Join肤浅析

1. join()这个方法是插入到父线程之前执行，此时父线程处于WAITING状态，只有当join的插队线程执行完了，父线程才恢复运行状态！对于同一时刻运行的其他线程，join不起到任何作用！
2. join(long milliseconds,long nanos)：参数指定的时间到达后，唤醒父线程

package mytest;

import java.util.concurrent.TimeUnit;

public class JoinTest {
    static class DataSourcesLoader implements Runnable {

        @Override
        public void run() {
            System.out.println("DataSourcesLoader start...");
            try {
                int i = 0;
                while (i++ < 100) {
                    System.out.println("current thread:" + Thread.currentThread().getName());
                }
                TimeUnit.SECONDS.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("DataSourcesLoader end.");

        }

    }

    static class DataSourcesLoader2 implements Runnable {

        @Override
        public void run() {
            System.out.println("DataSourcesLoader2 start...");
            try {
                int i = 0;
                while (i++ < 100) {
                    System.out.println("current thread:" + Thread.currentThread().getName());
                }
                TimeUnit.SECONDS.sleep(5);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("DataSourcesLoader2 end.");

        }

    }

    public static void main(String[] args) {
        Thread thread = new Thread(new DataSourcesLoader());
        thread.start();
        Thread thread2 = new Thread(new DataSourcesLoader2());
        thread2.start();
        try {
            thread.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println("over");
    }
}