diff --git a/.idea/compiler.xml b/.idea/compiler.xml
index 8bcc66e377..83b2580807 100644
--- a/.idea/compiler.xml
+++ b/.idea/compiler.xml
@@ -2,6 +2,7 @@
 <project version="4">
   <component name="CompilerConfiguration">
     <annotationProcessing>
+      <profile default="true" name="Default" enabled="true" />
       <profile name="Maven default annotation processors profile" enabled="true">
         <sourceOutputDir name="target/generated-sources/annotations" />
         <sourceTestOutputDir name="target/generated-test-sources/test-annotations" />
@@ -21,18 +22,22 @@
         <module name="spring-data-jpa-repo-2" />
         <module name="core-java-streams" />
         <module name="core-java-io" />
-        <module name="java-collections-conversions" />
         <module name="core-java-8-2" />
         <module name="discourse" />
         <module name="spring-data-redis" />
         <module name="core-java" />
         <module name="core-java-collections-list-2" />
         <module name="core-java-collections-list-3" />
+        <module name="core-java-collections-conversions-2" />
         <module name="core-java-8" />
         <module name="core-java-collections-3" />
         <module name="core-java-collections-2" />
       </profile>
     </annotationProcessing>
+    <bytecodeTargetLevel>
+      <module name="java-collections-conversions" target="11" />
+      <module name="java-collections-conversions-2" target="11" />
+    </bytecodeTargetLevel>
   </component>
   <component name="JavacSettings">
     <option name="ADDITIONAL_OPTIONS_OVERRIDE">
diff --git a/.idea/encodings.xml b/.idea/encodings.xml
index 8a054a42e4..505d9aef73 100644
--- a/.idea/encodings.xml
+++ b/.idea/encodings.xml
@@ -13,6 +13,8 @@
     <file url="file://$PROJECT_DIR$/core-java-modules/core-java-collections-2/src/main/resources" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/core-java-modules/core-java-collections-3/src/main/java" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/core-java-modules/core-java-collections-3/src/main/resources" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/core-java-modules/core-java-collections-conversions-2/src/main/java" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/core-java-modules/core-java-collections-conversions-2/src/main/resources" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/core-java-modules/core-java-collections-conversions/src/main/java" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/core-java-modules/core-java-collections-conversions/src/main/resources" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/core-java-modules/core-java-collections-list-2/src/main/java" charset="UTF-8" />
diff --git a/core-java-modules/core-java-collections-conversions-2/README.md b/core-java-modules/core-java-collections-conversions-2/README.md
new file mode 100644
index 0000000000..00e4551bbd
--- /dev/null
+++ b/core-java-modules/core-java-collections-conversions-2/README.md
@@ -0,0 +1,14 @@
+## Java 集合（Collections）相关文章和实例
+
+本模块中的内容包含有 Java 集合（Collections）和数组（arrays）中进行转换。
+
+### 相关文章
+
+- [Java Array 和 String 的转换](https://www.ossez.com/t/java-array-string/13685)
+- [Mapping Lists with ModelMapper](https://www.baeldung.com/java-modelmapper-lists)
+- [Converting List to Map With a Custom Supplier](https://www.baeldung.com/list-to-map-supplier)
+- [Arrays.asList vs new ArrayList(Arrays.asList())](https://www.baeldung.com/java-arrays-aslist-vs-new-arraylist)
+- [Iterate Over a Set in Java](https://www.baeldung.com/java-iterate-set)
+- [Convert a List of Integers to a List of Strings](https://www.baeldung.com/java-convert-list-integers-to-list-strings)
+- [Combining Two Lists Into a Map in Java](https://www.baeldung.com/java-combine-two-lists-into-map)
+- More articles: [[<-- prev]](../core-java-collections-conversions)
diff --git a/java-collections-conversions-2/pom.xml b/core-java-modules/core-java-collections-conversions-2/pom.xml
similarity index 87%
rename from java-collections-conversions-2/pom.xml
rename to core-java-modules/core-java-collections-conversions-2/pom.xml
index 03d7164285..2e3480418a 100644
--- a/java-collections-conversions-2/pom.xml
+++ b/core-java-modules/core-java-collections-conversions-2/pom.xml
@@ -3,16 +3,16 @@
     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>java-collections-conversions-2</artifactId>
+    <artifactId>core-java-collections-conversions-2</artifactId>
     <version>0.1.0-SNAPSHOT</version>
-    <name>java-collections-conversions-2</name>
+    <name>core-java-collections-conversions-2</name>
     <packaging>jar</packaging>
 
     <parent>
-        <groupId>com.ossez</groupId>
-        <artifactId>parent-java</artifactId>
+        <groupId>com.ossez.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
         <version>0.0.2-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
+        <relativePath>../pom.xml</relativePath>
     </parent>
 
     <dependencies>
diff --git a/java-collections-conversions-2/src/main/java/com/ossez/convertlisttomap/ListToMapConverter.java b/core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/convertlisttomap/ListToMapConverter.java
similarity index 100%
rename from java-collections-conversions-2/src/main/java/com/ossez/convertlisttomap/ListToMapConverter.java
rename to core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/convertlisttomap/ListToMapConverter.java
diff --git a/java-collections-conversions-2/src/main/java/com/ossez/modelmapper/MapperUtil.java b/core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/MapperUtil.java
similarity index 100%
rename from java-collections-conversions-2/src/main/java/com/ossez/modelmapper/MapperUtil.java
rename to core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/MapperUtil.java
diff --git a/java-collections-conversions-2/src/main/java/com/ossez/modelmapper/User.java b/core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/User.java
similarity index 100%
rename from java-collections-conversions-2/src/main/java/com/ossez/modelmapper/User.java
rename to core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/User.java
diff --git a/java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserDTO.java b/core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserDTO.java
similarity index 100%
rename from java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserDTO.java
rename to core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserDTO.java
diff --git a/java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserList.java b/core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserList.java
similarity index 100%
rename from java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserList.java
rename to core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserList.java
diff --git a/java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserListDTO.java b/core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserListDTO.java
similarity index 100%
rename from java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserListDTO.java
rename to core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UserListDTO.java
diff --git a/java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UsersListConverter.java b/core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UsersListConverter.java
similarity index 100%
rename from java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UsersListConverter.java
rename to core-java-modules/core-java-collections-conversions-2/src/main/java/com/ossez/modelmapper/UsersListConverter.java
diff --git a/java-collections-conversions-2/src/test/java/com/ossez/arrayconversion/ArrayToListConversionUnitTest.java b/core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/arrayconversion/ArrayToListConversionUnitTest.java
similarity index 100%
rename from java-collections-conversions-2/src/test/java/com/ossez/arrayconversion/ArrayToListConversionUnitTest.java
rename to core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/arrayconversion/ArrayToListConversionUnitTest.java
diff --git a/java-collections-conversions-2/src/test/java/com/ossez/convertarraytostring/ArrayToStringUnitTest.java b/core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/convertarraytostring/ArrayToStringUnitTest.java
similarity index 100%
rename from java-collections-conversions-2/src/test/java/com/ossez/convertarraytostring/ArrayToStringUnitTest.java
rename to core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/convertarraytostring/ArrayToStringUnitTest.java
diff --git a/java-collections-conversions-2/src/test/java/com/ossez/convertlisttomap/ListToMapUnitTest.java b/core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/convertlisttomap/ListToMapUnitTest.java
similarity index 100%
rename from java-collections-conversions-2/src/test/java/com/ossez/convertlisttomap/ListToMapUnitTest.java
rename to core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/convertlisttomap/ListToMapUnitTest.java
diff --git a/java-collections-conversions-2/src/test/java/com/ossez/modelmapper/UsersListMappingUnitTest.java b/core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/modelmapper/UsersListMappingUnitTest.java
similarity index 100%
rename from java-collections-conversions-2/src/test/java/com/ossez/modelmapper/UsersListMappingUnitTest.java
rename to core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/modelmapper/UsersListMappingUnitTest.java
diff --git a/java-collections-conversions-2/src/test/java/com/ossez/setiteration/SetIteration.java b/core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/setiteration/SetIteration.java
similarity index 100%
rename from java-collections-conversions-2/src/test/java/com/ossez/setiteration/SetIteration.java
rename to core-java-modules/core-java-collections-conversions-2/src/test/java/com/ossez/setiteration/SetIteration.java
diff --git a/core-java-modules/core-java-collections-conversions/README.md b/core-java-modules/core-java-collections-conversions/README.md
index a952b5c1a4..a0102bc082 100644
--- a/core-java-modules/core-java-collections-conversions/README.md
+++ b/core-java-modules/core-java-collections-conversions/README.md
@@ -1,9 +1,10 @@
 ## Java 集合（Collections）相关文章和实例
 
-本模块中的内容包含有 Java 集合（Collections）转换相关的方法。
+本模块中的内容包含有 Java 集合（Collections）和数组（arrays）中进行转换。
 
 ### 相关文章
-- [Converting between an Array and a List in Java](https://www.baeldung.com/convert-array-to-list-and-list-to-array)
+
+- [Java 如何在 Array 和 List 之间进行转换](https://www.ossez.com/t/java-array-list/14416)
 - [Converting Between an Array and a Set in Java](https://www.baeldung.com/convert-array-to-set-and-set-to-array)
 - [Java 把 Map 的值（Value）转换为 Array, List 或 Set](https://www.ossez.com/t/java-map-value-array-list-set/14388)
 - [Converting a List to String in Java](https://www.baeldung.com/java-list-to-string)
diff --git a/core-java-modules/pom.xml b/core-java-modules/pom.xml
index fd197093eb..23eb5072b2 100644
--- a/core-java-modules/pom.xml
+++ b/core-java-modules/pom.xml
@@ -25,6 +25,7 @@
         <module>core-java-collections-2</module>
         <module>core-java-collections-3</module>
         <module>core-java-collections-conversions</module>
+        <module>core-java-collections-conversions-2</module>
         <module>core-java-collections-list</module>
         <module>core-java-collections-list-2</module>
         <module>core-java-collections-list-3</module>
diff --git a/java-collections-conversions-2/README.md b/java-collections-conversions-2/README.md
deleted file mode 100644
index bf5f7ced73..0000000000
--- a/java-collections-conversions-2/README.md
+++ /dev/null
@@ -1,12 +0,0 @@
-## Java Collections Cookbooks and Examples
-
-This module contains articles about conversions among Collection types and arrays in Java.
-
-### Relevant Articles: 
-
-- [Java Array 和 String 的转换](https://www.ossez.com/t/java-array-string/13685)
-- [Mapping Lists with ModelMapper](https://www.baeldung.com/java-modelmapper-lists)
-- [Converting List to Map With a Custom Supplier](https://www.baeldung.com/list-to-map-supplier)
-- [Java Arrays.asList 和 new ArrayList(Arrays.asList()) 的对比](https://www.ossez.com/t/java-arrays-aslist-new-arraylist-arrays-aslist/13680)
-- [Iterate Over a Set in Java](https://www.baeldung.com/java-iterate-set)
-- More articles: [[<-- prev]](../java-collections-conversions)
diff --git a/java-collections-conversions/README.md b/java-collections-conversions/README.md
deleted file mode 100644
index c640cf0a52..0000000000
--- a/java-collections-conversions/README.md
+++ /dev/null
@@ -1,16 +0,0 @@
-## Java 集合模块和实例（Core Java）
-
-本模块中的内容包括有如何在 Java 的集合和数组（arrays）中进行转换。
-
-### 相关文章：
-
-- [Java 如何在 Array 和 List 之间进行转换](https://www.ossez.com/t/java-array-list/14416)
-- [Converting between an Array and a Set in Java](https://www.baeldung.com/convert-array-to-set-and-set-to-array)
-- [Convert a Map to an Array, List or Set in Java](https://www.baeldung.com/convert-map-values-to-array-list-set)
-- [Converting a List to String in Java](https://www.baeldung.com/java-list-to-string)
-- [How to Convert List to Map in Java](https://www.baeldung.com/java-list-to-map)
-- [Converting a Collection to ArrayList in Java](https://www.baeldung.com/java-convert-collection-arraylist)
-- [Java 8 Collectors toMap](https://www.baeldung.com/java-collectors-tomap)
-- [Converting Iterable to Collection in Java](https://www.baeldung.com/java-iterable-to-collection)
-- [Converting Iterator to List](https://www.baeldung.com/java-convert-iterator-to-list)
-- More articles: [[next -->]](../java-collections-conversions-2)
\ No newline at end of file
diff --git a/java-collections-conversions/pom.xml b/java-collections-conversions/pom.xml
deleted file mode 100644
index bb8351d963..0000000000
--- a/java-collections-conversions/pom.xml
+++ /dev/null
@@ -1,52 +0,0 @@
-<?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>java-collections-conversions</artifactId>
-    <version>0.1.0-SNAPSHOT</version>
-    <name>java-collections-conversions</name>
-    <packaging>jar</packaging>
-
-    <parent>
-        <groupId>com.ossez</groupId>
-        <artifactId>parent-java</artifactId>
-        <version>0.0.2-SNAPSHOT</version>
-        <relativePath>../parent-java</relativePath>
-    </parent>
-
-
-    <dependencies>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-collections4</artifactId>
-            <version>${commons-collections4.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-lang3</artifactId>
-            <version>${commons-lang3.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.assertj</groupId>
-            <artifactId>assertj-core</artifactId>
-            <version>${assertj.version}</version>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <finalName>java-collections-conversions</finalName>
-        <resources>
-            <resource>
-                <directory>src/main/resources</directory>
-                <filtering>true</filtering>
-            </resource>
-        </resources>
-    </build>
-
-    <properties>
-        <commons-collections4.version>4.1</commons-collections4.version>
-    </properties>
-
-</project>
\ No newline at end of file
diff --git a/java-collections-conversions/src/main/java/com/ossez/convertToMap/Book.java b/java-collections-conversions/src/main/java/com/ossez/convertToMap/Book.java
deleted file mode 100644
index 2a4e969ae6..0000000000
--- a/java-collections-conversions/src/main/java/com/ossez/convertToMap/Book.java
+++ /dev/null
@@ -1,48 +0,0 @@
-package com.ossez.convertToMap;
-
-public class Book {
-    private String name;
-    private int releaseYear;
-    private String isbn;
-
-
-    @Override
-    public String toString() {
-        return "Book{" +
-                "name='" + name + '\'' +
-                ", releaseYear=" + releaseYear +
-                ", isbn='" + isbn + '\'' +
-                '}';
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    public int getReleaseYear() {
-        return releaseYear;
-    }
-
-    public void setReleaseYear(int releaseYear) {
-        this.releaseYear = releaseYear;
-    }
-
-    public String getIsbn() {
-        return isbn;
-    }
-
-    public void setIsbn(String isbn) {
-        this.isbn = isbn;
-    }
-
-    public Book(String name, int releaseYear, String isbn) {
-        this.name = name;
-        this.releaseYear = releaseYear;
-        this.isbn = isbn;
-    }
-}
-
diff --git a/java-collections-conversions/src/main/java/com/ossez/convertToMap/ConvertToMap.java b/java-collections-conversions/src/main/java/com/ossez/convertToMap/ConvertToMap.java
deleted file mode 100644
index 61393a0ac5..0000000000
--- a/java-collections-conversions/src/main/java/com/ossez/convertToMap/ConvertToMap.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package com.ossez.convertToMap;
-
-import java.util.*;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.Function;
-import java.util.stream.Collectors;
-
-public class ConvertToMap {
-    public Map<String, String> listToMap(List<Book> books) {
-        return books.stream().collect(Collectors.toMap(Book::getIsbn, Book::getName));
-    }
-
-    public Map<Integer, Book> listToMapWithDupKeyError(List<Book> books) {
-        return books.stream().collect(Collectors.toMap(Book::getReleaseYear, Function.identity()));
-    }
-
-    public Map<Integer, Book> listToMapWithDupKey(List<Book> books) {
-        return books.stream().collect(Collectors.toMap(Book::getReleaseYear, Function.identity(), (existing, replacement) -> existing));
-    }
-
-    public Map<Integer, Book> listToConcurrentMap(List<Book> books) {
-        return books.stream().collect(Collectors.toMap(Book::getReleaseYear, Function.identity(), (o1, o2) -> o1, ConcurrentHashMap::new));
-    }
-
-    public TreeMap<String, Book> listToSortedMap(List<Book> books) {
-        return books.stream()
-                .collect(Collectors.toMap(Book::getName, Function.identity(), (o1, o2) -> o1, TreeMap::new));
-    }
-}
-
diff --git a/java-collections-conversions/src/main/java/com/ossez/convertcollectiontoarraylist/Foo.java b/java-collections-conversions/src/main/java/com/ossez/convertcollectiontoarraylist/Foo.java
deleted file mode 100644
index 9a54f000bf..0000000000
--- a/java-collections-conversions/src/main/java/com/ossez/convertcollectiontoarraylist/Foo.java
+++ /dev/null
@@ -1,52 +0,0 @@
-package com.ossez.convertcollectiontoarraylist;
-
-/**
- * This POJO is the element type of our collection. It has a deepCopy() method.
- *
- * @author chris
- */
-public class Foo {
-
-    private int id;
-    private String name;
-    private Foo parent;
-
-    public Foo() {
-    }
-
-    public Foo(int id, String name, Foo parent) {
-        this.id = id;
-        this.name = name;
-        this.parent = parent;
-    }
-
-    public int getId() {
-        return id;
-    }
-
-    public void setId(int id) {
-        this.id = id;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    public Foo getParent() {
-        return parent;
-    }
-
-    public void setParent(Foo parent) {
-        this.parent = parent;
-    }
-
-    public Foo deepCopy() {
-        return new Foo(
-          this.id, this.name, this.parent != null ? this.parent.deepCopy() : null);
-    }
-
-}
diff --git a/java-collections-conversions/src/main/java/com/ossez/convertlisttomap/Animal.java b/java-collections-conversions/src/main/java/com/ossez/convertlisttomap/Animal.java
deleted file mode 100644
index c8d9fdfcaf..0000000000
--- a/java-collections-conversions/src/main/java/com/ossez/convertlisttomap/Animal.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package com.ossez.convertlisttomap;
-
-public class Animal {
-    private int id;
-    private String name;
-
-    public Animal(int id, String name) {
-        this.id = id;
-        this.setName(name);
-    }
-
-    public int getId() {
-        return id;
-    }
-
-    public void setId(int id) {
-        this.id = id;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-}
diff --git a/java-collections-conversions/src/main/java/com/ossez/convertlisttomap/ConvertListToMapService.java b/java-collections-conversions/src/main/java/com/ossez/convertlisttomap/ConvertListToMapService.java
deleted file mode 100644
index d162183f56..0000000000
--- a/java-collections-conversions/src/main/java/com/ossez/convertlisttomap/ConvertListToMapService.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package com.ossez.convertlisttomap;
-
-import com.google.common.collect.Maps;
-import org.apache.commons.collections4.MapUtils;
-
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.function.Function;
-import java.util.stream.Collectors;
-
-public class ConvertListToMapService {
-
-    public Map<Integer, Animal> convertListBeforeJava8(List<Animal> list) {
-
-        Map<Integer, Animal> map = new HashMap<>();
-
-        for (Animal animal : list) {
-            map.put(animal.getId(), animal);
-        }
-        return map;
-    }
-
-    public Map<Integer, Animal> convertListAfterJava8(List<Animal> list) {
-        Map<Integer, Animal> map = list.stream().collect(Collectors.toMap(Animal::getId, Function.identity()));
-        return map;
-    }
-
-    public Map<Integer, Animal> convertListWithGuava(List<Animal> list) {
-
-        Map<Integer, Animal> map = Maps.uniqueIndex(list, Animal::getId);
-        return map;
-    }
-
-    public Map<Integer, Animal> convertListWithApacheCommons(List<Animal> list) {
-
-        Map<Integer, Animal> map = new HashMap<>();
-
-        MapUtils.populateMap(map, list, Animal::getId);
-
-        return map;
-    }
-}
diff --git a/java-collections-conversions/src/main/resources/logback.xml b/java-collections-conversions/src/main/resources/logback.xml
deleted file mode 100644
index 7d900d8ea8..0000000000
--- a/java-collections-conversions/src/main/resources/logback.xml
+++ /dev/null
@@ -1,13 +0,0 @@
-<?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>
\ No newline at end of file
diff --git a/java-collections-conversions/src/test/java/com/ossez/arrayconversion/ArrayToListConversionUnitTest.java b/java-collections-conversions/src/test/java/com/ossez/arrayconversion/ArrayToListConversionUnitTest.java
deleted file mode 100644
index 153d515d1b..0000000000
--- a/java-collections-conversions/src/test/java/com/ossez/arrayconversion/ArrayToListConversionUnitTest.java
+++ /dev/null
@@ -1,51 +0,0 @@
-package com.ossez.arrayconversion;
-
-import org.assertj.core.api.ListAssert;
-import org.hamcrest.CoreMatchers;
-import org.junit.Test;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-/**
- * <p>
- * ArrayToListConversionUnitTest
- * <ul>
- * <li>@see <a href= "https://www.ossez.com/t/java-arrays-aslist-new-arraylist-arrays-aslist/13680">Arrays.asList vs new ArrayList(Arrays.asList())</a>
- * </li>
- * </ul>
- * </p>
- *
- * @author YuCheng
- */
-
- /*Line 1
- Line 2
- Line 3*/
-
-public class ArrayToListConversionUnitTest {
-
-    @Test(expected = UnsupportedOperationException.class)
-    public void givenAnArray_whenConvertingToList_returnUnmodifiableListUnitTest() {
-        String[] stringArray = new String[]{"A", "B", "C", "D"};
-        List<String> stringList = Arrays.asList(stringArray);
-        stringList.set(0, "E");
-        assertThat(stringList).containsExactly("E", "B", "C", "D");
-        assertThat(stringArray).containsExactly("E", "B", "C", "D");
-        stringList.add("F");
-    }
-
-    @Test
-    public void givenAnArray_whenConvertingToList_returnModifiableListUnitTest() {
-        String[] stringArray = new String[]{"A", "B", "C", "D"};
-        List<String> stringList = new ArrayList<>(Arrays.asList(stringArray));
-        stringList.set(0, "E");
-        assertThat(stringList).containsExactly("E", "B", "C", "D");
-        assertThat(stringArray).containsExactly("A", "B", "C", "D");
-        stringList.add("F");
-        assertThat(stringList).containsExactly("E", "B", "C", "D", "F");
-    }
-}
\ No newline at end of file
diff --git a/java-collections-conversions/src/test/java/com/ossez/convertToMap/ConvertToMapUnitTest.java b/java-collections-conversions/src/test/java/com/ossez/convertToMap/ConvertToMapUnitTest.java
deleted file mode 100644
index 745a801698..0000000000
--- a/java-collections-conversions/src/test/java/com/ossez/convertToMap/ConvertToMapUnitTest.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package com.ossez.convertToMap;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
-
-import static org.junit.Assert.*;
-
-import org.junit.Before;
-import org.junit.Test;
-
-
-public class ConvertToMapUnitTest {
-
-    private List<Book> bookList;
-    private ConvertToMap convertToMap = new ConvertToMap();
-
-    @Before
-    public void init() {
-        bookList = new ArrayList<>();
-        bookList.add(new Book("The Fellowship of the Ring", 1954, "0395489318"));
-        bookList.add(new Book("The Two Towers", 1954, "0345339711"));
-        bookList.add(new Book("The Return of the King", 1955, "0618129111"));
-    }
-
-    @Test
-    public void whenConvertFromListToMap() {
-        assertTrue(convertToMap.listToMap(bookList).size() == 3);
-    }
-
-    @Test(expected = IllegalStateException.class)
-    public void whenMapHasDuplicateKey_without_merge_function_then_runtime_exception() {
-        convertToMap.listToMapWithDupKeyError(bookList);
-    }
-
-    @Test
-    public void whenMapHasDuplicateKeyThenMergeFunctionHandlesCollision() {
-        Map<Integer, Book> booksByYear = convertToMap.listToMapWithDupKey(bookList);
-        assertEquals(2, booksByYear.size());
-        assertEquals("0395489318", booksByYear.get(1954).getIsbn());
-    }
-
-    @Test
-    public void whenCreateConcurrentHashMap() {
-        assertTrue(convertToMap.listToConcurrentMap(bookList) instanceof ConcurrentHashMap);
-    }
-
-    @Test
-    public void whenMapisSorted() {
-        assertTrue(convertToMap.listToSortedMap(bookList).firstKey().equals("The Fellowship of the Ring"));
-    }
-}
diff --git a/java-collections-conversions/src/test/java/com/ossez/convertcollectiontoarraylist/CollectionToArrayListUnitTest.java b/java-collections-conversions/src/test/java/com/ossez/convertcollectiontoarraylist/CollectionToArrayListUnitTest.java
deleted file mode 100644
index be470671a7..0000000000
--- a/java-collections-conversions/src/test/java/com/ossez/convertcollectiontoarraylist/CollectionToArrayListUnitTest.java
+++ /dev/null
@@ -1,145 +0,0 @@
-package com.ossez.convertcollectiontoarraylist;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Comparator;
-import java.util.HashSet;
-import java.util.Iterator;
-import static java.util.stream.Collectors.toCollection;
-import org.junit.BeforeClass;
-import org.junit.Test;
-import static org.junit.Assert.*;
-
-/**
- *
- * @author chris
- */
-public class CollectionToArrayListUnitTest {
-    private static Collection<Foo> srcCollection = new HashSet<>();
-
-    public CollectionToArrayListUnitTest() {
-    }
-    
-    @BeforeClass
-    public static void setUpClass() {
-        int i = 0;
-        Foo john = new Foo(i++, "John", null);
-        Foo mary = new Foo(i++, "Mary", null);
-        Foo sam = new Foo(i++, "Sam", john);
-        Foo alice = new Foo(i++, "Alice", john);
-        Foo buffy = new Foo(i++, "Buffy", sam);
-        srcCollection.add(john);
-        srcCollection.add(mary);
-        srcCollection.add(sam);
-        srcCollection.add(alice);
-        srcCollection.add(buffy);
-    }
-    
-    /**
-     * Section 3. Using the ArrayList Constructor
-     */
-    @Test
-    public void whenUsingConstructor_thenVerifyShallowCopy() {
-        ArrayList<Foo> newList = new ArrayList<>(srcCollection);
-        verifyShallowCopy(srcCollection, newList);
-    }
-    
-    /**
-     * Section 4. Using the Streams API
-     */
-    @Test
-    public void whenUsingStream_thenVerifyShallowCopy() {
-        ArrayList<Foo> newList = srcCollection.stream().collect(toCollection(ArrayList::new));
-
-        verifyShallowCopy(srcCollection, newList);
-    }
-
-    /**
-     * Section 5. Deep Copy
-     */
-    @Test
-    public void whenUsingDeepCopy_thenVerifyDeepCopy() {
-        ArrayList<Foo> newList = srcCollection.stream()
-          .map(Foo::deepCopy)
-          .collect(toCollection(ArrayList::new));
-
-        verifyDeepCopy(srcCollection, newList);
-    }
-    
-    /**
-     * Section 6. Controlling the List Order
-     */
-    @Test
-    public void whenUsingSortedStream_thenVerifySortOrder() {
-        ArrayList<Foo> newList = srcCollection.stream()
-          .sorted(Comparator.comparing(Foo::getName))
-          .collect(toCollection(ArrayList::new));
-
-        assertTrue("ArrayList is not sorted by name", isSorted(newList));
-    }
-    
-    /**
-     * Verify that the contents of the two collections are the same
-     * @param a
-     * @param b 
-     */
-    private void verifyShallowCopy(Collection<Foo> a, Collection<Foo> b) {
-        assertEquals("Collections have different lengths", a.size(), b.size());
-        Iterator<Foo> iterA = a.iterator();
-        Iterator<Foo> iterB = b.iterator();
-        while (iterA.hasNext()) {
-            // test instance identity
-            assertSame("Foo instances differ!", iterA.next(), iterB.next());
-        }
-    }
-    
-    /**
-     * Verify that the contents of the two collections are the same
-     * @param a
-     * @param b 
-     */
-    private void verifyDeepCopy(Collection<Foo> a, Collection<Foo> b) {
-        assertEquals("Collections have different lengths", a.size(), b.size());
-        Iterator<Foo> iterA = a.iterator();
-        Iterator<Foo> iterB = b.iterator();
-        while (iterA.hasNext()) {
-            Foo nextA = iterA.next();
-            Foo nextB = iterB.next();
-            // should not be same instance
-            assertNotSame("Foo instances are the same!", nextA, nextB);
-            // but should have same content
-            assertFalse("Foo instances have different content!", fooDiff(nextA, nextB));
-        }
-    }
-
-    /**
-     * Return true if the contents of a and b differ.  Test parent recursively
-     * @param a
-     * @param b
-     * @return False if the two items are the same
-     */
-    private boolean fooDiff(Foo a, Foo b) {
-        if (a != null && b != null) {
-            return a.getId() != b.getId() 
-              || !a.getName().equals(b.getName()) 
-              || fooDiff(a.getParent(), b.getParent());
-        }
-        return !(a == null && b == null);
-    }
-    
-    /**
-     * @param c collection of Foo
-     * @return true if the collection is sorted by name
-     */
-    private static boolean isSorted(Collection<Foo> c) {
-        String prevName = null;
-        for (Foo foo : c) {
-            if (prevName == null || foo.getName().compareTo(prevName) > 0) {
-                prevName = foo.getName();
-            } else {
-                return false;
-            }
-        }
-        return true;
-    }
-}
diff --git a/java-collections-conversions/src/test/java/com/ossez/convertiteratortolist/ConvertIteratorToListServiceUnitTest.java b/java-collections-conversions/src/test/java/com/ossez/convertiteratortolist/ConvertIteratorToListServiceUnitTest.java
deleted file mode 100644
index 97ba2e4326..0000000000
--- a/java-collections-conversions/src/test/java/com/ossez/convertiteratortolist/ConvertIteratorToListServiceUnitTest.java
+++ /dev/null
@@ -1,100 +0,0 @@
-package com.ossez.convertiteratortolist;
-
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.collection.IsCollectionWithSize.hasSize;
-import static org.hamcrest.collection.IsIterableContainingInAnyOrder.containsInAnyOrder;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.List;
-import java.util.stream.Collectors;
-import java.util.stream.StreamSupport;
-
-import org.apache.commons.collections4.IteratorUtils;
-import org.junit.Before;
-import org.junit.Test;
-
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Lists;
-
-public class ConvertIteratorToListServiceUnitTest {
-
-    Iterator<Integer> iterator;
-
-    @Before
-    public void setUp() {
-        iterator = Arrays.asList(1, 2, 3)
-            .iterator();
-    }
-
-    @Test
-    public void givenAnIterator_whenConvertIteratorToListUsingWhileLoop_thenReturnAList() {
-
-        List<Integer> actualList = new ArrayList<>();
-
-        // Convert Iterator to List using while loop dsf
-        while (iterator.hasNext()) {
-            actualList.add(iterator.next());
-        }
-
-        assertThat(actualList, hasSize(3));
-        assertThat(actualList, containsInAnyOrder(1, 2, 3));
-    }
-
-    @Test
-    public void givenAnIterator_whenConvertIteratorToListAfterJava8_thenReturnAList() {
-        List<Integer> actualList = new ArrayList<>();
-
-        // Convert Iterator to List using Java 8
-        iterator.forEachRemaining(actualList::add);
-
-        assertThat(actualList, hasSize(3));
-        assertThat(actualList, containsInAnyOrder(1, 2, 3));
-    }
-
-    @Test
-    public void givenAnIterator_whenConvertIteratorToListJava8Stream_thenReturnAList() {
-
-        // Convert iterator to iterable
-        Iterable<Integer> iterable = () -> iterator;
-
-        // Extract List from stream
-        List<Integer> actualList = StreamSupport
-            .stream(iterable.spliterator(), false)
-            .collect(Collectors.toList());
-
-        assertThat(actualList, hasSize(3));
-        assertThat(actualList, containsInAnyOrder(1, 2, 3));
-    }
-
-    @Test
-    public void givenAnIterator_whenConvertIteratorToImmutableListWithGuava_thenReturnAList() {
-
-        // Convert Iterator to an Immutable list using Guava library in Java
-        List<Integer> actualList = ImmutableList.copyOf(iterator);
-
-        assertThat(actualList, hasSize(3));
-        assertThat(actualList, containsInAnyOrder(1, 2, 3));
-    }
-
-    @Test
-    public void givenAnIterator_whenConvertIteratorToMutableListWithGuava_thenReturnAList() {
-
-        // Convert Iterator to a mutable list using Guava library in Java
-        List<Integer> actualList = Lists.newArrayList(iterator);
-
-        assertThat(actualList, hasSize(3));
-        assertThat(actualList, containsInAnyOrder(1, 2, 3));
-    }
-
-    @Test
-    public void givenAnIterator_whenConvertIteratorToMutableListWithApacheCommons_thenReturnAList() {
-
-        // Convert Iterator to a mutable list using Apache Commons library in Java
-        List<Integer> actualList = IteratorUtils.toList(iterator);
-
-        assertThat(actualList, hasSize(3));
-        assertThat(actualList, containsInAnyOrder(1, 2, 3));
-    }
-}
diff --git a/java-collections-conversions/src/test/java/com/ossez/convertlisttomap/ConvertListToMapServiceUnitTest.java b/java-collections-conversions/src/test/java/com/ossez/convertlisttomap/ConvertListToMapServiceUnitTest.java
deleted file mode 100644
index e538cfc9b9..0000000000
--- a/java-collections-conversions/src/test/java/com/ossez/convertlisttomap/ConvertListToMapServiceUnitTest.java
+++ /dev/null
@@ -1,68 +0,0 @@
-package com.ossez.convertlisttomap;
-
-import org.junit.Before;
-import org.junit.Test;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.containsInAnyOrder;
-
-public class ConvertListToMapServiceUnitTest {
-    List<Animal> list;
-
-    private ConvertListToMapService convertListService;
-
-    @Before
-    public void init() {
-        this.convertListService = new ConvertListToMapService();
-        this.list = new ArrayList<>();
-
-        Animal cat = new Animal(1, "Cat");
-        list.add(cat);
-        Animal dog = new Animal(2, "Dog");
-        list.add(dog);
-        Animal pig = new Animal(3, "Pig");
-        list.add(pig);
-        Animal cow = new Animal(4, "Cow");
-        list.add(cow);
-        Animal goat = new Animal(5, "Goat");
-        list.add(goat);
-
-    }
-
-    @Test
-    public void givenAList_whenConvertBeforeJava8_thenReturnMapWithTheSameElements() {
-
-        Map<Integer, Animal> map = convertListService.convertListBeforeJava8(list);
-
-        assertThat(map.values(), containsInAnyOrder(list.toArray()));
-    }
-
-    @Test
-    public void givenAList_whenConvertAfterJava8_thenReturnMapWithTheSameElements() {
-
-        Map<Integer, Animal> map = convertListService.convertListAfterJava8(list);
-
-        assertThat(map.values(), containsInAnyOrder(list.toArray()));
-    }
-
-    @Test
-    public void givenAList_whenConvertWithGuava_thenReturnMapWithTheSameElements() {
-
-        Map<Integer, Animal> map = convertListService.convertListWithGuava(list);
-
-        assertThat(map.values(), containsInAnyOrder(list.toArray()));
-    }
-
-    @Test
-    public void givenAList_whenConvertWithApacheCommons_thenReturnMapWithTheSameElements() {
-
-        Map<Integer, Animal> map = convertListService.convertListWithApacheCommons(list);
-
-        assertThat(map.values(), containsInAnyOrder(list.toArray()));
-    }
-
-}
diff --git a/java-collections-conversions/src/test/java/com/ossez/convertlisttomap/ConvertListWithDuplicatedIdToMapServiceUnitTest.java b/java-collections-conversions/src/test/java/com/ossez/convertlisttomap/ConvertListWithDuplicatedIdToMapServiceUnitTest.java
deleted file mode 100644
index 51336cb0aa..0000000000
--- a/java-collections-conversions/src/test/java/com/ossez/convertlisttomap/ConvertListWithDuplicatedIdToMapServiceUnitTest.java
+++ /dev/null
@@ -1,68 +0,0 @@
-package com.ossez.convertlisttomap;
-
-import org.junit.Before;
-import org.junit.Test;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Map;
-
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.hasItem;
-import static org.hamcrest.Matchers.hasSize;
-
-public class ConvertListWithDuplicatedIdToMapServiceUnitTest {
-    List<Animal> duplicatedIdList;
-
-    private ConvertListToMapService convertListService = new ConvertListToMapService();
-
-    @Before
-    public void init() {
-
-        this.duplicatedIdList = new ArrayList<>();
-
-        Animal cat = new Animal(1, "Cat");
-        duplicatedIdList.add(cat);
-        Animal dog = new Animal(2, "Dog");
-        duplicatedIdList.add(dog);
-        Animal pig = new Animal(3, "Pig");
-        duplicatedIdList.add(pig);
-        Animal cow = new Animal(4, "Cow");
-        duplicatedIdList.add(cow);
-        Animal goat = new Animal(4, "Goat");
-        duplicatedIdList.add(goat);
-
-    }
-
-    @Test
-    public void givenADupIdList_whenConvertBeforeJava8_thenReturnMapWithRewrittenElement() {
-
-        Map<Integer, Animal> map = convertListService.convertListBeforeJava8(duplicatedIdList);
-
-        assertThat(map.values(), hasSize(4));
-        assertThat(map.values(), hasItem(duplicatedIdList.get(4)));
-    }
-
-    @Test
-    public void givenADupIdList_whenConvertWithApacheCommons_thenReturnMapWithRewrittenElement() {
-
-        Map<Integer, Animal> map = convertListService.convertListWithApacheCommons(duplicatedIdList);
-
-        assertThat(map.values(), hasSize(4));
-        assertThat(map.values(), hasItem(duplicatedIdList.get(4)));
-    }
-
-    @Test(expected = IllegalStateException.class)
-    public void givenADupIdList_whenConvertAfterJava8_thenException() {
-
-        convertListService.convertListAfterJava8(duplicatedIdList);
-    }
-
-    @Test(expected = IllegalArgumentException.class)
-    public void givenADupIdList_whenConvertWithGuava_thenException() {
-
-        convertListService.convertListWithGuava(duplicatedIdList);
-
-    }
-
-}
diff --git a/java-collections-conversions/src/test/java/com/ossez/java/collections/IterableToCollectionUnitTest.java b/java-collections-conversions/src/test/java/com/ossez/java/collections/IterableToCollectionUnitTest.java
deleted file mode 100644
index 22293a7c77..0000000000
--- a/java-collections-conversions/src/test/java/com/ossez/java/collections/IterableToCollectionUnitTest.java
+++ /dev/null
@@ -1,122 +0,0 @@
-package com.ossez.java.collections;
-
-import static org.hamcrest.Matchers.contains;
-import static org.junit.Assert.assertThat;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Spliterator;
-import java.util.Spliterators;
-import java.util.stream.Collectors;
-import java.util.stream.StreamSupport;
-
-import org.apache.commons.collections4.IterableUtils;
-import org.apache.commons.collections4.IteratorUtils;
-import org.junit.Test;
-
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Lists;
-
-public class IterableToCollectionUnitTest {
-
-    Iterable<String> iterable = Arrays.asList("john", "tom", "jane");
-    Iterator<String> iterator = iterable.iterator();
-
-    @Test
-    public void whenConvertIterableToListUsingJava_thenSuccess() {
-        List<String> result = new ArrayList<String>();
-        for (String str : iterable) {
-            result.add(str);
-        }
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIterableToListUsingJava8_thenSuccess() {
-        List<String> result = new ArrayList<String>();
-        iterable.forEach(result::add);
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIterableToListUsingJava8WithSpliterator_thenSuccess() {
-        List<String> result = StreamSupport.stream(iterable.spliterator(), false)
-            .collect(Collectors.toList());
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIterableToListUsingGuava_thenSuccess() {
-        List<String> result = Lists.newArrayList(iterable);
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIterableToImmutableListUsingGuava_thenSuccess() {
-        List<String> result = ImmutableList.copyOf(iterable);
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIterableToListUsingApacheCommons_thenSuccess() {
-        List<String> result = IterableUtils.toList(iterable);
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    // ======================== Iterator
-
-    @Test
-    public void whenConvertIteratorToListUsingJava_thenSuccess() {
-        List<String> result = new ArrayList<String>();
-        while (iterator.hasNext()) {
-            result.add(iterator.next());
-        }
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIteratorToListUsingJava8_thenSuccess() {
-        List<String> result = new ArrayList<String>();
-        iterator.forEachRemaining(result::add);
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIteratorToListUsingJava8WithSpliterator_thenSuccess() {
-        List<String> result = StreamSupport.stream(Spliterators.spliteratorUnknownSize(iterator, Spliterator.ORDERED), false)
-            .collect(Collectors.toList());
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIteratorToListUsingGuava_thenSuccess() {
-        List<String> result = Lists.newArrayList(iterator);
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIteratorToImmutableListUsingGuava_thenSuccess() {
-        List<String> result = ImmutableList.copyOf(iterator);
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-
-    @Test
-    public void whenConvertIteratorToListUsingApacheCommons_thenSuccess() {
-        List<String> result = IteratorUtils.toList(iterator);
-
-        assertThat(result, contains("john", "tom", "jane"));
-    }
-}
diff --git a/java-collections-conversions/src/test/java/com/ossez/java/collections/JavaCollectionConversionUnitTest.java b/java-collections-conversions/src/test/java/com/ossez/java/collections/JavaCollectionConversionUnitTest.java
deleted file mode 100644
index fdcbe1bf9f..0000000000
--- a/java-collections-conversions/src/test/java/com/ossez/java/collections/JavaCollectionConversionUnitTest.java
+++ /dev/null
@@ -1,145 +0,0 @@
-package com.ossez.java.collections;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-import org.apache.commons.collections4.CollectionUtils;
-import org.apache.commons.lang3.ArrayUtils;
-import org.junit.Test;
-
-import com.google.common.collect.Lists;
-import com.google.common.collect.Sets;
-import com.google.common.primitives.Ints;
-
-@SuppressWarnings("unused")
-public class JavaCollectionConversionUnitTest {
-
-    // List -> array; array -> List
-
-    @Test
-    public final void givenUsingCoreJava_whenArrayConvertedToList_thenCorrect() {
-        final Integer[] sourceArray = { 0, 1, 2, 3, 4, 5 };
-        final List<Integer> targetList = Arrays.asList(sourceArray);
-    }
-
-    @Test
-    public final void givenUsingCoreJava_whenListConvertedToArray_thenCorrect() {
-        final List<Integer> sourceList = Arrays.asList(0, 1, 2, 3, 4, 5);
-        final Integer[] targetArray = sourceList.toArray(new Integer[0]);
-    }
-
-    @Test
-    public final void givenUsingGuava_whenArrayConvertedToList_thenCorrect() {
-        final Integer[] sourceArray = { 0, 1, 2, 3, 4, 5 };
-        final List<Integer> targetList = Lists.newArrayList(sourceArray);
-    }
-
-    @Test
-    public final void givenUsingGuava_whenListConvertedToArray_thenCorrect() {
-        final List<Integer> sourceList = Lists.newArrayList(0, 1, 2, 3, 4, 5);
-        final int[] targetArray = Ints.toArray(sourceList);
-    }
-
-    @Test
-    public final void givenUsingCommonsCollections_whenArrayConvertedToList_thenCorrect() {
-        final Integer[] sourceArray = { 0, 1, 2, 3, 4, 5 };
-        final List<Integer> targetList = new ArrayList<>(6);
-        CollectionUtils.addAll(targetList, sourceArray);
-    }
-
-    // Set -> array; array -> Set
-
-    @Test
-    public final void givenUsingCoreJavaV1_whenArrayConvertedToSet_thenCorrect() {
-        final Integer[] sourceArray = { 0, 1, 2, 3, 4, 5 };
-        final Set<Integer> targetSet = new HashSet<Integer>(Arrays.asList(sourceArray));
-    }
-
-    @Test
-    public final void givenUsingCoreJavaV2_whenArrayConvertedToSet_thenCorrect() {
-        final Integer[] sourceArray = { 0, 1, 2, 3, 4, 5 };
-        final Set<Integer> targetSet = new HashSet<Integer>();
-        Collections.addAll(targetSet, sourceArray);
-    }
-
-    @Test
-    public final void givenUsingCoreJava_whenSetConvertedToArray_thenCorrect() {
-        final Set<Integer> sourceSet = Sets.newHashSet(0, 1, 2, 3, 4, 5);
-        final Integer[] targetArray = sourceSet.toArray(new Integer[0]);
-    }
-
-    @Test
-    public final void givenUsingGuava_whenArrayConvertedToSet_thenCorrect() {
-        final Integer[] sourceArray = { 0, 1, 2, 3, 4, 5 };
-        final Set<Integer> targetSet = Sets.newHashSet(sourceArray);
-    }
-
-    @Test
-    public final void givenUsingGuava_whenSetConvertedToArray_thenCorrect() {
-        final Set<Integer> sourceSet = Sets.newHashSet(0, 1, 2, 3, 4, 5);
-        final int[] targetArray = Ints.toArray(sourceSet);
-    }
-
-    @Test
-    public final void givenUsingCommonsCollections_whenArrayConvertedToSet_thenCorrect() {
-        final Integer[] sourceArray = { 0, 1, 2, 3, 4, 5 };
-        final Set<Integer> targetSet = new HashSet<>(6);
-        CollectionUtils.addAll(targetSet, sourceArray);
-    }
-
-    @Test
-    public final void givenUsingCommonsCollections_whenSetConvertedToArrayOfPrimitives_thenCorrect() {
-        final Set<Integer> sourceSet = Sets.newHashSet(0, 1, 2, 3, 4, 5);
-        final Integer[] targetArray = sourceSet.toArray(new Integer[0]);
-        final int[] primitiveTargetArray = ArrayUtils.toPrimitive(targetArray);
-    }
-
-    // Map (values) -> Array, List, Set
-
-    @Test
-    public final void givenUsingCoreJava_whenMapValuesConvertedToArray_thenCorrect() {
-        final Map<Integer, String> sourceMap = createMap();
-
-        final Collection<String> values = sourceMap.values();
-        final String[] targetArray = values.toArray(new String[0]);
-    }
-
-    @Test
-    public final void givenUsingCoreJava_whenMapValuesConvertedToList_thenCorrect() {
-        final Map<Integer, String> sourceMap = createMap();
-
-        final List<String> targetList = new ArrayList<>(sourceMap.values());
-    }
-
-    @Test
-    public final void givenUsingGuava_whenMapValuesConvertedToList_thenCorrect() {
-        final Map<Integer, String> sourceMap = createMap();
-
-        final List<String> targetList = Lists.newArrayList(sourceMap.values());
-    }
-
-    @Test
-    public final void givenUsingCoreJava_whenMapValuesConvertedToSet_thenCorrect() {
-        final Map<Integer, String> sourceMap = createMap();
-
-        final Set<String> targetSet = new HashSet<>(sourceMap.values());
-    }
-
-    // UTIL
-
-    private final Map<Integer, String> createMap() {
-        final Map<Integer, String> sourceMap = new HashMap<>(3);
-        sourceMap.put(0, "zero");
-        sourceMap.put(1, "one");
-        sourceMap.put(2, "two");
-        return sourceMap;
-    }
-
-}
diff --git a/java-collections-conversions/src/test/java/com/ossez/java/lists/ListToStringUnitTest.java b/java-collections-conversions/src/test/java/com/ossez/java/lists/ListToStringUnitTest.java
deleted file mode 100644
index b05002b9f4..0000000000
--- a/java-collections-conversions/src/test/java/com/ossez/java/lists/ListToStringUnitTest.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package com.ossez.java.lists;
-
-import java.util.Arrays;
-import java.util.List;
-import java.util.stream.Collectors;
-
-import org.apache.commons.lang3.StringUtils;
-import org.junit.Test;
-
-public class ListToStringUnitTest {
-
-    @Test
-    public void whenListToString_thenPrintDefault() {
-        List<Integer> intLIst = Arrays.asList(1, 2, 3);
-        System.out.println(intLIst);
-    }
-
-    @Test
-    public void whenCollectorsJoining_thenPrintCustom() {
-        List<Integer> intList = Arrays.asList(1, 2, 3);
-        System.out.println(intList.stream()
-            .map(n -> String.valueOf(n))
-            .collect(Collectors.joining("-", "{", "}")));
-    }
-    
-    @Test
-    public void whenStringUtilsJoin_thenPrintCustom() {
-        List<Integer> intList = Arrays.asList(1, 2, 3);
-       System.out.println(StringUtils.join(intList, "|"));
-    }
-}
diff --git a/pom.xml b/pom.xml
index db34525e49..da5d2ba36f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -43,7 +43,6 @@
         <!--        <module>jackson-modules</module>-->
         <!--        <module>jackson-simple</module>-->
         <!--        <module>parent-java</module>-->
-        <module>java-collections-conversions</module>
         <module>persistence-modules</module>
         <module>testing-modules</module>
         <module>toolkits</module>