一：概念
线程通信中经常用到wait和notify，顾名思义，wait即让当前线程处于等待状态，notify通知锁对象
上的另一个线程被唤醒，这里的唤醒是指可以去争夺锁资源，nofityAll是唤醒该对象上面所有处于
wait状态的线程
二：示例
线程t2一运行就处于wait等待状态，然后线程t1运行notify，唤醒线程t2
/**
*
*/
package com.day2; /**
* @author Administrator
*
*/
public class NotifyWaitThreadDemo { private int count; public static void main(String[] args) { NotifyWaitThreadDemo demo = new NotifyWaitThreadDemo(); Thread t1 = new Thread("t1") {
public void run() {
synchronized (demo) {
for (int i = 0; i < 100; i++) {
demo.count = i;
if (demo.count == 50) {
System.out.println(Thread.currentThread().getName()+"发出通知");
demo.notify();
}
}
} }
}; Thread t2 = new Thread("t2") {
public void run() {
while (true) {
synchronized (demo) {
System.out.println(Thread.currentThread().getName() + "开始等待");
try {
demo.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println(Thread.currentThread().getName() + "跳出等待");
System.out.println("demo.count" + demo.count);
break;
} }
}; t2.start();
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
t1.start(); }
}
如果还有一个线程t3也处于wait状态，那么t1线程如果想唤醒t1和t3，就需要使用notifyAll
/**
*
*/
package com.day2; /**
* @author Administrator
*
*/
public class NotifyWaitThreadDemo { private int count; public static void main(String[] args) { NotifyWaitThreadDemo demo = new NotifyWaitThreadDemo(); Thread t1 = new Thread("t1") {
public void run() {
synchronized (demo) {
for (int i = 0; i < 100; i++) {
demo.count = i;
if (demo.count == 50) {
System.out.println(Thread.currentThread().getName()+"发出通知");
//demo.notify();
demo.notifyAll();
}
}
} }
}; Thread t2 = new Thread("t2") {
public void run() {
while (true) {
synchronized (demo) {
System.out.println(Thread.currentThread().getName() + "开始等待");
try {
demo.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println(Thread.currentThread().getName() + "跳出等待");
System.out.println("demo.count" + demo.count);
break;
} }
}; Thread t3 = new Thread("t3") {
public void run() {
while (true) {
synchronized (demo) {
System.out.println(Thread.currentThread().getName() + "开始等待");
try {
demo.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
System.out.println(Thread.currentThread().getName() + "跳出等待");
break;
} }
};
t2.start();
t3.start();
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
t1.start(); }
}
运行结果：
t2开始等待
t3开始等待
t1发出通知
t3跳出等待
t2跳出等待
demo.count99