线程同步问题

如果你有三个线程，分别为T1,T2,T3,如何让线程T2在线程T1之后执行，在线程T3之前执行

import java.util.concurrent.atomic.AtomicInteger; /** * Hello world! * */ public class App { private static AtomicInteger i = new AtomicInteger(1); public static void main(String[] args) { Thread t1 = new Thread(new Runnable() { @Override public void run() { synchronized (i) { while(i.get()!=1) { try { i.notifyAll(); i.wait(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } try { Thread.sleep(1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } i.incrementAndGet(); System.out.println("T1====:i="+i ); i.notify(); } } },"THREAD 1"); Thread t2 = new Thread(new Runnable() { @Override public void run() { synchronized (i) { while(i.get()!=2) { try { i.notifyAll(); i.wait(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } try { Thread.sleep(1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } i.incrementAndGet(); System.out.println("T2====:i="+i); i.notify(); } } },"THREAD 2"); Thread t3 = new Thread(new Runnable() { @Override public void run() { synchronized (i) { while(i.get()!=3) { try { i.notifyAll(); i.wait(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } try { Thread.sleep(1000); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } i.incrementAndGet(); System.out.println("T3====:i="+i); i.notify(); } } },"THREAD 3"); t3.start(); t1.start(); t2.start(); } }