wait() 和notify重温
重温wait()和notify()
温故知新，接下来看看线程池。
同时启动3个线程A、B、C，A线程输出A 20次，B线程输出B 20次，C线程输出C 20次，要求输出结果为顺序输出A、B、C、A、B、C。。。
class Agent{public static int state = 1;public synchronized void sayA() {if(state != 1){try {super.wait();} catch (Exception e) {// TODO: handle exception}}System.out.println("A");state = 2;super.notify();}public synchronized void sayB() {if(state != 2){try {super.wait();} catch (Exception e) {// TODO: handle exception}}System.out.println("B");state = 3;super.notify();}public synchronized void sayC() {if(state != 3){try {super.wait();} catch (Exception e) {// TODO: handle exception}}System.out.println("C");state = 1;super.notify();}}class A extends Thread{Agent agent;public A(Agent agent){this.agent = agent;}public void run(){for(int i=0;i<20;i++){try {Thread.sleep(200);} catch (Exception e) {}agent.sayA();}}}class B extends Thread{Agent agent;public B(Agent agent){this.agent = agent;}public void run(){for(int i=0;i<20;i++){try {Thread.sleep(200);} catch (Exception e) {}agent.sayB();}}}class C extends Thread{Agent agent;public C(Agent agent){this.agent = agent;}public void run(){for(int i=0;i<20;i++){try {Thread.sleep(200);} catch (Exception e) {}agent.sayC();}}}public class TestWait {public static void main(String[] args) {Agent agent = new Agent();new A(agent).start();new B(agent).start();new C(agent).start();}}