在Java中,synchronized是用来表示同步的,我们可以synchronized来修饰一个方法。也可以synchronized来修饰方法里面的一个语句块。
在static方法前加synchronizedstatic:静态方法属于类方法,它属于这个类,获取到的锁,是属于类的锁。
在普通方法前加synchronizedstatic:非static方法获取到的锁,是属于当前对象的锁。
结论:类锁和对象锁不同,他们之间不会产生互斥。
看一个Demo:
public class SynchoronizedDemo {
//synchronized修饰非静态方法
public synchronized void function() throws InterruptedException {
for (int i = 0; i <3; i++) {
Thread.sleep(1000);
System.out.println("function running...");
}
}
//synchronized修饰静态方法
public static synchronized void staticFunction()
throws InterruptedException {
for (int i = 0; i < 3; i++) {
Thread.sleep(1000);
System.out.println("Static function running...");
}
}
public static void main(String[] args) {
final SynchoronizedDemo demo = new SynchoronizedDemo();
Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
try {
staticFunction();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
try {
demo.function();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
t1.start();
t2.start();
}
}
运行结果:Static function running...
function running...
function running...
Static function running...
Static function running...
function running...