror)
diff --git a/core-java-modules/core-java-io-3/README.md b/core-java-modules/core-java-io-3/README.md
index 39752346d3..61a040c1ce 100644
--- a/core-java-modules/core-java-io-3/README.md
+++ b/core-java-modules/core-java-io-3/README.md
@@ -3,5 +3,7 @@
This module contains articles about core Java input and output (IO)
### Relevant Articles:
+
- [Java – Create a File](https://www.baeldung.com/java-how-to-create-a-file)
+- [Check If a Directory Is Empty in Java](https://www.baeldung.com/java-check-empty-directory)
- [[<-- Prev]](/core-java-modules/core-java-io-2)
diff --git a/core-java-modules/core-java-io-3/pom.xml b/core-java-modules/core-java-io-3/pom.xml
index cb341ca2ae..cc4dca5fa5 100644
--- a/core-java-modules/core-java-io-3/pom.xml
+++ b/core-java-modules/core-java-io-3/pom.xml
@@ -46,41 +46,14 @@
${assertj.version}test
-
-
- com.github.tomakehurst
- wiremock
- ${wiremock.version}
- test
-
- core-java-io-3
-
-
- src/main/resources
- true
-
-
-
-
- org.apache.maven.plugins
- maven-javadoc-plugin
- ${maven-javadoc-plugin.version}
-
- ${maven.compiler.source}
- ${maven.compiler.target}
-
-
- 3.6.1
- 3.0.0-M1
- 2.26.3
\ No newline at end of file
diff --git a/core-java-modules/core-java-io-3/src/test/java/com/baeldung/emptiness/DirectoryEmptinessUnitTest.java b/core-java-modules/core-java-io-3/src/test/java/com/baeldung/emptiness/DirectoryEmptinessUnitTest.java
new file mode 100644
index 0000000000..a44aea1383
--- /dev/null
+++ b/core-java-modules/core-java-io-3/src/test/java/com/baeldung/emptiness/DirectoryEmptinessUnitTest.java
@@ -0,0 +1,63 @@
+package com.baeldung.emptiness;
+
+import org.junit.Test;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class DirectoryEmptinessUnitTest {
+
+ @Test
+ public void givenPath_whenInvalid_thenReturnsFalse() throws IOException {
+ assertThat(isEmpty(Paths.get("invalid-addr"))).isFalse();
+ }
+
+ @Test
+ public void givenPath_whenNotDirectory_thenReturnsFalse() throws IOException {
+ Path aFile = Paths.get(getClass().getResource("/notDir.txt").getPath());
+ assertThat(isEmpty(aFile)).isFalse();
+ }
+
+ @Test
+ public void givenPath_whenNotEmptyDir_thenReturnsFalse() throws IOException {
+ Path currentDir = new File("").toPath().toAbsolutePath();
+ assertThat(isEmpty(currentDir)).isFalse();
+ }
+
+ @Test
+ public void givenPath_whenIsEmpty_thenReturnsTrue() throws Exception {
+ Path path = Files.createTempDirectory("baeldung-empty");
+ assertThat(isEmpty(path)).isTrue();
+ }
+
+ private static boolean isEmpty(Path path) throws IOException {
+ if (Files.isDirectory(path)) {
+ try (DirectoryStream directory = Files.newDirectoryStream(path)) {
+ return !directory.iterator().hasNext();
+ }
+ }
+
+ return false;
+ }
+
+ private static boolean isEmpty2(Path path) throws IOException {
+ if (Files.isDirectory(path)) {
+ try (Stream entries = Files.list(path)) {
+ return !entries.findFirst().isPresent();
+ }
+ }
+
+ return false;
+ }
+
+ private static boolean isEmptyInefficient(Path path) {
+ return path.toFile().listFiles().length == 0;
+ }
+}
diff --git a/core-java-modules/core-java-io-3/src/test/resources/notDir.txt b/core-java-modules/core-java-io-3/src/test/resources/notDir.txt
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/core-java-modules/core-java-jvm-2/README.md b/core-java-modules/core-java-jvm-2/README.md
index 1aa69e7e63..7206a9eef7 100644
--- a/core-java-modules/core-java-jvm-2/README.md
+++ b/core-java-modules/core-java-jvm-2/README.md
@@ -8,4 +8,6 @@ This module contains articles about working with the Java Virtual Machine (JVM).
- [Measuring Object Sizes in the JVM](https://www.baeldung.com/jvm-measuring-object-sizes)
- [Adding Shutdown Hooks for JVM Applications](https://www.baeldung.com/jvm-shutdown-hooks)
- [boolean and boolean[] Memory Layout in the JVM](https://www.baeldung.com/jvm-boolean-memory-layout)
-- More articles: [[<-- prev]](/core-java-modules/core-java-jvm)
\ No newline at end of file
+- [Where Is the Array Length Stored in JVM?](https://www.baeldung.com/java-jvm-array-length)
+- [Memory Address of Objects in Java](https://www.baeldung.com/java-object-memory-address)
+- More articles: [[<-- prev]](/core-java-modules/core-java-jvm)
diff --git a/core-java-modules/core-java-lang-3/README.md b/core-java-modules/core-java-lang-3/README.md
index f496b74bfb..9ce49da868 100644
--- a/core-java-modules/core-java-lang-3/README.md
+++ b/core-java-modules/core-java-lang-3/README.md
@@ -2,4 +2,6 @@
This module contains articles about core features in the Java language
+- [Class.isInstance vs Class.isAssignableFrom](https://www.baeldung.com/java-isinstance-isassignablefrom)
+- [Converting a Java String Into a Boolean](https://www.baeldung.com/java-string-to-boolean)
- [[<-- Prev]](/core-java-modules/core-java-lang-2)
diff --git a/core-java-modules/core-java-lang-oop-methods/README.md b/core-java-modules/core-java-lang-oop-methods/README.md
index fa474c9795..afceaded9a 100644
--- a/core-java-modules/core-java-lang-oop-methods/README.md
+++ b/core-java-modules/core-java-lang-oop-methods/README.md
@@ -3,7 +3,9 @@
This module contains articles about methods in Java
### Relevant Articles:
+
- [Methods in Java](https://www.baeldung.com/java-methods)
- [Method Overloading and Overriding in Java](https://www.baeldung.com/java-method-overload-override)
- [Java equals() and hashCode() Contracts](https://www.baeldung.com/java-equals-hashcode-contracts)
- [Guide to hashCode() in Java](https://www.baeldung.com/java-hashcode)
+- [The Covariant Return Type in Java](https://www.baeldung.com/java-covariant-return-type)
diff --git a/core-java-modules/core-java-networking-2/README.md b/core-java-modules/core-java-networking-2/README.md
index 662d97252e..dbda8bdc7c 100644
--- a/core-java-modules/core-java-networking-2/README.md
+++ b/core-java-modules/core-java-networking-2/README.md
@@ -12,4 +12,5 @@ This module contains articles about networking in Java
- [Authentication with HttpUrlConnection](https://www.baeldung.com/java-http-url-connection)
- [Download a File from an URL in Java](https://www.baeldung.com/java-download-file)
- [Handling java.net.ConnectException](https://www.baeldung.com/java-net-connectexception)
+- [Getting MAC addresses in Java](https://www.baeldung.com/java-mac-address)
- [[<-- Prev]](/core-java-modules/core-java-networking)
diff --git a/core-java-modules/core-java-reflection-2/README.md b/core-java-modules/core-java-reflection-2/README.md
new file mode 100644
index 0000000000..342fbd73bd
--- /dev/null
+++ b/core-java-modules/core-java-reflection-2/README.md
@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Reading the Value of ‘private’ Fields from a Different Class in Java](https://www.baeldung.com/java-reflection-read-private-field-value)
diff --git a/core-java-modules/core-java-reflection/README.MD b/core-java-modules/core-java-reflection/README.MD
index d6b3a02e6a..5d8c54414b 100644
--- a/core-java-modules/core-java-reflection/README.MD
+++ b/core-java-modules/core-java-reflection/README.MD
@@ -8,5 +8,4 @@
- [Changing Annotation Parameters At Runtime](http://www.baeldung.com/java-reflection-change-annotation-params)
- [Dynamic Proxies in Java](http://www.baeldung.com/java-dynamic-proxies)
- [What Causes java.lang.reflect.InvocationTargetException?](https://www.baeldung.com/java-lang-reflect-invocationtargetexception)
-- [How to Find all Getters Returning Null](http://www.baeldung.com/java-getters-returning-null)
- [How to Get a Name of a Method Being Executed?](http://www.baeldung.com/java-name-of-executing-method)
diff --git a/core-java-modules/core-java-regex/README.md b/core-java-modules/core-java-regex/README.md
index 8830af2c2d..ad8ba1e4ae 100644
--- a/core-java-modules/core-java-regex/README.md
+++ b/core-java-modules/core-java-regex/README.md
@@ -3,6 +3,7 @@
## Core Java 8 Cookbooks and Examples
### Relevant Articles:
+
- [An Overview of Regular Expressions Performance in Java](https://www.baeldung.com/java-regex-performance)
- [A Guide To Java Regular Expressions API](http://www.baeldung.com/regular-expressions-java)
- [Guide to Escaping Characters in Java RegExps](http://www.baeldung.com/java-regexp-escape-char)
@@ -11,3 +12,4 @@
- [How to Use Regular Expressions to Replace Tokens in Strings](https://www.baeldung.com/java-regex-token-replacement)
- [Regular Expressions \s and \s+ in Java](https://www.baeldung.com/java-regex-s-splus)
- [Validate Phone Numbers With Java Regex](https://www.baeldung.com/java-regex-validate-phone-numbers)
+- [How to Count the Number of Matches for a Regex?](https://www.baeldung.com/java-count-regex-matches)
diff --git a/core-java-modules/core-java-security-2/README.md b/core-java-modules/core-java-security-2/README.md
index 24a821bd4d..ba8cce46a0 100644
--- a/core-java-modules/core-java-security-2/README.md
+++ b/core-java-modules/core-java-security-2/README.md
@@ -9,4 +9,5 @@ This module contains articles about core Java Security
- [Hashing a Password in Java](https://www.baeldung.com/java-password-hashing)
- [SHA-256 and SHA3-256 Hashing in Java](https://www.baeldung.com/sha-256-hashing-java)
- [Checksums in Java](https://www.baeldung.com/java-checksums)
+- [How to Read PEM File to Get Public and Private Keys](https://www.baeldung.com/java-read-pem-file-keys)
- More articles: [[<-- prev]](/core-java-modules/core-java-security)
diff --git a/core-java-modules/core-java-string-operations-3/README.md b/core-java-modules/core-java-string-operations-3/README.md
new file mode 100644
index 0000000000..4e46849c11
--- /dev/null
+++ b/core-java-modules/core-java-string-operations-3/README.md
@@ -0,0 +1,3 @@
+### Relevant Articles:
+
+- [Version Comparison in Java](https://www.baeldung.com/java-comparing-versions)
diff --git a/core-kotlin-modules/core-kotlin-collections/README.md b/core-kotlin-modules/core-kotlin-collections/README.md
index dcf2743577..2ebb748cba 100644
--- a/core-kotlin-modules/core-kotlin-collections/README.md
+++ b/core-kotlin-modules/core-kotlin-collections/README.md
@@ -3,6 +3,7 @@
This module contains articles about core Kotlin collections.
### Relevant articles:
+
- [Split a List Into Parts in Kotlin](https://www.baeldung.com/kotlin-split-list-into-parts)
- [Finding an Element in a List Using Kotlin](https://www.baeldung.com/kotlin-finding-element-in-list)
- [Overview of Kotlin Collections API](https://www.baeldung.com/kotlin-collections-api)
@@ -12,3 +13,4 @@ This module contains articles about core Kotlin collections.
- [Difference between fold and reduce in Kotlin](https://www.baeldung.com/kotlin/fold-vs-reduce)
- [Guide to Sorting in Kotlin](https://www.baeldung.com/kotlin-sort)
- [Working With Lists in Kotlin](https://www.baeldung.com/kotlin/lists)
+- [Iterating Collections by Index in Kotlin](https://www.baeldung.com/kotlin/iterating-collections-by-index)
diff --git a/core-kotlin-modules/core-kotlin-collections/src/main/kotlin/com/baeldung/index/IndexedIteration.kt b/core-kotlin-modules/core-kotlin-collections/src/main/kotlin/com/baeldung/index/IndexedIteration.kt
new file mode 100644
index 0000000000..07fb595ede
--- /dev/null
+++ b/core-kotlin-modules/core-kotlin-collections/src/main/kotlin/com/baeldung/index/IndexedIteration.kt
@@ -0,0 +1,33 @@
+package com.baeldung.index
+
+fun main() {
+
+ // Index only
+ val colors = listOf("Red", "Green", "Blue")
+ for (i in colors.indices) {
+ println(colors[i])
+ }
+
+ val colorArray = arrayOf("Red", "Green", "Blue")
+ for (i in colorArray.indices) {
+ println(colorArray[i])
+ }
+
+ (0 until colors.size).forEach { println(colors[it]) }
+ for (i in 0 until colors.size) {
+ println(colors[i])
+ }
+
+ // Index and Value
+ colors.forEachIndexed { i, v -> println("The value for index $i is $v") }
+ for (indexedValue in colors.withIndex()) {
+ println("The value for index ${indexedValue.index} is ${indexedValue.value}")
+ }
+
+ for ((i, v) in colors.withIndex()) {
+ println("The value for index $i is $v")
+ }
+
+ colors.filterIndexed { i, _ -> i % 2 == 0 }
+ colors.filterIndexed { _, v -> v == "RED" }
+}
diff --git a/core-kotlin-modules/core-kotlin-lang-oop-2/README.md b/core-kotlin-modules/core-kotlin-lang-oop-2/README.md
index 27536273dc..a62a25c01d 100644
--- a/core-kotlin-modules/core-kotlin-lang-oop-2/README.md
+++ b/core-kotlin-modules/core-kotlin-lang-oop-2/README.md
@@ -7,4 +7,5 @@ This module contains articles about Object-Oriented Programming in Kotlin
- [Generics in Kotlin](https://www.baeldung.com/kotlin-generics)
- [Delegated Properties in Kotlin](https://www.baeldung.com/kotlin-delegated-properties)
- [Delegation Pattern in Kotlin](https://www.baeldung.com/kotlin-delegation-pattern)
+- [Anonymous Inner Classes in Kotlin](https://www.baeldung.com/kotlin/anonymous-inner-classes)
- [[<-- Prev]](/core-kotlin-modules/core-kotlin-lang-oop)
diff --git a/core-kotlin-modules/core-kotlin-lang-oop-2/src/main/kotlin/com/baeldung/anonymous/Anonymous.kt b/core-kotlin-modules/core-kotlin-lang-oop-2/src/main/kotlin/com/baeldung/anonymous/Anonymous.kt
new file mode 100644
index 0000000000..ea471f5d00
--- /dev/null
+++ b/core-kotlin-modules/core-kotlin-lang-oop-2/src/main/kotlin/com/baeldung/anonymous/Anonymous.kt
@@ -0,0 +1,41 @@
+package com.baeldung.anonymous
+
+import java.io.Serializable
+import java.nio.channels.Channel
+
+fun main() {
+ val channel = object : Channel {
+ override fun isOpen() = false
+
+ override fun close() {
+ }
+ }
+
+ val maxEntries = 10
+ val lruCache = object : LinkedHashMap(10, 0.75f) {
+
+ override fun removeEldestEntry(eldest: MutableMap.MutableEntry?): Boolean {
+ return size > maxEntries
+ }
+ }
+
+ val map = object : LinkedHashMap() {
+ // omitted
+ }
+
+ val serializableChannel = object : Channel, Serializable {
+ override fun isOpen(): Boolean {
+ TODO("Not yet implemented")
+ }
+
+ override fun close() {
+ TODO("Not yet implemented")
+ }
+ }
+
+ val obj = object {
+ val question = "answer"
+ val answer = 42
+ }
+ println("The ${obj.question} is ${obj.answer}")
+}
\ No newline at end of file
diff --git a/data-structures/README.md b/data-structures/README.md
index e3436695ce..0a29bd8964 100644
--- a/data-structures/README.md
+++ b/data-structures/README.md
@@ -11,3 +11,4 @@ This module contains articles about data structures in Java
- [Introduction to Big Queue](https://www.baeldung.com/java-big-queue)
- [Guide to AVL Trees in Java](https://www.baeldung.com/java-avl-trees)
- [Graphs in Java](https://www.baeldung.com/java-graphs)
+- [Implementing a Ring Buffer in Java](https://www.baeldung.com/java-ring-buffer)
diff --git a/docker/docker-spring-boot/mvnw b/docker/docker-spring-boot/mvnw
new file mode 100755
index 0000000000..a16b5431b4
--- /dev/null
+++ b/docker/docker-spring-boot/mvnw
@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# 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
+#
+# https://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.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+# JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+# M2_HOME - location of maven2's installed home dir
+# MAVEN_OPTS - parameters passed to the Java VM when running Maven
+# e.g. to debug Maven itself, use
+# set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+# MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+ if [ -f /etc/mavenrc ] ; then
+ . /etc/mavenrc
+ fi
+
+ if [ -f "$HOME/.mavenrc" ] ; then
+ . "$HOME/.mavenrc"
+ fi
+
+fi
+
+# OS specific support. $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+ CYGWIN*) cygwin=true ;;
+ MINGW*) mingw=true;;
+ Darwin*) darwin=true
+ # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+ # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+ if [ -z "$JAVA_HOME" ]; then
+ if [ -x "/usr/libexec/java_home" ]; then
+ export JAVA_HOME="`/usr/libexec/java_home`"
+ else
+ export JAVA_HOME="/Library/Java/Home"
+ fi
+ fi
+ ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+ if [ -r /etc/gentoo-release ] ; then
+ JAVA_HOME=`java-config --jre-home`
+ fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+ ## resolve links - $0 may be a link to maven's home
+ PRG="$0"
+
+ # need this for relative symlinks
+ while [ -h "$PRG" ] ; do
+ ls=`ls -ld "$PRG"`
+ link=`expr "$ls" : '.*-> \(.*\)$'`
+ if expr "$link" : '/.*' > /dev/null; then
+ PRG="$link"
+ else
+ PRG="`dirname "$PRG"`/$link"
+ fi
+ done
+
+ saveddir=`pwd`
+
+ M2_HOME=`dirname "$PRG"`/..
+
+ # make it fully qualified
+ M2_HOME=`cd "$M2_HOME" && pwd`
+
+ cd "$saveddir"
+ # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME=`cygpath --unix "$M2_HOME"`
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+ [ -n "$CLASSPATH" ] &&
+ CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME="`(cd "$M2_HOME"; pwd)`"
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+ javaExecutable="`which javac`"
+ if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+ # readlink(1) is not available as standard on Solaris 10.
+ readLink=`which readlink`
+ if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+ if $darwin ; then
+ javaHome="`dirname \"$javaExecutable\"`"
+ javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+ else
+ javaExecutable="`readlink -f \"$javaExecutable\"`"
+ fi
+ javaHome="`dirname \"$javaExecutable\"`"
+ javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+ JAVA_HOME="$javaHome"
+ export JAVA_HOME
+ fi
+ fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+ if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ else
+ JAVACMD="`which java`"
+ fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+ echo "Error: JAVA_HOME is not defined correctly." >&2
+ echo " We cannot execute $JAVACMD" >&2
+ exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+ echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+ if [ -z "$1" ]
+ then
+ echo "Path not specified to find_maven_basedir"
+ return 1
+ fi
+
+ basedir="$1"
+ wdir="$1"
+ while [ "$wdir" != '/' ] ; do
+ if [ -d "$wdir"/.mvn ] ; then
+ basedir=$wdir
+ break
+ fi
+ # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+ if [ -d "${wdir}" ]; then
+ wdir=`cd "$wdir/.."; pwd`
+ fi
+ # end of workaround
+ done
+ echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+ if [ -f "$1" ]; then
+ echo "$(tr -s '\n' ' ' < "$1")"
+ fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+ exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found .mvn/wrapper/maven-wrapper.jar"
+ fi
+else
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+ fi
+ if [ -n "$MVNW_REPOURL" ]; then
+ jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ else
+ jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ fi
+ while IFS="=" read key value; do
+ case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+ esac
+ done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Downloading from: $jarUrl"
+ fi
+ wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+ if $cygwin; then
+ wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+ fi
+
+ if command -v wget > /dev/null; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found wget ... using wget"
+ fi
+ if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+ wget "$jarUrl" -O "$wrapperJarPath"
+ else
+ wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+ fi
+ elif command -v curl > /dev/null; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found curl ... using curl"
+ fi
+ if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+ curl -o "$wrapperJarPath" "$jarUrl" -f
+ else
+ curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+ fi
+
+ else
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Falling back to using Java to download"
+ fi
+ javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+ # For Cygwin, switch paths to Windows format before running javac
+ if $cygwin; then
+ javaClass=`cygpath --path --windows "$javaClass"`
+ fi
+ if [ -e "$javaClass" ]; then
+ if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo " - Compiling MavenWrapperDownloader.java ..."
+ fi
+ # Compiling the Java class
+ ("$JAVA_HOME/bin/javac" "$javaClass")
+ fi
+ if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+ # Running the downloader
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo " - Running MavenWrapperDownloader.java ..."
+ fi
+ ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+ fi
+ fi
+ fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+ echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME=`cygpath --path --windows "$M2_HOME"`
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+ [ -n "$CLASSPATH" ] &&
+ CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+ [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+ MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+ $MAVEN_OPTS \
+ -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+ "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+ ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"
diff --git a/docker/docker-spring-boot/mvnw.cmd b/docker/docker-spring-boot/mvnw.cmd
new file mode 100644
index 0000000000..c8d43372c9
--- /dev/null
+++ b/docker/docker-spring-boot/mvnw.cmd
@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements. See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership. The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License. You may obtain a copy of the License at
+@REM
+@REM https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied. See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on" echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+ IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Found %WRAPPER_JAR%
+ )
+) else (
+ if not "%MVNW_REPOURL%" == "" (
+ SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ )
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Couldn't find %WRAPPER_JAR%, downloading it ...
+ echo Downloading from: %DOWNLOAD_URL%
+ )
+
+ powershell -Command "&{"^
+ "$webclient = new-object System.Net.WebClient;"^
+ "if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+ "$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+ "}"^
+ "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+ "}"
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Finished downloading %WRAPPER_JAR%
+ )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%
diff --git a/docker/docker-spring-boot/pom.xml b/docker/docker-spring-boot/pom.xml
new file mode 100644
index 0000000000..b9c80bc43a
--- /dev/null
+++ b/docker/docker-spring-boot/pom.xml
@@ -0,0 +1,54 @@
+
+
+ 4.0.0
+
+ org.springframework.boot
+ spring-boot-starter-parent
+ 2.3.1.RELEASE
+
+
+ com.baeldung.docker
+ spring-boot-docker
+ 0.0.1-SNAPSHOT
+ spring-boot-docker
+ Demo project showing Spring Boot and Docker
+
+
+ 8
+
+
+
+
+ org.springframework.boot
+ spring-boot-starter-web
+
+
+
+ org.springframework.boot
+ spring-boot-starter-test
+ test
+
+
+ org.junit.vintage
+ junit-vintage-engine
+
+
+
+
+
+
+
+
+ org.springframework.boot
+ spring-boot-maven-plugin
+
+
+ true
+
+
+
+
+
+
+
diff --git a/docker/docker-spring-boot/src/main/docker/Dockerfile b/docker/docker-spring-boot/src/main/docker/Dockerfile
new file mode 100644
index 0000000000..fa147dd69b
--- /dev/null
+++ b/docker/docker-spring-boot/src/main/docker/Dockerfile
@@ -0,0 +1,15 @@
+# To build, run the following command from the top level project directory:
+#
+# docker build -f src/main/docker/Dockerfile .
+
+FROM adoptopenjdk:11-jre-hotspot as builder
+ARG JAR_FILE=target/*.jar
+COPY ${JAR_FILE} application.jar
+RUN java -Djarmode=layertools -jar application.jar extract
+
+FROM adoptopenjdk:11-jre-hotspot
+COPY --from=builder dependencies/ ./
+COPY --from=builder snapshot-dependencies/ ./
+COPY --from=builder spring-boot-loader/ ./
+COPY --from=builder application/ ./
+ENTRYPOINT ["java", "org.springframework.boot.loader.JarLauncher"]
\ No newline at end of file
diff --git a/docker/docker-spring-boot/src/main/java/com/baeldung/docker/DemoApplication.java b/docker/docker-spring-boot/src/main/java/com/baeldung/docker/DemoApplication.java
new file mode 100644
index 0000000000..e0c1d57e89
--- /dev/null
+++ b/docker/docker-spring-boot/src/main/java/com/baeldung/docker/DemoApplication.java
@@ -0,0 +1,13 @@
+package com.baeldung.docker;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class DemoApplication {
+
+ public static void main(String[] args) {
+ SpringApplication.run(DemoApplication.class, args);
+ }
+
+}
diff --git a/docker/docker-spring-boot/src/main/java/com/baeldung/docker/HelloController.java b/docker/docker-spring-boot/src/main/java/com/baeldung/docker/HelloController.java
new file mode 100644
index 0000000000..b463bb557f
--- /dev/null
+++ b/docker/docker-spring-boot/src/main/java/com/baeldung/docker/HelloController.java
@@ -0,0 +1,16 @@
+package com.baeldung.docker;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HelloController {
+
+ @GetMapping("/hello")
+ public ResponseEntity hello()
+ {
+ return ResponseEntity.ok("hello2 ");
+ }
+
+}
diff --git a/docker/docker-spring-boot/src/main/resources/application.properties b/docker/docker-spring-boot/src/main/resources/application.properties
new file mode 100644
index 0000000000..8b13789179
--- /dev/null
+++ b/docker/docker-spring-boot/src/main/resources/application.properties
@@ -0,0 +1 @@
+
diff --git a/gradle-5/README.md b/gradle-5/README.md
index 7c9aeff07e..e37c100534 100644
--- a/gradle-5/README.md
+++ b/gradle-5/README.md
@@ -1,3 +1,4 @@
### Relevant Articles:
- [Run a Java main Method Using Gradle](https://www.baeldung.com/gradle-run-java-main)
+- [Finding Unused Gradle Dependencies](https://www.baeldung.com/gradle-finding-unused-dependencies)
diff --git a/guava-2/README.md b/guava-2/README.md
index 634c17f0eb..32afc10916 100644
--- a/guava-2/README.md
+++ b/guava-2/README.md
@@ -3,5 +3,5 @@
This module contains articles a Google Guava
### Relevant Articles:
-- [Introduction to Guava Throwables](https://www.baeldung.com/guava-throwables)
+
- [Guava CharMatcher](https://www.baeldung.com/guava-string-charmatcher)
diff --git a/guava/README.md b/guava/README.md
index 720aba274d..24beca60c3 100644
--- a/guava/README.md
+++ b/guava/README.md
@@ -3,6 +3,7 @@
This module contains articles a Google Guava
### Relevant Articles:
+
- [Guava Functional Cookbook](https://www.baeldung.com/guava-functions-predicates)
- [Guide to Guava’s PreConditions](https://www.baeldung.com/guava-preconditions)
- [Introduction to Guava CacheLoader](https://www.baeldung.com/guava-cacheloader)
@@ -13,3 +14,4 @@ This module contains articles a Google Guava
- [Bloom Filter in Java using Guava](https://www.baeldung.com/guava-bloom-filter)
- [Quick Guide to the Guava RateLimiter](https://www.baeldung.com/guava-rate-limiter)
- [Guava Cache](https://www.baeldung.com/guava-cache)
+- [Introduction to Guava Throwables](https://www.baeldung.com/guava-throwables)
diff --git a/image-processing/README.md b/image-processing/README.md
index 50129bb994..eba23f83eb 100644
--- a/image-processing/README.md
+++ b/image-processing/README.md
@@ -6,3 +6,5 @@ This module contains articles about image processing.
- [Working with Images in Java](https://www.baeldung.com/java-images)
- [Intro to OpenCV with Java](https://www.baeldung.com/java-opencv)
- [Optical Character Recognition with Tesseract](https://www.baeldung.com/java-ocr-tesseract)
+- [How Can I Resize an Image Using Java?](https://www.baeldung.com/java-resize-image)
+- [Adding Text to an Image in Java](https://www.baeldung.com/java-add-text-to-image)
diff --git a/java-collections-conversions-2/src/main/java/com/baeldung/convertlisttomap/ListToMapConverter.java b/java-collections-conversions-2/src/main/java/com/baeldung/convertlisttomap/ListToMapConverter.java
new file mode 100644
index 0000000000..8450f54f9d
--- /dev/null
+++ b/java-collections-conversions-2/src/main/java/com/baeldung/convertlisttomap/ListToMapConverter.java
@@ -0,0 +1,70 @@
+package com.baeldung.convertlisttomap;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.BiConsumer;
+import java.util.function.BinaryOperator;
+import java.util.function.Function;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+
+/**
+ * Convert a string list to a map whose key is the string's length and value is the collection with same length.
+ * Give a list {"Baeldung", "is", "very", "cool"}.
+ * After conversion we'll get a map like:
+ * {8 : ["Baeldung"], 2 : ["is"], 4 : ["very", "cool"]}.
+ *
+ * @author leasy.zhang
+ *
+ */
+public class ListToMapConverter {
+
+ public Map> groupingByStringLength(List source,
+ Supplier