Java 學習筆記之 安全執行緒

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安全執行緒:

 

安全執行緒的方法一定是排隊啟動並執行。

public class SyncObject {    synchronized public void methodA() {        try {            System.out.println("begin methodA threadName = " +                    Thread.currentThread().getName());            Thread.sleep(5000);            System.out.println("end");        } catch (InterruptedException e) {            e.printStackTrace();        }    }}public class SyncThreadA extends Thread{    private SyncObject object;    public SyncThreadA(SyncObject object) {        this.object = object;    }    @Override    public void run() {        super.run();        object.methodA();    }}public class SyncThreadB extends Thread{    private SyncObject object;    public SyncThreadB(SyncObject object) {        this.object = object;    }    @Override    public void run() {        super.run();        object.methodA();    }}public class ThreadRunMain {    public static void main(String[] args) {        testSyncThread();    }    public static void testSyncThread(){        SyncObject object = new SyncObject();        SyncThreadA a = new SyncThreadA(object);        a.setName("A");        SyncThreadB b = new SyncThreadB(object);        b.setName("B");        a.start();        b.start();    }}

運行結果：

如果去掉synchronized，運行結果：

 

Java 學習筆記之 安全執行緒