Java实现指定线程执行顺序的三种方式示例

2019-11-26 09:19:39

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本文实例讲述了Java实现指定线程执行顺序的三种方式。分享给大家供大家参考，具体如下：

方法一：通过共享对象锁加上可见变量来实现。

public class MyService {  private volatile int orderNum = 1;  public synchronized void methodA() {    try {      while (orderNum != 1) {        wait();      }      for (int i = 0; i < 2; i++) {        System.out.println("AAAAA");      }      orderNum = 2;      notifyAll();    } catch (InterruptedException e) {      e.printStackTrace();    }  }  public synchronized void methodB() {    try {      while (orderNum != 2) {        wait();      }      for (int i = 0; i < 2; i++) {        System.out.println("BBBBB");      }      orderNum = 3;      notifyAll();    } catch (InterruptedException e) {      e.printStackTrace();    }  }  public synchronized void methodC() {    try {      while (orderNum != 3) {        wait();      }      for (int i = 0; i < 2; i++) {        System.out.println("CCCCC");      }      orderNum = 1;      notifyAll();    } catch (InterruptedException e) {      e.printStackTrace();    }  }}

import service.MyService;public class ThreadAA extends Thread {  private MyService dbtools;  public ThreadAA(MyService dbtools) {    super();    this.dbtools = dbtools;  }  @Override  public void run() {    dbtools.methodA();  }}

import service.MyService;public class ThreadBB extends Thread {  private MyService dbtools;  public ThreadBB(MyService dbtools) {    super();    this.dbtools = dbtools;  }  @Override  public void run() {    dbtools.methodB();  }}

import service.MyService;public class ThreadCC extends Thread {  private MyService dbtools;  public ThreadCC(MyService dbtools) {    this.dbtools = dbtools;  }  @Override  public void run() {    dbtools.methodC();  }}

import extthread.ThreadCC;import service.MyService;import extthread.ThreadAA;import extthread.ThreadBB;public class Run {  public static void main(String[] args) {    MyService myService = new MyService();    for (int i = 0; i < 2; i++) {      ThreadBB output = new ThreadBB(myService);      output.start();      ThreadAA input = new ThreadAA(myService);      input.start();      ThreadCC threadCC = new ThreadCC(myService);      threadCC.start();    }  }}

执行结果：

可以看到线程的启动按顺序执行了。共享对象锁，可以保证每个方法只能同时有一个线程进入，配合wait和notifyall方法，可以启动或者唤醒线程。

方法二：通过主线程Join()

class T11 extends Thread {  public void run() {    System.out.println("in T1");  }}class T22 extends Thread {  public void run() {    System.out.println("in T2");  }}class T33 extends Thread {  public void run() {    System.out.println("in T3");  }}public class Test2 {  public static void main(String[] args) throws InterruptedException {    T11 t1 = new T11();    T22 t2 = new T22();    T33 t3 = new T33();    t1.start();    t1.join();    t2.start();    t2.join();    t3.start();  }}

方法三：通过线程执行时Join()

class T1 extends Thread {  public void run(){    Random random = new Random();    try {      Thread.sleep(random.nextInt(1000));    } catch (InterruptedException e) {      e.printStackTrace();    }    System.out.println("in T1");  }}class T2 extends Thread{  private Thread thread;  public T2(Thread thread) {    this.thread = thread;  }  public void run(){    try {      thread.join();    } catch (InterruptedException e) {      e.printStackTrace();    }    System.out.println("in T2");  }}class T3 extends Thread{  private Thread thread;  public T3(Thread thread) {    this.thread = thread;  }  public void run(){    try {      thread.join();    } catch (InterruptedException e) {      e.printStackTrace();    }    System.out.println("in T3");  }}public class Test {  public static void main(String[] args) throws InterruptedException {    T1 t1 = new T1();    T2 t2 = new T2(t1);    T3 t3 = new T3(t2);    t2.start();    t1.start();    t3.start();  }}

更多java相关内容感兴趣的读者可查看本站专题：《Java进程与线程操作技巧总结》、《Java数据结构与算法教程》、《Java操作DOM节点技巧总结》、《Java文件与目录操作技巧汇总》和《Java缓存操作技巧汇总》

希望本文所述对大家java程序设计有所帮助。

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