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摘要: 线程基础---wait(),notify的应用一例
本例子实现了两个线程,每个线程输出1到100的数字。 第一个线程输出1-10,停止,通知第二个线程 输出1-10 第二个线程停止 通知第一个线程 输出11-20 ... 实现的要点是 在Java中,每个对象都有个对象锁标志(Object lock flag)与之想关联,当一个线程A调用对象的一段synchronized代码时, 它首先要获取与这个对象关联的对象锁标志,然后执行相应的代码,执行结束后,把这个对象锁标志返回给对象;因此,在线程A执行 synchronized代码期间,如果另一个线程B也要执行同一对象的一段synchronized代码时(不一定与线程A执行的相同),它将 要等到线程A执行完后,才能继续.... 如何利用wait() notify() notifyAll()? 在synchronized代码被执行期间,线程可以调用对象的wait()方法,释放对象锁标志,进入等待状态,并且可以调用notify()或者 notifyAll()方法通知正在等待的其他线程。notify()通知等待队列中的第一个线程,notifyAll()通知的是等待队列中的所有线程。 /** * Title: Jasons's Java Projdect * Copyright: Copyright (c) ChinaJavaLab * Company: http://www.ChinaJavaLab.com * @author jason jason@ChinaJavaLab.com * @version 1.0 */ import java.lang.Runnable; import java.lang.Thread; public class DemoThread implements Runnable{ public DemoThread() { TestThread testthread1 = new TestThread(this,"1"); TestThread testthread2 = new TestThread(this,"2"); testthread2.start(); testthread1.start(); } public static void main(String[] args) { DemoThread demoThread1 = new DemoThread(); } public void run(){ TestThread t = (TestThread) Thread.currentThread(); try{ if (!t.getName().equalsIgnoreCase("1")) { synchronized(this) { wait(); } } while(true){ System.out.println("@time in thread"+ t.getName()+ "="+ t.increaseTime()); if(t.getTime()%10 == 0) { synchronized(this) { System.out.println("****************************************"); notify(); if ( t.getTime()==100 ) break; wait(); } } } }catch(Exception e){e.printStackTrace();} } } class TestThread extends Thread{ private int time = 0 ; public TestThread(Runnable r,String name){ super(r,name); } public int getTime(){ return time; } public int increaseTime (){ return ++time; } } 程序运行结果:
C:\java>java DemoThread
@time in thread1=1
@time in thread1=2
@time in thread1=3
@time in thread1=4
@time in thread1=5
@time in thread1=6
@time in thread1=7
@time in thread1=8
@time in thread1=9
@time in thread1=10
****************************************
@time in thread2=1
@time in thread2=2
@time in thread2=3
@time in thread2=4
@time in thread2=5
@time in thread2=6
@time in thread2=7
@time in thread2=8
@time in thread2=9
@time in thread2=10
****************************************
@time in thread1=11
@time in thread1=12
@time in thread1=13
@time in thread1=14
@time in thread1=15
@time in thread1=16
@time in thread1=17
@time in thread1=18
@time in thread1=19
@time in thread1=20
****************************************
@time in thread2=11
@time in thread2=12
@time in thread2=13
@time in thread2=14
@time in thread2=15
@time in thread2=16
@time in thread2=17
@time in thread2=18
@time in thread2=19
@time in thread2=20
****************************************
@time in thread1=21
@time in thread1=22
@time in thread1=23
@time in thread1=24
@time in thread1=25
@time in thread1=26
@time in thread1=27
@time in thread1=28
@time in thread1=29
@time in thread1=30
****************************************
@time in thread2=21
@time in thread2=22
@time in thread2=23
@time in thread2=24
@time in thread2=25
@time in thread2=26
@time in thread2=27
@time in thread2=28
@time in thread2=29
@time in thread2=30
****************************************
@time in thread1=31
@time in thread1=32
@time in thread1=33
@time in thread1=34
@time in thread1=35
@time in thread1=36
@time in thread1=37
@time in thread1=38
@time in thread1=39
@time in thread1=40
****************************************
@time in thread2=31
@time in thread2=32
@time in thread2=33
@time in thread2=34
@time in thread2=35
@time in thread2=36
@time in thread2=37
@time in thread2=38
@time in thread2=39
@time in thread2=40
****************************************
@time in thread1=41
@time in thread1=42
@time in thread1=43
@time in thread1=44
@time in thread1=45
@time in thread1=46
@time in thread1=47
@time in thread1=48
@time in thread1=49
@time in thread1=50
****************************************
@time in thread2=41
@time in thread2=42
@time in thread2=43
@time in thread2=44
@time in thread2=45
@time in thread2=46
@time in thread2=47
@time in thread2=48
@time in thread2=49
@time in thread2=50
****************************************
@time in thread1=51
@time in thread1=52
@time in thread1=53
@time in thread1=54
@time in thread1=55
@time in thread1=56
@time in thread1=57
@time in thread1=58
@time in thread1=59
@time in thread1=60
****************************************
@time in thread2=51
@time in thread2=52
@time in thread2=53
@time in thread2=54
@time in thread2=55
@time in thread2=56
@time in thread2=57
@time in thread2=58
@time in thread2=59
@time in thread2=60
****************************************
@time in thread1=61
@time in thread1=62
@time in thread1=63
@time in thread1=64
@time in thread1=65
@time in thread1=66
@time in thread1=67
@time in thread1=68
@time in thread1=69
@time in thread1=70
****************************************
@time in thread2=61
@time in thread2=62
@time in thread2=63
@time in thread2=64
@time in thread2=65
@time in thread2=66
@time in thread2=67
@time in thread2=68
@time in thread2=69
@time in thread2=70
****************************************
@time in thread1=71
@time in thread1=72
@time in thread1=73
@time in thread1=74
@time in thread1=75
@time in thread1=76
@time in thread1=77
@time in thread1=78
@time in thread1=79
@time in thread1=80
****************************************
@time in thread2=71
@time in thread2=72
@time in thread2=73
@time in thread2=74
@time in thread2=75
@time in thread2=76
@time in thread2=77
@time in thread2=78
@time in thread2=79
@time in thread2=80
****************************************
@time in thread1=81
@time in thread1=82
@time in thread1=83
@time in thread1=84
@time in thread1=85
@time in thread1=86
@time in thread1=87
@time in thread1=88
@time in thread1=89
@time in thread1=90
****************************************
@time in thread2=81
@time in thread2=82
@time in thread2=83
@time in thread2=84
@time in thread2=85
@time in thread2=86
@time in thread2=87
@time in thread2=88
@time in thread2=89
@time in thread2=90
****************************************
@time in thread1=91
@time in thread1=92
@time in thread1=93
@time in thread1=94
@time in thread1=95
@time in thread1=96
@time in thread1=97
@time in thread1=98
@time in thread1=99
@time in thread1=100
****************************************
@time in thread2=91
@time in thread2=92
@time in thread2=93
@time in thread2=94
@time in thread2=95
@time in thread2=96
@time in thread2=97
@time in thread2=98
@time in thread2=99
@time in thread2=100
****************************************
C:\java>
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