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premaseempremaseem
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Bonus pattern example pushed for Singleton pattern
1 parent e4a7f81 commit e46538e

11 files changed

Lines changed: 356 additions & 13 deletions

‎patternBonus/src/com/premaseem/Client.java‎

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This file was deleted.

‎patternBonus/src/com/premaseem/singleton/ClientForSingletonEagerInstance.java‎

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package com.premaseem.singleton;
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import java.util.Scanner;
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public class ClientForSingletonEagerInstance {
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public static void main(String[] args) {
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Scanner scan = new Scanner(System.in);
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int repeatRunFlag = 1;
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while (repeatRunFlag == 1) {
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System.out.println("This is the Client Main Singleton eager instance ");
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SingletonEagerInstance.uniqueInstance.doCounting();
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SingletonEagerInstance.uniqueInstance.doCounting();
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SingletonEagerInstance.uniqueInstance.doCounting();
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System.out.println("\n $$$$$$$$$$$$$$$$$$$$ Thanks by Prem Aseem $$$$$$$$$$$$$$$$$$$$$$ \n ");
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System.out.println("Do you want to Re-run this program - Press 1 for yes and 0 or other digits to EXIT ");
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try{
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repeatRunFlag = scan.nextInt();
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}catch(Exception e){
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repeatRunFlag = 0;
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}
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}
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}
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}

‎patternBonus/src/com/premaseem/singleton/ClientForSingletonLazyInstance.java‎

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package com.premaseem.singleton;
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import java.util.Scanner;
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public class ClientForSingletonLazyInstance {
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public static void main(String[] args) {
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Scanner scan = new Scanner(System.in);
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int repeatRunFlag = 1;
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while (repeatRunFlag == 1) {
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System.out.println("This is the Client Main Singleton Lazy instance, that means the instance would be created on need basis ");
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SingletonLazyInstance instance = SingletonLazyInstance.getInstance();
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instance.doCounting();
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instance.doCounting();
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instance.doCounting();
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System.out.println("\n $$$$$$$$$$$$$$$$$$$$ Thanks by Prem Aseem $$$$$$$$$$$$$$$$$$$$$$ \n ");
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System.out.println("Do you want to Re-run this program - Press 1 for yes and 0 or other digits to EXIT ");
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try{
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repeatRunFlag = scan.nextInt();
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}catch(Exception e){
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repeatRunFlag = 0;
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}
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}
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}
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}

‎patternBonus/src/com/premaseem/singleton/ClientForSingletonThreadDoubleLock.java‎

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package com.premaseem.singleton;
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import java.util.Scanner;
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public class ClientForSingletonThreadDoubleLock {
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public static void main(String[] args) {
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Scanner scan = new Scanner(System.in);
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int repeatRunFlag = 1;
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while (repeatRunFlag == 1) {
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System.out.println("This is the Client Main Singleton Thread issue, there is a fair chance of multiple instiances creation by multiple threads ");
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Thread thread1 = new Thread() {
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public void run() {
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System.out.println("Thread1 Running");
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SingletonDoubleLock.getInstance().doCounting();
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}
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};
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thread1.start();
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Thread thread2 = new Thread() {
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public void run() {
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System.out.println("Thread2 Running");
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SingletonDoubleLock.getInstance().doCounting();
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}
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};
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thread2.start();
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Thread thread3 = new Thread() {
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public void run() {
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System.out.println("Thread3 Running");
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SingletonDoubleLock.getInstance().doCounting();
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}
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};
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thread3.start();
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System.out.println("\n $$$$$$$$$$$$$$$$$$$$ Thanks by Prem Aseem $$$$$$$$$$$$$$$$$$$$$$ \n ");
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System.out.println("Do you want to Re-run this program - Press 1 for yes and 0 or other digits to EXIT ");
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try {
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repeatRunFlag = scan.nextInt();
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} catch (Exception e) {
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repeatRunFlag = 0;
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}
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}
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}
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}

‎patternBonus/src/com/premaseem/singleton/ClientForSingletonThreadIssue.java‎

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package com.premaseem.singleton;
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import java.util.Scanner;
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public class ClientForSingletonThreadIssue {
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public static void main(String[] args) {
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Scanner scan = new Scanner(System.in);
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int repeatRunFlag = 1;
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while (repeatRunFlag == 1) {
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System.out.println("This is the Client Main Singleton Thread issue, there is a fair chance of multiple instiances creation by multiple threads ");
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Thread thread1 = new Thread() {
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public void run() {
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System.out.println("Thread1 Running");
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SingletonThreadissueInstance.getInstance().doCounting();
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;
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}
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};
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thread1.start();
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Thread thread2 = new Thread() {
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public void run() {
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System.out.println("Thread2 Running");
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SingletonThreadissueInstance.getInstance().doCounting();
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}
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};
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thread2.start();
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Thread thread3 = new Thread() {
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public void run() {
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System.out.println("Thread3 Running");
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SingletonThreadissueInstance.getInstance().doCounting();
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;
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}
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};
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thread3.start();
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System.out.println("\n $$$$$$$$$$$$$$$$$$$$ Thanks by Prem Aseem $$$$$$$$$$$$$$$$$$$$$$ \n ");
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System.out.println("Do you want to Re-run this program - Press 1 for yes and 0 or other digits to EXIT ");
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try {
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repeatRunFlag = scan.nextInt();
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} catch (Exception e) {
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repeatRunFlag = 0;
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}
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}
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}
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}

‎patternBonus/src/com/premaseem/singleton/ClientForSingletonThreadSyncIssue.java‎

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package com.premaseem.singleton;
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import java.util.Scanner;
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public class ClientForSingletonThreadSyncIssue {
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public static void main(String[] args) {
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Scanner scan = new Scanner(System.in);
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int repeatRunFlag = 1;
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while (repeatRunFlag == 1) {
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System.out.println("This is the Client Main Singleton Thread issue, there is a fair chance of multiple instiances creation by multiple threads ");
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Thread thread1 = new Thread() {
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public void run() {
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System.out.println("Thread1 Running");
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SingletonSyncInstance.getInstance().doCounting();
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;
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}
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};
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thread1.start();
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Thread thread2 = new Thread() {
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public void run() {
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System.out.println("Thread2 Running");
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SingletonSyncInstance.getInstance().doCounting();
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}
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};
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thread2.start();
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Thread thread3 = new Thread() {
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public void run() {
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System.out.println("Thread3 Running");
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SingletonSyncInstance.getInstance().doCounting();
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;
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}
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};
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thread3.start();
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System.out.println("\n $$$$$$$$$$$$$$$$$$$$ Thanks by Prem Aseem $$$$$$$$$$$$$$$$$$$$$$ \n ");
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System.out.println("Do you want to Re-run this program - Press 1 for yes and 0 or other digits to EXIT ");
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try {
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repeatRunFlag = scan.nextInt();
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} catch (Exception e) {
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repeatRunFlag = 0;
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}
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}
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}
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}

‎patternBonus/src/com/premaseem/singleton/SingletonDoubleLock.java‎

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package com.premaseem.singleton;
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public class SingletonDoubleLock {
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// Have a private constructor so that it cannot be instanciate other then
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// from this class.
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private SingletonDoubleLock() {
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}
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public static volatile SingletonDoubleLock uniqueInstance = null;
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public static final SingletonDoubleLock getInstance() {
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if (uniqueInstance == null) {
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synchronized (SingletonDoubleLock.class) {
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try {
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Thread.sleep(10000);
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if (uniqueInstance == null) {
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System.out.println("Creating the instance for first and only time ");
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uniqueInstance = new SingletonDoubleLock();
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}
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} catch (InterruptedException e) {
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// TODO Auto-generated catch block
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e.printStackTrace();
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}
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}
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}
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return uniqueInstance;
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}
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public int stateholder = 1;
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public void doCounting() {
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System.out.println("Each time this method is called, it current state would get incremanted by 5");
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for (int i = 1; i <= 5; i++, stateholder++)
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System.out.println("Count is " + stateholder);
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}
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}

‎patternBonus/src/com/premaseem/singleton/SingletonEagerInstance.java‎

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package com.premaseem.singleton;
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public class SingletonEagerInstance {
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// Have a private constructor so that it cannot be instanciate other then
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// from this class.
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private SingletonEagerInstance() {
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}
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public static final SingletonEagerInstance uniqueInstance = new SingletonEagerInstance();
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public int stateholder = 1;
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public void doCounting() {
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System.out.println("Each time this method is called, it current state would get incremanted by 5");
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for (int i = 1; i <= 5; i++,stateholder++)
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System.out.println("Count is " + stateholder);
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}
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}

‎patternBonus/src/com/premaseem/singleton/SingletonLazyInstance.java‎

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package com.premaseem.singleton;
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public class SingletonLazyInstance {
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// Have a private constructor so that it cannot be instanciate other then
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// from this class.
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private SingletonLazyInstance() {
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}
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public static SingletonLazyInstance uniqueInstance = null;
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public static final SingletonLazyInstance getInstance(){
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if(uniqueInstance == null){
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System.out.println("Creating the instance for first and only time ");
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uniqueInstance = new SingletonLazyInstance();
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}
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return uniqueInstance;
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}
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public int stateholder = 1;
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public void doCounting() {
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System.out.println("Each time this method is called, it current state would get incremanted by 5");
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for (int i = 1; i <= 5; i++,stateholder++)
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System.out.println("Count is " + stateholder);
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}
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}

‎patternBonus/src/com/premaseem/singleton/SingletonSyncInstance.java‎

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package com.premaseem.singleton;
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public class SingletonSyncInstance {
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// Have a private constructor so that it cannot be instanciate other then
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// from this class.
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private SingletonSyncInstance() {
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}
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public static SingletonSyncInstance uniqueInstance = null;
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public static final synchronized SingletonSyncInstance getInstance() {
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if (uniqueInstance == null) {
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try {
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Thread.sleep(10000);
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System.out.println("Creating the instance for first and only time ");
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uniqueInstance = new SingletonSyncInstance();
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} catch (InterruptedException e) {
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// TODO Auto-generated catch block
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e.printStackTrace();
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}
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}
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return uniqueInstance;
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}
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public int stateholder = 1;
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public void doCounting() {
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System.out.println("Each time this method is called, it current state would get incremanted by 5");
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for (int i = 1; i <= 5; i++, stateholder++)
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System.out.println("Count is " + stateholder);
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}
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}

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