1. Java 8 Comparators example added

2. Comparator.comparing example added

core-java/src/test/java/com/baeldung/comparable/ComparableUnitTest.java

@@ -20,8 +20,10 @@ public class ComparableUnitTest {
         footballTeam.add(player2);
         footballTeam.add(player3);
         Collections.sort(footballTeam);
-        assertEquals(footballTeam.get(0).getName(), "Steven");
+        assertEquals(footballTeam.get(0)
-        assertEquals(footballTeam.get(2).getRanking(), 67);
+            .getName(), "Steven");
+        assertEquals(footballTeam.get(2)
+            .getRanking(), 67);
     }
 
 }

core-java/src/test/java/com/baeldung/comparator/ComparatorUnitTest.java

@@ -14,7 +14,7 @@ public class ComparatorUnitTest {
     List<Player> footballTeam;
 
     @Before
-    public void setUp(){
+    public void setUp() {
         footballTeam = new ArrayList<Player>();
         Player player1 = new Player(59, "John", 20);
         Player player2 = new Player(67, "Roger", 22);
@@ -28,16 +28,20 @@ public class ComparatorUnitTest {
     public void whenUsingRankingComparator_thenSortedList() {
         PlayerRankingComparator playerComparator = new PlayerRankingComparator();
         Collections.sort(footballTeam, playerComparator);
-        assertEquals(footballTeam.get(0).getName(), "Steven");
+        assertEquals(footballTeam.get(0)
-        assertEquals(footballTeam.get(2).getRanking(), 67);
+            .getName(), "Steven");
+        assertEquals(footballTeam.get(2)
+            .getRanking(), 67);
     }
 
     @Test
     public void whenUsingAgeComparator_thenSortedList() {
         PlayerAgeComparator playerComparator = new PlayerAgeComparator();
         Collections.sort(footballTeam, playerComparator);
-        assertEquals(footballTeam.get(0).getName(), "John");
+        assertEquals(footballTeam.get(0)
-        assertEquals(footballTeam.get(2).getRanking(), 45);
+            .getName(), "John");
+        assertEquals(footballTeam.get(2)
+            .getRanking(), 45);
     }
 
 }

core-java/src/test/java/com/baeldung/comparator/Java8ComparatorUnitTest.java

@@ -0,0 +1,63 @@
+package com.baeldung.comparator;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class Java8ComparatorUnitTest {
+
+    List<Player> footballTeam;
+
+    @Before
+    public void setUp() {
+        footballTeam = new ArrayList<Player>();
+        Player player1 = new Player(59, "John", 20);
+        Player player2 = new Player(67, "Roger", 22);
+        Player player3 = new Player(45, "Steven", 24);
+        footballTeam.add(player1);
+        footballTeam.add(player2);
+        footballTeam.add(player3);
+    }
+
+    @Test
+    public void whenComparing_UsingJava8_thenSorted() {
+        System.out.println("************** Java 8 Comaparator **************");
+        Comparator<Player> byRanking = new Comparator<Player>() {
+
+            @Override
+            public int compare(Player player1, Player player2) {
+                return player1.getRanking() - player2.getRanking();
+            }
+        };
+
+        System.out.println("Before Sorting : " + footballTeam);
+        Collections.sort(footballTeam, byRanking);
+        System.out.println("After Sorting : " + footballTeam);
+        assertEquals(footballTeam.get(0)
+            .getName(), "Steven");
+        assertEquals(footballTeam.get(2)
+            .getRanking(), 67);
+    }
+
+    @Test
+    public void whenComparing_UsingComparatorComparing_thenSorted() {
+        System.out.println("********* Comaparator.comparing method *********");
+        Comparator<Player> byRanking =
+            (Player player1, Player player2)->player1.getRanking()-player2.getRanking();
+
+        System.out.println("Before Sorting : " + footballTeam);
+        Collections.sort(footballTeam, byRanking);
+        System.out.println("After Sorting : " + footballTeam);
+        assertEquals(footballTeam.get(0)
+            .getName(), "Steven");
+        assertEquals(footballTeam.get(2)
+            .getRanking(), 67);
+    }
+
+}