Squashed commit of the following: (#10709)

commit 2347e8b21b
Author: ashleyfrieze <ashley@incredible.org.uk>
Date:   Tue Apr 27 21:40:33 2021 +0100

    Minor tweak to pom

commit 0497a9e3e8
Merge: a7cf36704b 58c06a67e3
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Mon Apr 26 20:27:13 2021 +0200

    Merge branch 'master' into feature/BAEL-4502-compile-time-const

commit a7cf36704b
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Mon Apr 26 20:25:47 2021 +0200

    BASE-4502: Update POM

commit 86bfe45c48
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sun Apr 25 20:32:35 2021 +0200

    BASE-4502: Revert POM changes and comment out JDK9+ code

commit b538d1cc19
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sun Apr 25 16:42:47 2021 +0200

    BASE-4502: Change parent

commit f608783de5
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sun Apr 25 16:38:00 2021 +0200

    BASE-4502: Maven compiler version

commit f15f2b8447
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sun Apr 25 16:13:05 2021 +0200

    BASE-4502: Compile to Java 11

commit 79e780667c
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sat Apr 24 08:53:53 2021 +0200

    BASE-4502: wrong case

commit fca2515c41
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sat Apr 10 11:32:59 2021 +0200

    BASE-4502: Add space

commit 0407a1e409
Merge: 54f11d5f05 5621594056
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sat Apr 10 11:24:57 2021 +0200

    Merge remote-tracking branch 'origin/feature/BAEL-4502-compile-time-const' into feature/BAEL-4502-compile-time-const

    # Conflicts:
    #	core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/ClassConstants.java
    #	core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/CompileTimeVariables.java

commit 54f11d5f05
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sat Apr 10 11:23:12 2021 +0200

    BASE-4502: PR comments and annotation example

commit 5621594056
Author: daniel.strmecki <daniel.strmecki@ecx.io>
Date:   Sun Apr 4 12:43:17 2021 +0200

    BAEL-4502: Remove unused examples

commit b11077e79b
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sat Apr 3 11:14:29 2021 +0200

    BASE-4502: Update examples

commit 9fea197cd6
Merge: f6e1f2fc46 b45902f460
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sun Mar 28 17:41:46 2021 +0200

    Merge branch 'master' into feature/BAEL-4502-compile-time-const

commit f6e1f2fc46
Author: Daniel Strmecki <daniel.strmecki@gmail.com>
Date:   Sun Mar 28 17:40:31 2021 +0200

    BASE-4502: Compile time examples

core-java-modules/core-java-lang-4/pom.xml

@@ -39,5 +39,4 @@
             </resource>
         </resources>
     </build>
-      
-</project>
+</project>

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/Annotations.java

@@ -0,0 +1,11 @@
+package com.baeldung.compiletimeconstants;
+
+public class Annotations {
+
+    private final String deprecatedDate = "20-02-14";
+    private final String deprecatedTime = "22:00";
+
+    //@Deprecated(since = deprecatedDate + " " + deprecatedTime) //TODO: Required JDK 9+
+    public void deprecatedMethod() {}
+
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/ClassConstants.java

@@ -0,0 +1,19 @@
+package com.baeldung.compiletimeconstants;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class ClassConstants {
+
+    public static final int MAXIMUM_NUMBER_OF_USERS = 10;
+    public static final String DEFAULT_USERNAME = "unknown";
+
+    public static final Logger log = LoggerFactory.getLogger(ClassConstants.class);
+    public static final List<String> contributorGroups = Arrays.asList("contributor", "author");
+
+    public static final int MAXIMUM_NUMBER_OF_GUESTS = MAXIMUM_NUMBER_OF_USERS * 10;
+
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/CompileTimeVariables.java

@@ -0,0 +1,21 @@
+package com.baeldung.compiletimeconstants;
+
+import java.io.PrintWriter;
+
+public class CompileTimeVariables {
+
+    public final String errorMessage = ClassConstants.DEFAULT_USERNAME + " not allowed here.";
+    public final int maximumLoginAttempts = 5;
+
+    public static void main(String[] args) {
+        PrintWriter printWriter = System.console().writer();
+        printWriter.println(ClassConstants.DEFAULT_USERNAME);
+
+        CompileTimeVariables instance = new CompileTimeVariables();
+        printWriter.println(instance.maximumLoginAttempts);
+
+        final String username = "baeldung" + "-" + "user";
+        printWriter.println(username);
+    }
+
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/RuntimeVariables.java

@@ -0,0 +1,16 @@
+package com.baeldung.compiletimeconstants;
+
+import java.io.Console;
+public class RuntimeVariables {
+
+    public static void main(String[] args) {
+        Console console = System.console();
+
+        final String input = console.readLine();
+        console.writer().println(input);
+
+        final double random = Math.random();
+        console.writer().println("Number: " + random);
+    }
+
+}

core-java-modules/core-java-lang-4/src/main/java/com/baeldung/compiletimeconstants/SwitchStatement.java

@@ -0,0 +1,17 @@
+package com.baeldung.compiletimeconstants;
+
+public class SwitchStatement {
+
+    private static final String VALUE_ONE = "value-one";
+
+    public static void main(String[] args) {
+        final String valueTwo = "value" + "-" + "two";
+        switch (args[0]) {
+            case VALUE_ONE:
+                break;
+            case valueTwo:
+                break;
+        }
+    }
+
+}