Java multi-thread join

Java multi-thread join

Code first

Create a Thread with the following code:

 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 }

Then create a new test class. The Code is as follows:

Package com. thread. test;/** 0-50 executes the main thread, 50-executes the thread, the main thread */public class ThreadDemo {public static void main (String [] args) will be executed after thread A is fully executed) {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 ("main thread" + "[" + I + "]") ;}}

The following is an explanation of the Join method in Thread in Java Platform SE8 API:

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.

Code first

Create a Thread with the following code:

 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 }

Then create a new test class. The Code is as follows:

Package com. thread. test;/** 0-50 executes the main thread, 50-executes the thread, the main thread */public class ThreadDemo {public static void main (String [] args) will be executed after thread A is fully executed) {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 ("main thread" + "[" + I + "]") ;}}

The following is an explanation of the Join method in Thread in Java Platform SE8 API:

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.

My own understanding is that it will forcibly enter the thread using the join method. Other threads will not come in until the thread is fully executed.