public class ConnThreadLocal {
public static ThreadLocal<String> th = new ThreadLocal<String>();
public void setTh(String value){
th.set(value);
}
public void getTh(){
System.out.println(Thread.currentThread().getName() + ":" + this.th.get());
}
public static void main(String[] args) throws InterruptedException {
final ConnThreadLocal ct = new ConnThreadLocal();
Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
ct.setTh("张三");
ct.getTh();
}
}, "t1");
Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(1000);
ct.getTh();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "t2");
t1.start();
t2.start();
}
}
public class Singletion {
private static class InnerSingletion {
private static Singletion single = new Singletion();
}
public static Singletion getInstance(){
return InnerSingletion.single;
}
}
public class DubbleSingleton {
private static DubbleSingleton ds;
public static DubbleSingleton getDs(){
if(ds == null){
try {
//模拟初始化对象的准备时间...
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();
}
}