淺談Java多線程中的join方法，淺談java多線程join

淺談Java多線程中的join方法，淺談java多線程join

先上代碼

建立一個Thread,代碼如下:

 1 package com.thread.test; 2  3 public class MyThread extends Thread { 4     private String name; 5     public MyThread(String name) { 6         this.name = name; 7     } 8     @Override 9     public void run() {10         for (int i = 0; i < 100; i++) {11             System.out.println(name+"["+i+"]");12         }13         super.run();14     }15 }

之後建立測試類別,代碼如下:

package com.thread.test;/* * 0-50執行的是主線程,50-100執行的是A線程,並且將A線程完全執行完後才繼續執行主線程 */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("主線程"+"["+i+"]");        }    }}

下面是Java Platform SE8 API中對Thread中Join方法的解釋:

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.

先上代碼

建立一個Thread,代碼如下:

 1 package com.thread.test; 2  3 public class MyThread extends Thread { 4     private String name; 5     public MyThread(String name) { 6         this.name = name; 7     } 8     @Override 9     public void run() {10         for (int i = 0; i < 100; i++) {11             System.out.println(name+"["+i+"]");12         }13         super.run();14     }15 }

之後建立測試類別,代碼如下:

package com.thread.test;/* * 0-50執行的是主線程,50-100執行的是A線程,並且將A線程完全執行完後才繼續執行主線程 */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("主線程"+"["+i+"]");        }    }}

下面是Java Platform SE8 API中對Thread中Join方法的解釋:

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.

 我自己的理解就是會強行進入使用join方法的線程，其他線程等待該線程完全執行完後才會進來。