/**
* @author LiHaitao
* @description Th:
* @date 2019/1/28 15:30
**/
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Java程序演示如何在Java和Java中使用notify和notifyAll方法
*如何通知和notifyAll方法通知线程，哪个线程被唤醒等。
*/
public class NotificationTest {
private volatile boolean go = false;
public static void main(String args[]) throws InterruptedException {
final NotificationTest test = new NotificationTest();
Runnable waitTask = new Runnable(){
@Override
public void run(){
try {
test.shouldGo();
} catch (InterruptedException ex) {
Logger.getLogger(NotificationTest.class.getName()).
log(Level.SEVERE, null, ex);
}
System.out.println(Thread.currentThread() + " finished Execution");
}
};
Runnable notifyTask = new Runnable(){
@Override
public void run(){
test.go();
System.out.println(Thread.currentThread() + " finished Execution");
}
};
Thread t1 = new Thread(waitTask, "WT1"); //will wait
Thread t2 = new Thread(waitTask, "WT2"); //will wait
Thread t3 = new Thread(waitTask, "WT3"); //will wait
Thread t4 = new Thread(notifyTask,"NT1"); //will notify
//starting all waiting thread
t1.start();
t2.start();
t3.start();
//pause to ensure all waiting thread started successfully
Thread.sleep(200);
//starting notifying thread
t4.start();
}
/*
* wait and notify can only be called from synchronized method or bock
*/
private synchronized void shouldGo() throws InterruptedException {
while(go != true){
System.out.println(Thread.currentThread()
+ " is going to wait on this object");
wait(); //release lock and reacquires on wakeup
System.out.println(Thread.currentThread() + " is woken up");
}
go = false; //resetting condition
}
/*
* both shouldGo() and go() are locked on current object referenced by "this" keyword
*/
private synchronized void go() {
while (go == false){
System.out.println(Thread.currentThread()
+ " is going to notify all or one thread waiting on this object");
go = true; //making condition true for waiting thread
//notify(); // only one out of three waiting thread WT1, WT2,WT3 will woke up
notifyAll(); // all waiting thread WT1, WT2,WT3 will woke up
}
}
}
