Merge pull request #14485 from edizor/master

Update README

core-java-modules/core-java-collections-maps-6/README.md

@@ -3,3 +3,5 @@
 - [Convert Hashmap to JSON Object in Java](https://www.baeldung.com/java-convert-hashmap-to-json-object)
 - [Converting Map<String, Object> to Map<String, String> in Java](https://www.baeldung.com/java-converting-map-string-object-to-string-string)
 - [Converting Object To Map in Java](https://www.baeldung.com/java-convert-object-to-map)
+- [Difference Between Map.clear() and Instantiating a New Map](https://www.baeldung.com/java-map-clear-vs-new-map)
+- [Converting JsonNode Object to Map](https://www.baeldung.com/jackson-jsonnode-map)

core-java-modules/core-java-concurrency-basic-3/README.md

@@ -9,4 +9,5 @@ This module contains articles about basic Java concurrency.
 - [Is CompletableFuture Non-blocking?](https://www.baeldung.com/java-completablefuture-non-blocking)
 - [Returning a Value After Finishing Thread’s Job in Java](https://www.baeldung.com/java-return-value-after-thread-finish)
 - [CompletableFuture and ThreadPool in Java](https://www.baeldung.com/java-completablefuture-threadpool)
+- [CompletableFuture allOf().join() vs. CompletableFuture.join()](https://www.baeldung.com/java-completablefuture-allof-join)
 - [[<-- Prev]](../core-java-concurrency-basic-2)

core-java-modules/core-java-concurrency-basic/README.md

@@ -10,4 +10,5 @@ This module contains articles about basic Java concurrency
 - [ExecutorService – Waiting for Threads to Finish](https://www.baeldung.com/java-executor-wait-for-threads)
 - [Runnable vs. Callable in Java](https://www.baeldung.com/java-runnable-callable)
 - [What Is Thread-Safety and How to Achieve It?](https://www.baeldung.com/java-thread-safety)
+- [How to Get Notified When a Task Completes in Java Executors](https://www.baeldung.com/java-executors-task-completed-notification)
 - [[Next -->]](/core-java-modules/core-java-concurrency-basic-2)

core-java-modules/core-java-lang-6/README.md

@@ -5,3 +5,4 @@ This module contains articles about core features in the Java language
 ### Relevant Articles:
 
 - [Convert One Enum to Another Enum in Java](https://www.baeldung.com/java-convert-enums)
+- [What Is the Maximum Depth of the Java Call Stack?](https://www.baeldung.com/java-call-stack-max-depth)

core-java-modules/core-java-string-operations-6/README.md

@@ -8,3 +8,4 @@
 - [Compact Strings in Java 9](https://www.baeldung.com/java-9-compact-string)
 - [Split a String Into Digit and Non-Digit Substrings](https://www.baeldung.com/java-split-string-digits-letters)
 - [Check if a String Contains Non-Alphanumeric Characters](https://www.baeldung.com/java-string-test-special-characters)
+- [Check if a String Has All Unique Characters in Java](https://www.baeldung.com/java-check-string-all-unique-chars)

jeromq/README.md

@@ -0,0 +1,2 @@
+## Relevant Articles
+- [Introduction to JeroMQ](https://www.baeldung.com/java-jeromq-zeromq)

json-modules/gson-2/README.md

@@ -4,4 +4,5 @@ This module contains articles about Gson
 
 ### Relevant Articles: 
 - [Solving Gson Parsing Errors](https://www.baeldung.com/gson-parsing-errors)
+- [Difference between Gson @Expose and @SerializedName](https://www.baeldung.com/gson-expose-vs-serializedname)
 

persistence-modules/spring-data-rest-2/README.md

@@ -7,6 +7,7 @@ This module contains articles about Spring Data REST
 - [Spring Data Web Support](https://www.baeldung.com/spring-data-web-support)
 - [Spring REST and HAL Browser](https://www.baeldung.com/spring-rest-hal)
 - [Spring Data Rest – Serializing the Entity ID](https://www.baeldung.com/spring-data-rest-serialize-entity-id)
+- [Consuming Page Entity Response From RestTemplate](https://www.baeldung.com/resttemplate-page-entity-response)
 
 ### The Course
 The "REST With Spring" Classes: http://bit.ly/restwithspring

testing-modules/testing-libraries-2/README.md

@@ -5,3 +5,4 @@
 - [Code Coverage with SonarQube and JaCoCo](https://www.baeldung.com/sonarqube-jacoco-code-coverage)
 - [Exclusions from Jacoco Report](https://www.baeldung.com/jacoco-report-exclude)
 - [Gray Box Testing Using the OAT Technique](https://www.baeldung.com/java-gray-box-orthogonal-array-testing)
+- [Unit Testing of System.in With JUnit](https://www.baeldung.com/java-junit-testing-system-in)