Java多线程中关于join方法的使用实例解析

package com.thread.test;public class MyThread extends Thread {  private String name;  public MyThread(String name) {    this.name = name;  }  @Override  public void run() {    for (int i = 0; i < 100; i++) {      System.out.println(name+"["+i+"]");    }    super.run();  }}

package com.thread.test;/* * 0-50执行的是主线程,50-100执行的是A线程,并且将A线程完全执行完后才继续执行主线程 */public class ThreadDemo{  public static void main(String[] args) {    MyThread t = new MyThread("A");    t.start();    for (int i = 0; i < 100; i++) {      if (i>50) {        try {          t.join();        } catch (InterruptedException e) {          e.printStackTrace();        }      }      System.out.println("主线程"+"["+i+"]");    }  }}

public final void join(long millis)        throws InterruptedExceptionWaits at most millis milliseconds for this thread to die. A timeout of 0 means to wait forever. This implementation uses a loop of this.wait calls conditioned on this.isAlive. As a thread terminates the this.notifyAll method is invoked. It is recommended that applications not use wait, notify, or notifyAll on Thread instances.Parameters: millis - the time to wait in milliseconds Throws: IllegalArgumentException - if the value of millis is negative InterruptedException - if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown.

package com.thread.test;public class MyThread extends Thread {  private String name;  public MyThread(String name) {    this.name = name;  }  @Override  public void run() {    for (int i = 0; i < 100; i++) {      System.out.println(name+"["+i+"]");    }    super.run();  }}

package com.thread.test;/* * 0-50执行的是主线程,50-100执行的是A线程,并且将A线程完全执行完后才继续执行主线程 */public class ThreadDemo{  public static void main(String[] args) {    MyThread t = new MyThread("A");    t.start();    for (int i = 0; i < 100; i++) {      if (i>50) {        try {          t.join();        } catch (InterruptedException e) {          e.printStackTrace();        }      }      System.out.println("主线程"+"["+i+"]");    }  }}

public final void join(long millis)        throws InterruptedExceptionWaits at most millis milliseconds for this thread to die. A timeout of 0 means to wait forever. This implementation uses a loop of this.wait calls conditioned on this.isAlive. As a thread terminates the this.notifyAll method is invoked. It is recommended that applications not use wait, notify, or notifyAll on Thread instances.Parameters: millis - the time to wait in milliseconds Throws: IllegalArgumentException - if the value of millis is negative InterruptedException - if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown.