java中线程的使用(未完)

来源：互联网发布：伯爵和唯一视觉知乎编辑：程序博客网时间：2024/06/04 18:17

简单的使用线程

1 . 扩展java.lang.Thread类

/***定义线程类*/public class MyThread extends Thread {  　　public void run() {  　　 System.out.println("MyThread.run()");  　　}  }

//使用线程MyThread myThread1 = new MyThread();  MyThread myThread2 = new MyThread();  myThread1.start();  myThread2.start();

2 . 实现java.lang.Runnable接口

/** * 实现Runnable接口的类*/ publicclass DoSomethingimplements Runnable {    private String name;    public DoSomething(String name) {        this.name = name;    }     publicvoid run() {        for (int i = 0; i < 5; i++) {            for (long k = 0; k < 100000000; k++) ;            System.out.println(name + ": " + i);        }     } }

/** * 测试Runnable类实现的多线程程序*/ publicclass TestRunnable {    publicstaticvoid main(String[] args) {        DoSomething ds1 = new DoSomething("阿三");        DoSomething ds2 = new DoSomething("李四");        Thread t1 = new Thread(ds1);        Thread t2 = new Thread(ds2);        t1.start();         t2.start();     } }

线程的同步与锁

线程的同步是为了防止多个线程访问一个数据对象时，对数据造成的破坏。
例如：两个线程ThreadA、ThreadB都操作同一个对象Foo对象，并修改Foo对象上的数据。

public class Foo {    privateint x = 100;    publicint getX() {        return x;    }     publicint fix(int y) {        x = x - y;         return x;    } }

public class MyRunnable implements Runnable {    private Foo foo =new Foo();     public staticvoid main(String[] args) {        MyRunnable r = new MyRunnable();        Thread ta = new Thread(r,"Thread-A");         Thread tb = new Thread(r,"Thread-B");         ta.start();         tb.start();     }     public void run() {        for (int i = 0; i < 3; i++) {            this.fix(30);            try {                Thread.sleep(1);             } catch (InterruptedException e) {                e.printStackTrace();             }             System.out.println(Thread.currentThread().getName() + " :当前foo对象的x值= " + foo.getX());        }     }     publicint fix(int y) {        return foo.fix(y);    } }

运行结果：

Thread-B :当前foo对象的x值= 40Thread-A :当前foo对象的x值= 40Thread-B :当前foo对象的x值= -20Thread-A :当前foo对象的x值= -20Thread-B :当前foo对象的x值= -80Thread-A :当前foo对象的x值= -80

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