From e5d5c2dcbe62f8a4a18431d8fc69ca2f8c98e985 Mon Sep 17 00:00:00 2001
From: YuCheng Hu <huyuchengus@gmail.com>
Date: Fri, 21 Apr 2023 17:09:52 -0400
Subject: [PATCH] =?UTF-8?q?=E6=8A=8A=E6=96=87=E7=AB=A0=EF=BC=9Ahttps://www?=
 =?UTF-8?q?.ossez.com/t/java-map-value-array-list-set/14388=20=E8=BF=9B?=
 =?UTF-8?q?=E8=A1=8C=E6=9B=B4=E6=96=B0?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .idea/.gitignore                              |  10 --
 .idea/compiler.xml                            |  10 +-
 .idea/encodings.xml                           |   4 -
 .idea/jarRepositories.xml                     |  10 --
 .idea/php.xml                                 |  12 --
 .idea/thriftCompiler.xml                      |   6 -
 .../java/com/baeldung/convertToMap/Book.java  |  48 ------
 .../baeldung/convertToMap/ConvertToMap.java   |  30 ----
 .../convertcollectiontoarraylist/Foo.java     |  52 -------
 .../com/baeldung/convertlisttomap/Animal.java |  27 ----
 .../ConvertListToMapService.java              |  43 ------
 .../convertToMap/ConvertToMapUnitTest.java    |  53 -------
 .../CollectionToArrayListUnitTest.java        | 145 ------------------
 .../ConvertIteratorToListServiceUnitTest.java | 100 ------------
 .../ConvertListToMapServiceUnitTest.java      |  68 --------
 ...tWithDuplicatedIdToMapServiceUnitTest.java |  68 --------
 .../IterableToCollectionUnitTest.java         | 122 ---------------
 .../JavaCollectionConversionUnitTest.java     | 145 ------------------
 .../java/lists/ListToStringUnitTest.java      |  31 ----
 19 files changed, 2 insertions(+), 982 deletions(-)
 delete mode 100644 .idea/.gitignore
 delete mode 100644 .idea/php.xml
 delete mode 100644 .idea/thriftCompiler.xml
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertToMap/Book.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertToMap/ConvertToMap.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertcollectiontoarraylist/Foo.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/Animal.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/ConvertListToMapService.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertToMap/ConvertToMapUnitTest.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertcollectiontoarraylist/CollectionToArrayListUnitTest.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertiteratortolist/ConvertIteratorToListServiceUnitTest.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertlisttomap/ConvertListToMapServiceUnitTest.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertlisttomap/ConvertListWithDuplicatedIdToMapServiceUnitTest.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/collections/IterableToCollectionUnitTest.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/collections/JavaCollectionConversionUnitTest.java
 delete mode 100644 core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/lists/ListToStringUnitTest.java

diff --git a/.idea/.gitignore b/.idea/.gitignore
deleted file mode 100644
index 0a8642fac0..0000000000
--- a/.idea/.gitignore
+++ /dev/null
@@ -1,10 +0,0 @@
-# Default ignored files
-/shelf/
-/workspace.xml
-# Editor-based HTTP Client requests
-/httpRequests/
-# Datasource local storage ignored files
-/dataSources/
-/dataSources.local.xml
-# Zeppelin ignored files
-/ZeppelinRemoteNotebooks/
diff --git a/.idea/compiler.xml b/.idea/compiler.xml
index 0a977aecaa..7e75ee986b 100644
--- a/.idea/compiler.xml
+++ b/.idea/compiler.xml
@@ -2,7 +2,6 @@
 <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" />
@@ -22,10 +21,10 @@
         <module name="core-java" />
         <module name="core-java-11" />
         <module name="core-java-collections-conversions" />
-        <module name="core-java-collections-list-2" />
         <module name="core-java-collections" />
-        <module name="core-java-datetime-conversion" />
+        <module name="core-java-collections-list-2" />
         <module name="core-java-collections-list-3" />
+        <module name="core-java-datetime-conversion" />
         <module name="core-java-8" />
         <module name="junit-5-basics" />
         <module name="core-java-collections-3" />
@@ -33,11 +32,6 @@
         <module name="activejdbc" />
       </profile>
     </annotationProcessing>
-    <bytecodeTargetLevel>
-      <module name="core-java-11-2" target="11" />
-      <module name="hibernate-annotations" target="1.5" />
-      <module name="hibernate5" target="11" />
-    </bytecodeTargetLevel>
   </component>
   <component name="JavacSettings">
     <option name="ADDITIONAL_OPTIONS_OVERRIDE">
diff --git a/.idea/encodings.xml b/.idea/encodings.xml
index dc58147bcb..ae8a982717 100644
--- a/.idea/encodings.xml
+++ b/.idea/encodings.xml
@@ -1,8 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="Encoding">
-    <file url="file://$PROJECT_DIR$/core-java-modules/core-java-11-2/src/main/java" charset="UTF-8" />
-    <file url="file://$PROJECT_DIR$/core-java-modules/core-java-11-2/src/main/resources" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/core-java-modules/core-java-11/src/main/java" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/core-java-modules/core-java-11/src/main/resources" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/core-java-modules/core-java-8-2/src/main/java" charset="UTF-8" />
@@ -41,8 +39,6 @@
     <file url="file://$PROJECT_DIR$/core-java-modules/src/main/resources" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/persistence-modules/activejdbc/src/main/java" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/persistence-modules/activejdbc/src/main/resources" charset="UTF-8" />
-    <file url="file://$PROJECT_DIR$/persistence-modules/hibernate5/src/main/java" charset="UTF-8" />
-    <file url="file://$PROJECT_DIR$/persistence-modules/hibernate5/src/main/resources" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/persistence-modules/spring-data-jpa-repo-2/src/main/java" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/persistence-modules/spring-data-jpa-repo-2/src/main/resources" charset="UTF-8" />
     <file url="file://$PROJECT_DIR$/persistence-modules/spring-data-redis/src/main/java" charset="UTF-8" />
diff --git a/.idea/jarRepositories.xml b/.idea/jarRepositories.xml
index 9f239e4965..1067e4c6b5 100644
--- a/.idea/jarRepositories.xml
+++ b/.idea/jarRepositories.xml
@@ -6,16 +6,6 @@
       <option name="name" value="OSSEZ Private Snapshots" />
       <option name="url" value="https://repo.ossez.com/repository/maven-snapshots/" />
     </remote-repository>
-    <remote-repository>
-      <option name="id" value="central" />
-      <option name="name" value="Central Repository" />
-      <option name="url" value="https://repo.maven.apache.org/maven2" />
-    </remote-repository>
-    <remote-repository>
-      <option name="id" value="geodb-repo" />
-      <option name="name" value="GeoDB repository" />
-      <option name="url" value="http://repo.boundlessgeo.com/main/" />
-    </remote-repository>
     <remote-repository>
       <option name="id" value="ossez-repo-releases" />
       <option name="name" value="OSSEZ Private Releases" />
diff --git a/.idea/php.xml b/.idea/php.xml
deleted file mode 100644
index f5f27444bd..0000000000
--- a/.idea/php.xml
+++ /dev/null
@@ -1,12 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="MessDetectorOptionsConfiguration">
-    <option name="transferred" value="true" />
-  </component>
-  <component name="PHPCSFixerOptionsConfiguration">
-    <option name="transferred" value="true" />
-  </component>
-  <component name="PHPCodeSnifferOptionsConfiguration">
-    <option name="transferred" value="true" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/.idea/thriftCompiler.xml b/.idea/thriftCompiler.xml
deleted file mode 100644
index 7bc123c6bc..0000000000
--- a/.idea/thriftCompiler.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="ThriftCompiler">
-    <compilers />
-  </component>
-</project>
\ No newline at end of file
diff --git a/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertToMap/Book.java b/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertToMap/Book.java
deleted file mode 100644
index 847e0bd8cd..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertToMap/Book.java
+++ /dev/null
@@ -1,48 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertToMap/ConvertToMap.java b/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertToMap/ConvertToMap.java
deleted file mode 100644
index 317cdca529..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertToMap/ConvertToMap.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertcollectiontoarraylist/Foo.java b/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertcollectiontoarraylist/Foo.java
deleted file mode 100644
index 5c9464182e..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertcollectiontoarraylist/Foo.java
+++ /dev/null
@@ -1,52 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/Animal.java b/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/Animal.java
deleted file mode 100644
index b8eddf71a5..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/Animal.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/ConvertListToMapService.java b/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/ConvertListToMapService.java
deleted file mode 100644
index 57579e948f..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/ConvertListToMapService.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertToMap/ConvertToMapUnitTest.java b/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertToMap/ConvertToMapUnitTest.java
deleted file mode 100644
index d6eab461d7..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertToMap/ConvertToMapUnitTest.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertcollectiontoarraylist/CollectionToArrayListUnitTest.java b/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertcollectiontoarraylist/CollectionToArrayListUnitTest.java
deleted file mode 100644
index b8134de08a..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertcollectiontoarraylist/CollectionToArrayListUnitTest.java
+++ /dev/null
@@ -1,145 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertiteratortolist/ConvertIteratorToListServiceUnitTest.java b/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertiteratortolist/ConvertIteratorToListServiceUnitTest.java
deleted file mode 100644
index 7d94f88d21..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertiteratortolist/ConvertIteratorToListServiceUnitTest.java
+++ /dev/null
@@ -1,100 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertlisttomap/ConvertListToMapServiceUnitTest.java b/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertlisttomap/ConvertListToMapServiceUnitTest.java
deleted file mode 100644
index 4d783f4525..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertlisttomap/ConvertListToMapServiceUnitTest.java
+++ /dev/null
@@ -1,68 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertlisttomap/ConvertListWithDuplicatedIdToMapServiceUnitTest.java b/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertlisttomap/ConvertListWithDuplicatedIdToMapServiceUnitTest.java
deleted file mode 100644
index 5e6828a3d5..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/convertlisttomap/ConvertListWithDuplicatedIdToMapServiceUnitTest.java
+++ /dev/null
@@ -1,68 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/collections/IterableToCollectionUnitTest.java b/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/collections/IterableToCollectionUnitTest.java
deleted file mode 100644
index 0283191b74..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/collections/IterableToCollectionUnitTest.java
+++ /dev/null
@@ -1,122 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/collections/JavaCollectionConversionUnitTest.java b/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/collections/JavaCollectionConversionUnitTest.java
deleted file mode 100644
index 7947d1b6c7..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/collections/JavaCollectionConversionUnitTest.java
+++ /dev/null
@@ -1,145 +0,0 @@
-package com.baeldung.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/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/lists/ListToStringUnitTest.java b/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/lists/ListToStringUnitTest.java
deleted file mode 100644
index 0fdc096d14..0000000000
--- a/core-java-modules/core-java-collections-conversions/src/test/java/com/baeldung/java/lists/ListToStringUnitTest.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package com.baeldung.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, "|"));
-    }
-}