synchronized关键字的用法

1、class monitor

public synchronized static void staticSync()synchronized (ClassMonitor.class)

2、this monitor

public synchronized void sync()synchronized (this)

3、monitor

private final Object object= new Object();
synchronized (object)

使用举例

1、类锁

// 类锁 class
public void method_class() {try {System.out.println(Thread.currentThread().getName() + "  方法开始");synchronized (Service.class) {extracted();}System.out.println(Thread.currentThread().getName() + "  方法结束");} catch (InterruptedException e) {e.printStackTrace();}
}// 类锁 static syn
public static synchronized void method_syn_static() {try {System.out.println(Thread.currentThread().getName() + "  方法开始");extracted();System.out.println(Thread.currentThread().getName() + "  方法结束");} catch (InterruptedException e) {e.printStackTrace();}
}

2、对象锁

// 对象锁 synchronized
public synchronized void method_syn() {try {System.out.println(Thread.currentThread().getName() + "  方法开始");extracted();System.out.println(Thread.currentThread().getName() + "  方法结束");} catch (InterruptedException e) {e.printStackTrace();}
}// 对象锁 this
public void method_this() {try {System.out.println(Thread.currentThread().getName() + "  方法开始");synchronized (this) {extracted();}System.out.println(Thread.currentThread().getName() + "  方法结束");} catch (InterruptedException e) {e.printStackTrace();}
}

3、私有锁

private String lock = new String();// 私有锁
public void method_pri_lock() {try {System.out.println(Thread.currentThread().getName() + "  方法开始");synchronized (lock) {extracted();}System.out.println(Thread.currentThread().getName() + "  方法结束");} catch (InterruptedException e) {e.printStackTrace();}
}// 局部私有锁
public void method_loc_lock() {try {System.out.println(Thread.currentThread().getName() + "  方法开始");String lock = new String();synchronized (lock) {extracted();}System.out.println(Thread.currentThread().getName() + "  方法结束");} catch (InterruptedException e) {e.printStackTrace();}
}