验证：java 主线程在子线程结束后才会结束

package com.idealisan.test;

/**
 * Hello world!
 *
 */
public class App
{
    public static void main( String[] args )
    {
        System.out.println("a");
        Runnable t=new Runnable() {

            public void run() {
                System.out.println("aa");
                try {
                    System.out.println(Thread.activeCount());
                    Thread.sleep(10000);
                    System.out.println(Thread.activeCount());

                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                System.out.println("bb");
            }
        };
        new Thread(t).start();

        System.out.println("b");
        Thread.currentThread().stop();
        System.out.println("stopped");
    }
}

10秒的睡眠时间绝对可以说明先后顺序了。并且强制stop线程也可以说明语句执行次序。