Fixed the "Comparator and Comparable in Java" Article

alimate · alimate · commit 163ff6d2f27c · 2020-08-12T01:23:02.000+04:30
diff --git a/core-java-modules/core-java-lang/src/main/java/com/baeldung/comparable/Player.java b/core-java-modules/core-java-lang/src/main/java/com/baeldung/comparable/Player.java
@@ -45,7 +45,7 @@ public String toString() {
 
     @Override
     public int compareTo(Player otherPlayer) {
-        return (this.getRanking() - otherPlayer.getRanking());
+        return Integer.compare(getRanking(), otherPlayer.getRanking());
     }
 
 }
diff --git a/core-java-modules/core-java-lang/src/main/java/com/baeldung/comparator/PlayerAgeComparator.java b/core-java-modules/core-java-lang/src/main/java/com/baeldung/comparator/PlayerAgeComparator.java
@@ -6,7 +6,7 @@ public class PlayerAgeComparator implements Comparator<Player> {
 
     @Override
     public int compare(Player firstPlayer, Player secondPlayer) {
-       return (firstPlayer.getAge() - secondPlayer.getAge());
+       return Integer.compare(firstPlayer.getAge(), secondPlayer.getAge());
     }
 
 }
diff --git a/core-java-modules/core-java-lang/src/main/java/com/baeldung/comparator/PlayerRankingComparator.java b/core-java-modules/core-java-lang/src/main/java/com/baeldung/comparator/PlayerRankingComparator.java
@@ -6,7 +6,7 @@ public class PlayerRankingComparator implements Comparator<Player> {
 
     @Override
     public int compare(Player firstPlayer, Player secondPlayer) {
-       return (firstPlayer.getRanking() - secondPlayer.getRanking());
+       return Integer.compare(firstPlayer.getRanking(), secondPlayer.getRanking());
     }
 
 }
diff --git a/core-java-modules/core-java-lang/src/test/java/com/baeldung/comparator/AvoidingSubtractionUnitTest.java b/core-java-modules/core-java-lang/src/test/java/com/baeldung/comparator/AvoidingSubtractionUnitTest.java
@@ -0,0 +1,26 @@
+package com.baeldung.comparator;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+public class AvoidingSubtractionUnitTest {
+
+    @Test
+    public void givenTwoPlayers_whenUsingSubtraction_thenOverflow() {
+        Comparator<Player> comparator = (p1, p2) -> p1.getRanking() - p2.getRanking();
+        Player player1 = new Player(59, "John", Integer.MAX_VALUE);
+        Player player2 = new Player(67, "Roger", -1);
+
+        List<Player> players = Arrays.asList(player1, player2);
+        players.sort(comparator);
+        System.out.println(players);
+
+        assertEquals("John", players.get(0).getName());
+        assertEquals("Roger", players.get(1).getName());
+    }
+}
diff --git a/core-java-modules/core-java-lang/src/test/java/com/baeldung/comparator/Java8ComparatorUnitTest.java b/core-java-modules/core-java-lang/src/test/java/com/baeldung/comparator/Java8ComparatorUnitTest.java
@@ -1,14 +1,14 @@
 package com.baeldung.comparator;
 
-import static org.junit.Assert.assertEquals;
+import org.junit.Before;
+import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
-import org.junit.Before;
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
 
 public class Java8ComparatorUnitTest {
 
@@ -28,7 +28,7 @@ public void setUp() {
     @Test
     public void whenComparing_UsingLambda_thenSorted() {
         System.out.println("************** Java 8 Comaparator **************");
-        Comparator<Player> byRanking = (Player player1, Player player2) -> player1.getRanking() - player2.getRanking();
+        Comparator<Player> byRanking = (Player player1, Player player2) -> Integer.compare(player1.getRanking(), player2.getRanking());
 
         System.out.println("Before Sorting : " + footballTeam);
         Collections.sort(footballTeam, byRanking);

Original file line number	Diff line number	Diff line change
`@@ -45,7 +45,7 @@ public String toString() {`
`45`	`45`
`46`	`46`	`@Override`
`47`	`47`	`public int compareTo(Player otherPlayer) {`
`48`		`- return (this.getRanking() - otherPlayer.getRanking());`
	`48`	`+ return Integer.compare(getRanking(), otherPlayer.getRanking());`
`49`	`49`	`}`
`50`	`50`
`51`	`51`	`}`
Original file line number	Diff line number	Diff line change
`@@ -6,7 +6,7 @@ public class PlayerAgeComparator implements Comparator<Player> {`
`6`	`6`
`7`	`7`	`@Override`
`8`	`8`	`public int compare(Player firstPlayer, Player secondPlayer) {`
`9`		`- return (firstPlayer.getAge() - secondPlayer.getAge());`
	`9`	`+ return Integer.compare(firstPlayer.getAge(), secondPlayer.getAge());`
`10`	`10`	`}`
`11`	`11`
`12`	`12`	`}`
Original file line number	Diff line number	Diff line change
`@@ -6,7 +6,7 @@ public class PlayerRankingComparator implements Comparator<Player> {`
`6`	`6`
`7`	`7`	`@Override`
`8`	`8`	`public int compare(Player firstPlayer, Player secondPlayer) {`
`9`		`- return (firstPlayer.getRanking() - secondPlayer.getRanking());`
	`9`	`+ return Integer.compare(firstPlayer.getRanking(), secondPlayer.getRanking());`
`10`	`10`	`}`
`11`	`11`
`12`	`12`	`}`