[BAEL-9550] - Moved articles and codes from core-java-collections module to java-collections-convversions and java-collections-maps module

java-collections-conversions/src/main/java/com/baeldung/convertcollectiontoarraylist/Foo.java

@@ -0,0 +1,52 @@
+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);
+    }
+
+}

java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/Animal.java

@@ -0,0 +1,27 @@
+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;
+    }
+}

java-collections-conversions/src/main/java/com/baeldung/convertlisttomap/ConvertListToMapService.java

@@ -0,0 +1,42 @@
+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.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, animal -> animal));
+        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;
+    }
+}

java-collections-conversions/src/main/resources/logback.xml

@@ -0,0 +1,13 @@
+<?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>