【多线程】-实现多线程的三种方法

1.第一种是实现 Runnable,并重写run方法

  Thread类中构造方法

/**
 * Allocates a new {@code Thread} object. This constructor has the same
 * effect as {@linkplain #Thread(ThreadGroup,Runnable,String) Thread}
 * {@code (null, target, name)}.
 *
 * @param  target
 *         the object whose {@code run} method is invoked when this thread
 *         is started. If {@code null}, this thread's run method is invoked.
 *
 * @param  name
 *         the name of the new thread
 */
public Thread(Runnable target, String name) {
    init(null, target, name, 0);
}

  

package com.idcos.automate.thread;

import com.idcos.Application;
import org.junit.runner.RunWith;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;

/**
 * @author GuanBin
 * @version ThreadDemo1.java, v1 2018/5/2 下午5:43 GuanBin Exp $$
 */
@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = Application.class)
@WebAppConfiguration
public class ThreadDemo1 implements Runnable {

    private Thread t;

    private String threadName;

//    public ThreadDemo1() {
//
//    }

    public ThreadDemo1(String name) {
        threadName = name;
        System.out.println("Creating threadName" + threadName);
    }

    @Override
    public void run() {

        System.out.println("Running threadName" + threadName);
        try {
            for (int i = 4; i > 0; i--) {
                System.out.println("this thread" + i);
                Thread.sleep(100);
            }

        } catch (InterruptedException e) {
            System.out.println("This thread is Interrupted");
        } catch (Exception e) {
            System.out.println(e);
        }

        System.out.println("Thread is exiting");


    }

    public void start() {
        System.out.println("Starting method name" + threadName);
        if (t == null) {
            t = new Thread(this, threadName);//初始化一个Thread
            t.start();//线程开始
        }
    }

//    @Test
    public  static void main(String[] args) {
        ThreadDemo1 threadDemo1 = new ThreadDemo1("testThread1");
        threadDemo1.start();//调用ThreadDemo1中的start方法

        ThreadDemo1 threadDemo2 = new ThreadDemo1("testThread2");
        threadDemo2.start();
    }
}

输出为：

2.第二种方法是继承Thread类，并重写其run方法，也是必须要调用start方法

其实，本质上也是间接实现了实现了Runnable接口，因为Thread也是实现了Runnable接口

package com.idcos.automate.thread;

/**
 * @author GuanBin
 * @version ThreadDemo2.java, v1 2018/5/3 上午11:14 GuanBin Exp $$
 */
public class ThreadDemo2 extends Thread {

    private Thread t;

    private String threadName;

//    public ThreadDemo1() {
//
//    }

    public ThreadDemo2(String name) {
        threadName = name;
        System.out.println("Creating threadName" + threadName);
    }

    @Override
    public void run() {

        System.out.println("Running threadName" + threadName);
        try {
            for (int i = 4; i > 0; i--) {
                System.out.println("this is " + i);
                Thread.sleep(100);
            }

        } catch (InterruptedException e) {
            System.out.println("This thread is Interrupted");
        } catch (Exception e) {
            System.out.println(e);
        }

        System.out.println("Thread is exiting");


    }

    public void start() {
        System.out.println("Starting method name" + threadName);
        if (t == null) {
            t = new Thread(this, threadName);
            t.start();
        }
    }

    //    @Test
    public  static void main(String[] args) {
        ThreadDemo2 thread1 = new ThreadDemo2("thread1");
        thread1.start();

        ThreadDemo2 thread2 = new ThreadDemo2("thread2");
        thread2.start();
    }
}