Merge pull request #37 from amitrp/aph-15276_difference_between_two_Lists

aph-15276 difference between two lists

Author: amitrp

README.md

@@ -115,6 +115,7 @@ This project contains Core Java code samples that are used as examples on [amitp
 
 ### [Asserting Java Lists for Equality Ignoring the Order](https://www.amitph.com/java-assert-lists-equals-ignore-order/)
 
+### [Finding the Differences Between Two Java Lists](https://www.amitph.com/java-find-lists-difference/)
 
 ## How to use
 *Clone the project using*

java-collections/README.md

@@ -78,6 +78,8 @@ This project contains Java Collections code samples that are used as examples on
 
 ### [Asserting Java Lists for Equality Ignoring the Order](https://www.amitph.com/java-assert-lists-equals-ignore-order/)
 
+### [Finding the Differences Between Two Java Lists](https://www.amitph.com/java-find-lists-difference/)
+
 ## How to use
 *Clone the project using*
 ```
@@ -87,6 +89,3 @@ This project contains Java Collections code samples that are used as examples on
 ```
 ~ cd java-collections/
 ```
-
-
-

…/java/collections/list/Deduplicator.java …a/collections/list/ListDeduplicator.javajava-collections/src/main/java/com/amitph/java/collections/list/Deduplicator.java renamed to java-collections/src/main/java/com/amitph/java/collections/list/ListDeduplicator.java java-collections/src/main/java/com/amitph/java/collections/list/Deduplicator.java renamed to java-collections/src/main/java/com/amitph/java/collections/list/ListDeduplicator.java

@@ -4,7 +4,7 @@
 import java.util.LinkedHashSet;
 import java.util.List;
 
-public class Deduplicator {
+public class ListDeduplicator {
     public <T> List<T> usingStreamDistinct(List<T> list) {
         return list.stream()
                 .distinct()
@@ -16,7 +16,7 @@ public <T> List<T> usingJavaSet(List<T> list) {
     }
 
     public static void main(String[] ar) {
-        Deduplicator deduplicator = new Deduplicator();
+        ListDeduplicator deduplicator = new ListDeduplicator();
 
         System.out.println("Remove duplicates from list: using Streams distinct()");
         deduplicator.usingStreamDistinct(List.of(1, 2, 4, 2, 1, 4, 2, 5, 6, 4))

…h/java/collections/list/Partitioner.java …va/collections/list/ListPartitioner.javajava-collections/src/main/java/com/amitph/java/collections/list/Partitioner.java renamed to java-collections/src/main/java/com/amitph/java/collections/list/ListPartitioner.java java-collections/src/main/java/com/amitph/java/collections/list/Partitioner.java renamed to java-collections/src/main/java/com/amitph/java/collections/list/ListPartitioner.java

@@ -9,7 +9,7 @@
 import java.util.List;
 import java.util.stream.IntStream;
 
-public class Partitioner {
+public class ListPartitioner {
     public <T> List<List<T>> partitionListUsingGuava(List<T> list, int size) {
         return Lists.partition(list, size);
     }
@@ -45,7 +45,7 @@ public <T> List<List<T>> partitionListUsingPlainJava(List<T> list, int size) {
     }
 
     public static void main(String[] a) {
-        Partitioner partitioner = new Partitioner();
+        ListPartitioner partitioner = new ListPartitioner();
 
         System.out.println("Partition a Java List: Using Guava");
         List<Integer> list = IntStream.rangeClosed(1, 21).boxed().toList();

java-collections/src/main/java/com/amitph/java/collections/list/ListsDifferenceFinder.java

@@ -0,0 +1,78 @@
+package com.amitph.java.collections.list;
+
+import com.google.common.collect.Sets;
+import org.apache.commons.collections4.CollectionUtils;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+public class ListsDifferenceFinder {
+
+    private final List<String> one = List.of("Ray", "Tim", "Leo", "Bee", "Tim");
+    private final List<String> two = List.of("Ray", "Mia", "Lyn", "Bee", "Zoe", "Mia");
+
+    public void usingPlainJava() {
+        System.out.println("The first List minus the second List");
+        List<String> difference = new ArrayList<>(one);
+        difference.removeAll(two);
+
+        System.out.println(difference);
+
+        System.out.println("The second List minus the first List");
+        difference = new ArrayList<>(two);
+        difference.removeAll(one);
+
+        System.out.println(difference);
+    }
+
+    public void usingStreams() {
+        System.out.println("The first List minus the second List");
+        List<String> difference = one.stream()
+                .filter(e -> !two.contains(e))
+                .toList();
+        System.out.println(difference);
+
+        System.out.println("The second List minus the first List");
+        difference = two.stream()
+                .filter(e -> !one.contains(e))
+                .toList();
+        System.out.println(difference);
+    }
+
+    public void usingApacheCommons() {
+        System.out.println("The first List minus the second List");
+        List<String> differences = new ArrayList<>(CollectionUtils.removeAll(one, two));
+        System.out.println(differences);
+
+        System.out.println("The second List minus the first List");
+        differences = new ArrayList<>((CollectionUtils.removeAll(two, one)));
+        System.out.println(differences);
+    }
+
+    public void usingGuava() {
+        Set<String> differences = Sets.difference(new HashSet<>(two), new HashSet<>(one));
+        System.out.println(differences);
+    }
+
+
+    public static void main(String[] a) {
+        ListsDifferenceFinder differenceFinder = new ListsDifferenceFinder();
+
+        System.out.println("Using Plain Java:");
+        differenceFinder.usingPlainJava();
+
+        System.out.println();
+        System.out.println("Using Java Streams:");
+        differenceFinder.usingStreams();
+
+        System.out.println();
+        System.out.println("Using Apache Commons Collection:");
+        differenceFinder.usingApacheCommons();
+
+        System.out.println();
+        System.out.println("Using Guava:");
+        differenceFinder.usingGuava();
+    }
+}