打断 sleep，wait，join 的线程
这几个方法都会让线程进入阻塞状态
打断 sleep 的线程, 会清空打断状态，以 sleep 为例
private static void test1() throws InterruptedException {
Thread t1 = new Thread(()->{
sleep(1);
}, "t1");
t1.start();
sleep(0.5);
t1.interrupt();
log.debug(" 打断状态: {}", t1.isInterrupted());
}输出
java.lang.InterruptedException: sleep interrupted
at java.lang.Thread.sleep(Native Method)
at java.lang.Thread.sleep(Thread.java:340)
at java.util.concurrent.TimeUnit.sleep(TimeUnit.java:386)
at cn.itcast.n2.util.Sleeper.sleep(Sleeper.java:8)
at cn.itcast.n4.TestInterrupt.lambda$test1$3(TestInterrupt.java:59)
at java.lang.Thread.run(Thread.java:745)
21:18:10.374 [main] c.TestInterrupt - 打断状态: false打断正常运行的线程
打断正常运行的线程, 不会清空打断状态
private static void test2() throws InterruptedException {
Thread t2 = new Thread(()->{
while(true) {
Thread current = Thread.currentThread();
boolean interrupted = current.isInterrupted();
if(interrupted) {
log.debug(" 打断状态: {}", interrupted);
break;
}
}
}, "t2");
t2.start();
sleep(0.5);
t2.interrupt();
}输出
20:57:37.964 [t2] c.TestInterrupt - 打断状态: true两阶段终止模式
利用 isInterrupted
interrupt 可以打断正在执行的线程，无论这个线程是在 sleep，wait，还是正常运行
class TPTInterrupt {
private Thread thread;
public void start(){
thread = new Thread(() -> {
while(true) {
Thread current = Thread.currentThread();
if(current.isInterrupted()) {
log.debug("料理后事");
break;
}
try {
Thread.sleep(1000);
log.debug("将结果保存");
} catch (InterruptedException e) {
current.interrupt()
// 执行监控操作
}
},"监控线程");
thread.start();
}
public void stop() {
thread.interrupt();
}
}调用
TPTInterrupt t = new TPTInterrupt();
t.start();
Thread.sleep(3500);
log.debug("stop");
t.stop();结果
11:49:42.915 c.TwoPhaseTermination [监控线程] - 将结果保存
11:49:43.919 c.TwoPhaseTermination [监控线程] - 将结果保存
11:49:44.919 c.TwoPhaseTermination [监控线程] - 将结果保存
11:49:45.413 c.TestTwoPhaseTermination [main] - stop
11:49:45.413 c.TwoPhaseTermination [监控线程] - 料理后事利用停止标记
// 停止标记用 volatile 是为了保证该变量在多个线程之间的可见性
// 我们的例子中，即主线程把它修改为 true 对 t1 线程可见
class TPTVolatile {
private Thread thread;
private volatile boolean stop = false;
public void start(){
thread = new Thread(() -> {
while(true) {
Thread current = Thread.currentThread();
if(stop) {
log.debug("料理后事");
break;
}
try {
Thread.sleep(1000);
log.debug("将结果保存");
} catch (InterruptedException e) { }
// 执行监控操作
}
},"监控线程");
thread.start();
}
public void stop() {
stop = true;
thread.interrupt();
}
}调用
TPTVolatile t = new TPTVolatile();
t.start();
Thread.sleep(3500);
log.debug("stop");
t.stop();结果
11:54:52.003 c.TPTVolatile [监控线程] - 将结果保存
11:54:53.006 c.TPTVolatile [监控线程] - 将结果保存
11:54:54.007 c.TPTVolatile [监控线程] - 将结果保存
11:54:54.502 c.TestTwoPhaseTermination [main] - stop
11:54:54.502 c.TPTVolatile [监控线程] - 料理后事打断 park 线程
打断 park 线程, 不会清空打断状态
private static void test3() throws InterruptedException {
Thread t1 = new Thread(() -> {
log.debug("park...");
LockSupport.park();
log.debug("unpark...");
log.debug("打断状态：{}", Thread.currentThread().isInterrupted());
}, "t1");
t1.start();
sleep(0.5);
t1.interrupt();
}输出
21:11:52.795 [t1] c.TestInterrupt - park...
21:11:53.295 [t1] c.TestInterrupt - unpark...
21:11:53.295 [t1] c.TestInterrupt - 打断状态：true如果打断标记已经是 true, 则 park 会失效
private static void test4() {
Thread t1 = new Thread(() -> {
for (int i = 0; i < 5; i++) {
log.debug("park...");
LockSupport.park();
log.debug("打断状态：{}", Thread.currentThread().isInterrupted());
}
});
t1.start();
sleep(1);
t1.interrupt();
}输出
21:13:48.783 [Thread-0] c.TestInterrupt - park...
21:13:49.809 [Thread-0] c.TestInterrupt - 打断状态：true
21:13:49.812 [Thread-0] c.TestInterrupt - park...
21:13:49.813 [Thread-0] c.TestInterrupt - 打断状态：true
21:13:49.813 [Thread-0] c.TestInterrupt - park...
21:13:49.813 [Thread-0] c.TestInterrupt - 打断状态：true
21:13:49.813 [Thread-0] c.TestInterrupt - park...
21:13:49.813 [Thread-0] c.TestInterrupt - 打断状态：true
21:13:49.813 [Thread-0] c.TestInterrupt - park...
21:13:49.813 [Thread-0] c.TestInterrupt - 打断状态：true提示
可以使用 Thread.interrupted() 清除打断状态
