java线程例子

以下是一些java线程的小李子，欢迎大家讨论

第一个例子：线程的interrupt方法的使用

package threadtest;

public class Thread1 extends Thread {

	private boolean stop = false;

	public static void main(String args[]) throws Exception {

		Thread1 thread = new Thread1();

		System.out.println("Starting thread...");

		thread.start();

		Thread.sleep(3000);

		System.out.println("Interrupting thread..."); // 这种方法并不会中断一个正在运行的线程

		thread.interrupt();

		Thread.sleep(3000);

		System.out.println("Stopping application...");

		System.exit(0);

	}

	public void run() {

		while (!stop) {

			System.out.println("Thread is running...");

			long time = System.currentTimeMillis();

			while ((System.currentTimeMillis() - time < 1000) && (!stop)) {

			}

		}

	}
}

执行结果：
Starting thread...
Thread is running...
Thread is running...
Thread is running...
Thread is running...
Interrupting thread...
Thread is running...
Thread is running...
Thread is running...
Stopping application...
第二个例子：   stop

package threadtest;

public class Thread2 extends Thread {
	volatile boolean stop = false;

	  public static void main( String args[] ) throws Exception {

		  Thread2 thread = new Thread2();

	   System.out.println( "Starting thread..." );

	   thread.start();

	   Thread.sleep( 3000 );

	   System.out.println( "Asking thread to stop..." );

	   thread.stop = true; //真的停止了

	   Thread.sleep( 3000 );

	   System.out.println( "Stopping application..." );

	   System.exit( 0 );

	  }

	  public void run() {

	    while ( !stop ) {

	     System.out.println( "Thread is running..." );

	      long time = System.currentTimeMillis();

	      while ( (System.currentTimeMillis()-time < 1000) && (!stop) ) {

	      }

	    }

	   System.out.println( "Thread exiting under request..." );

	  }
}

执行结果；
Starting thread...
Thread is running...
Thread is running...
Thread is running...
Asking thread to stop...
Thread exiting under request...
Stopping application...

第三个例子：  正确的停止线程方式是设置共享变量，并调用interrupt()（注意变量应该先设置）。如果线程没有被阻塞，
这时调用interrupt()将不起作用；否则，线程就将得到异常（该线程必须事先预备好处理此状况），接着逃离阻塞状态。
在任何一种情况中，最后线程都将检查共享变量然后再停止。Listing C这个示例描述了该技术。

package threadtest;

public class Thread3 extends Thread {
	volatile boolean stop = false;

	  public static void main( String args[] ) throws Exception {

		  Thread3 thread = new Thread3();

	   System.out.println( "Starting thread..." );

	   thread.start();

	   Thread.sleep( 3000 );

	   System.out.println( "Asking thread to stop..." );

	   thread.stop = true;

	   thread.interrupt(); //停止了再阻断会有异常发生

	   Thread.sleep( 3000 );

	   System.out.println( "Stopping application..." );

	   System.exit( 0 );

	  }

	  public void run() {

	    while ( !stop ) {

	     System.out.println( "Thread running..." );

	      try {

	      Thread.sleep( 1000 );

	      } catch ( InterruptedException e ) {

	      System.out.println( "Thread interrupted..." );

	      }

	    }

	   System.out.println( "Thread exiting under request..." );
	  }
}

Starting thread...
Thread running...
Thread running...
Thread running...
Asking thread to stop...
Thread interrupted...
Thread exiting under request...
Stopping application...

第四个例子：

package multithread;

public class Test extends Thread{
    public static void main(String argv[])
    {
    	Test b = new Test();
        b.run();
    }
    public void start() //start方法才是启动线程的方法,一般不需要重写start方法，重写run方法即可
    {
       for (int i = 0; i <10; i++){
           System.out.println("Value of i = " + i);
       }
    }
}

执行结果，没有任何输出，因为线程只有调用start方法才进入运行状态

第五个例子：wait的使用

package multithread;

public class Agg {
	public static void main(String argv[]) {
		Agg a = new Agg();
		a.go();
	}

	public void go() {
		DSRoss ds1 = new DSRoss("one");
		ds1.start();
	}
}

class DSRoss extends Thread {
	private String sTname = "";

	DSRoss(String s) {
		sTname = s;
	}

	public void run() {
		notwait();
		System.out.println("finished");
	}

	public void notwait() {
		while (true) {
			try {
				System.out.println("waiting");
				wait();
			} catch (InterruptedException ie) {
			}
			System.out.println(sTname);
			notifyAll();
		}
	}
}

出现异常：
Exception in thread "Thread-0" java.lang.IllegalMonitorStateException
waiting
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:485)
at multithread.DSRoss.notwait(Agg.java:31)
at multithread.DSRoss.run(Agg.java:23)

join的使用：

class MyThread extends Thread{
	public void run(){
		for(int i=0;i<20;i++){
			System.out.println("lala"+this.getName());
		}
	}
}
public class Test {

	public static void main(String[] args) throws InterruptedException {
		
		MyThread t = new MyThread();
		t.start();
//		t.join();
		
		System.out.println(Double.NaN>5);
		System.out.println("lala");
		
	
		
	}

}

当没有t.join();时，主线程和线程的执行顺序是不一定的，但有了t.join();
之后，会保证t先执行完在执行main线程
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
lalaThread-0
false
lala