@@ -9,30 +9,35 @@
 
 public class IdGenerator3 {
 
-    private static volatile IdGenerator3 idGenerator3 = null;
+    private static volatile IdGenerator3 instance = null;
 
-    private IdGenerator3() {
+    private int generatorId = 0;
+
+    private IdGenerator3(){
 
     }
 
-    public static IdGenerator3 getInstance() {
-        if (idGenerator3 == null) {
-            synchronized (IdGenerator3.class) {
-                if (idGenerator3 == null) {
-                    idGenerator3 = new IdGenerator3();
+    public static IdGenerator3 getInstance(){
+        if (instance == null){
+            synchronized (IdGenerator3.class){
+                if (instance == null){
+                    instance = new IdGenerator3();
                 }
             }
         }
-        return idGenerator3;
+        return instance;
     }
 
-    public int getId() {
-        return 1;
+    public int getGeneratorId(){
+        return generatorId++;
     }
 
-    // TODO Testing...
+
     public static void main(String[] args) {
-        IdGenerator3 idGenerator3 = IdGenerator3.getInstance();
-        System.out.println(idGenerator3.getId());
+        for (int i = 0; i < 10; i++) {
+            System.out.println(IdGenerator3.getInstance().getGeneratorId());
+        }
+
     }
+
 }
Original file line number	Diff line number	Diff line change
`@@ -9,30 +9,35 @@`
`9`	`9`
`10`	`10`	`public class IdGenerator3 {`
`11`	`11`
`12`		`- private static volatile IdGenerator3 idGenerator3 = null;`
	`12`	`+ private static volatile IdGenerator3 instance = null;`
`13`	`13`
`14`		`- private IdGenerator3() {`
	`14`	`+ private int generatorId = 0;`
	`15`	`+`
	`16`	`+ private IdGenerator3(){`
`15`	`17`
`16`	`18`	`}`
`17`	`19`
`18`		`- public static IdGenerator3 getInstance() {`
`19`		`- if (idGenerator3 == null) {`
`20`		`- synchronized (IdGenerator3.class) {`
`21`		`- if (idGenerator3 == null) {`
`22`		`- idGenerator3 = new IdGenerator3();`
	`20`	`+ public static IdGenerator3 getInstance(){`
	`21`	`+ if (instance == null){`
	`22`	`+ synchronized (IdGenerator3.class){`
	`23`	`+ if (instance == null){`
	`24`	`+ instance = new IdGenerator3();`
`23`	`25`	`}`
`24`	`26`	`}`
`25`	`27`	`}`
`26`		`- return idGenerator3;`
	`28`	`+ return instance;`
`27`	`29`	`}`
`28`	`30`
`29`		`- public int getId() {`
`30`		`- return 1;`
	`31`	`+ public int getGeneratorId(){`
	`32`	`+ return generatorId++;`
`31`	`33`	`}`
`32`	`34`
`33`		`- // TODO Testing...`
	`35`	`+`
`34`	`36`	`public static void main(String[] args) {`
`35`		`- IdGenerator3 idGenerator3 = IdGenerator3.getInstance();`
`36`		`- System.out.println(idGenerator3.getId());`
	`37`	`+ for (int i = 0; i < 10; i++) {`
	`38`	`+ System.out.println(IdGenerator3.getInstance().getGeneratorId());`
	`39`	`+ }`
	`40`	`+`
`37`	`41`	`}`
	`42`	`+`
`38`	`43`	`}`