java 多线程之主线程与子线程

<span style="font-size:18px;">我们通常在主线程中创建子线程来执行特定任务，那么问题来了，子线程如果未执行完毕，主线程会退出吗？</span></span></span>

<span style="font-size:18px;">带着这个疑问，我们看下面的小demo</span>

public class Main {public Main() {// TODO Auto-generated constructor stub}/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubnew Thread(new Runnable() {public void run() {while (true) {System.out.println("child thread running!");try {Thread.sleep(1000);} catch (InterruptedException e) {}}}}).start();System.out.println("main thread running!");}}

执行结果：

main thread running!

child thread running!
child thread running!
child thread running!
child thread running!
child thread running!
child thread running!
child thread running!
child thread running!

可以看出，子线程还在执行（死循环），主线程已经执行完毕了，但此时进程仍未退出（可以从任务管理器中查看到javaw.exe的进程）。