锁的使用_java_示例代码

一：synchronized示例

　　1、主类

package locks;

/**
 * @author chunxiaozhang
 * @date 2020/4/9 10:06
 * @desc
 */
public class MainDemo {

    public static void main(String[] args) {
        final Peopele p = new Peopele ();
        final Peopele p2 = new Peopele ();
        //线程1
        new Thread ( new Runnable ( ) {
            @Override
            public void run() {
                p2.speak_obj ();;
            }
        } ,"thread_1").start();
        //线程2
        new Thread ( new Runnable ( ) {
            @Override
            public void run() {
                p.speak_static_void();
            }
        } ,"thread_2").start();
        //线程3
        new Thread ( new Runnable ( ) {
            @Override
            public void run() {
                p.speak_static_void ();
            }
        } ,"thread_3").start();
    }
}

　　2、测试类

package locks;

/**
 * @author chunxiaozhang
 * @date 2020/4/9 11:05
 * @desc
 */
public class  Peopele {

    private static int sta_num = 1;
    private int num = 1;

    //无锁部分
    public void speak() {
        System.out.println ( Thread.currentThread ().getName () + ":开始。。。。。。。。。。" );
        try {
            Thread.sleep ( 1000 );
            System.out.println ( Thread.currentThread ().getName () + ":sta_num+1=" + (sta_num+1));
            System.out.println ( Thread.currentThread ().getName () + ":num+1=" + (num+1));
        } catch (InterruptedException e) {
            e.printStackTrace ( );
        }
        System.out.println ( Thread.currentThread ().getName () + ":结束。。。。。。。。。。" );
    }

    //用于对象上
    public void speak_this() {
        synchronized (this) {
            System.out.println ( Thread.currentThread ().getName () + ":开始。。。。。。。。。。" );
            try {
                Thread.sleep ( 3000 );
            } catch (InterruptedException e) {
                e.printStackTrace ( );
            }
            System.out.println ( Thread.currentThread ().getName () + ":结束。。。。。。。。。。" );
        }
    }

    //用于类上
    public void speak_class() {
        synchronized (Peopele.class) {
            System.out.println ( Thread.currentThread ().getName () + ":开始。。。。。。。。。。" );
            try {
                Thread.sleep ( 3000 );
            } catch (InterruptedException e) {
                e.printStackTrace ( );
            }
            System.out.println ( Thread.currentThread ().getName () + ":结束。。。。。。。。。。" );
        }
    }

    //用于任意对象
    public  void speak_obj() {
        synchronized (new Object ()) {
            System.out.println ( Thread.currentThread ().getName () + ":开始。。。。。。。。。。" );
            try {
                Thread.sleep ( 3000 );
            } catch (InterruptedException e) {
                e.printStackTrace ( );
            }
            System.out.println ( Thread.currentThread ().getName () + ":结束。。。。。。。。。。" );
        }
    }

    //用于方法上
    public synchronized void speak_void() {
        System.out.println ( Thread.currentThread ().getName () + ":开始。。。。。。。。。。" );
        try {
            Thread.sleep ( 3000 );
        } catch (InterruptedException e) {
            e.printStackTrace ( );
        }
        System.out.println ( Thread.currentThread ().getName () + ":结束。。。。。。。。。。" );
    }
    
    //用于静态方法上
    public synchronized static void speak_static_void() {
        System.out.println ( Thread.currentThread ().getName () + ":开始。。。。。。。。。。" );
        try {
            Thread.sleep ( 3000 );
        } catch (InterruptedException e) {
            e.printStackTrace ( );
        }
        System.out.println ( Thread.currentThread ().getName () + ":结束。。。。。。。。。。" );
    }
}