废话不多说,代码走起
package com.zhku.thread;
public class TestThread {
//阻塞
public synchronized static void test() throws InterruptedException {
for (int i=0; i<100; i++) {
Thread.sleep(1000);
System.out.println(i);
}
}
//阻塞
public static void test1() throws InterruptedException {
synchronized (TestThread.class) {
for (int i = 0; i < 100; i++) {
Thread.sleep(1000);
System.out.println(i);
}
}
}
//阻塞
public void test2() throws InterruptedException {
synchronized (TestThread.class) {
for (int i = 0; i < 100; i++) {
Thread.sleep(1000);
System.out.println(i);
}
}
}
//相同对象阻塞,对象不相同不阻塞
public void test3() throws InterruptedException {
synchronized (this) {
for (int i = 0; i < 100; i++) {
Thread.sleep(1000);
System.out.println(i);
}
}
}
//相同对象阻塞,对象不相同不阻塞
public synchronized void test4() throws InterruptedException {
for (int i = 0; i < 100; i++) {
Thread.sleep(1000);
System.out.println(i);
}
}
public static void main(String[] args) {
// TestThread thread = new TestThread(); 在外面定义,每个线程的对象相同
TestThread thread = new TestThread();
for (int i=0; i<3; i++) {
new Thread(()->{
try {
// new TestThread().test();在循环里,每个线程的对象不相同
thread.test();//现在是同一个对象调用
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}).start();;
}
}
}
总结:
- synchronized在普通方法上,会锁住同一对象的调用
- synchronized在静态方法上,会锁住
- synchronized (this)同步块的作用跟在普通方法上一样,都会锁住同一对象的调用
- synchronized (xxx.class)同步块的作用跟在静态方法上一样,都会锁住