package com.bjsxt.base.conn011;
/**
* The first way to write multi-threaded single column is the simplest.
* @author Administrator
*
*/
public class InnerSingleton {
private static class Singletion {
private static Singletion single = new Singletion();
}
public static Singletion getInstance(){
return Singletion.single;
}
}
package com.bjsxt.base.conn011;
/**
* @author Administrator
*The second way of writing multi-threaded single-column mode, two if judgments
*/
public class DubbleSingleton {
private static DubbleSingleton ds;
public static DubbleSingleton getDs(){
if(ds == null){
try {
// Simulate the preparation time of the initialized object...
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace ();
}
synchronized (DubbleSingleton.class) {
if(ds == null){
ds = new DubbleSingleton();
}
}
}
return ds;
}
public static void main(String[] args) {
Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
System.out.println(DubbleSingleton.getDs().hashCode());
}
},"t1");
Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
System.out.println(DubbleSingleton.getDs().hashCode());
}
},"t2");
Thread t3 = new Thread(new Runnable() {
@Override
public void run() {
System.out.println(DubbleSingleton.getDs().hashCode());
}
},"t3");
t1.start();
t2.start();
t3.start();
}
}
package com.bjsxt.base.conn011;
//Ordinary single-column mode multiple threads will create multiple objects
public class Singleton {
private static Singleton s = null;
private void Singleton(){
}
public static Singleton getS(){
if(s == null){
try {
// Simulate the preparation time of the initialized object...
Thread.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace ();
}
s = new Singleton();
}
return s;
}
public static void main(String[] args) {
new Thread(new Runnable() {
@Override
public void run() {
System.out.println(Singleton.getS().hashCode());
}
},"t1").start();
new Thread(new Runnable() {
@Override
public void run() {
System.out.println(Singleton.getS().hashCode());
}
},"t2").start();
new Thread(new Runnable() {
@Override
public void run() {
System.out.println(Singleton.getS().hashCode());
}
},"t3").start();
}
}