1.使用线程的stop()来中断线程
2.使用线程的interrupt()来中断线程
3.通过共享变量来控制
这种方式是直接调用线程的stop()方法，可以直接让线程终止运行，是一种很暴力的方式。
public static void test02(){
Thread thread1 = new Thread(()->{
System.out.println("thread1启动了");
while (true){
System.out.println("thread1循环中...");
}
});
thread1.start();
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("准备关闭thread1线程");
thread1.stop();
System.out.println("主线程停止");
}
运行结果如下
public static void testInterrupt(){
Thread thread1 = new Thread(() -> {
while (true){
boolean interrupted = Thread.currentThread().isInterrupted();
if(interrupted){
System.out.println("thread1线程被中断");
break;
}
System.out.println("thread1循环中...");
}
});
thread1.start();
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
thread1.interrupt();
}
运行结果如下
interrupt相比于stop中断线程的方式更加温柔，当主线程调用thread1线程的interrupt方法其实本质就是将thread1线程的中断标志设置为true,仅此而已。被设置中断标志的线程还是可以继续运行的，不受影响，也就是如果thread不主动结束线程该线程是不会停止的。
代码演示如下
public static void testInterrupt2(){
Thread thread1 = new Thread(() -> {
while (true){
boolean interrupted = Thread.currentThread().isInterrupted();
System.out.println("当前中断标志位状态为："+interrupted);
System.out.println("thread1循环中...");
}
});
thread1.start();
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
thread1.interrupt();
}
运行结果如下
当调用了thread1.interrupt();之后thread1还会一直无限执行下去。
如果thread1线程处于被阻塞状态（例如处于sleep,wait,join等状态），在别的线程调用thread1的interrupt方法，那么线程的中断状态会被清除，并抛出InterruptedException异常
代码如下
public static void testInterrupt3(){
Thread thread1 = new Thread(() -> {
System.out.println("thread1线程启动了。。。");
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
});
thread1.start();
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
thread1.interrupt();
}
运行结果如下
1.线程启动是，默认中断标志位为false
2.如果main线程调用了thread1的interrupt()方法，中断标志位就变成了true
3.正常情况，中断标志位为true,如果thread1判断中断标志位为true就中断执行，则thread1停止，如果thread1线程自己不终止运行则不会停止。
4.异常情况，如果thread1线程正处于阻塞状态（例如处于sleep,wait,join等状态），将会把中断状态清除，并且将抛出InterruptedException异常，此时中断标志位还是false,thread1线程还会继续执行。
测试异常情况，并且循环不停止的情况，代码如下
public static void testInterrupt4(){
Thread thread1 = new Thread(() -> {
System.out.println("thread1线程启动了。。。");
try {
Thread.sleep(5000);
} catch (Exception e) {
e.printStackTrace();
}
while (true){
boolean interrupted = Thread.currentThread().isInterrupted();
if(interrupted){
System.out.println("thread1程序终止");
break;
}
}
});
thread1.start();
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
thread1.interrupt();
}
程序并没有停止
5.解决异常情况的方法，就是在catch块中，需要再次将中断标志位设置为true,2次调用才能使中断标志位改为true
public static void testInterrupt5(){
Thread thread1 = new Thread(() -> {
System.out.println("thread1线程启动了。。。");
try {
Thread.sleep(5000);
} catch (Exception e) {
// 抛出异常过后在此调用interrupt方法
Thread.currentThread().interrupt();
e.printStackTrace();
}
while (true){
boolean interrupted = Thread.currentThread().isInterrupted();
if(interrupted){
System.out.println("thread1程序终止");
break;
}
}
});
thread1.start();
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
thread1.interrupt();
}
判断线程是否被中断并清除当前中断状态
这个方法做了两件事情
1.返回当前线程的中断状态
2.将当前线程的中断状态清零并重新设置为false,清除线程的中断状态
public static void testInterrupt6(){
System.out.println(Thread.currentThread().getName() + "\t" + Thread.interrupted());
System.out.println(Thread.currentThread().getName() + "\t" + Thread.interrupted());
System.out.println("1111111111111111");
// 中断标志位设置为true
Thread.currentThread().interrupt();
System.out.println("2222222222222222");
System.out.println(Thread.currentThread().getName() + "\t" + Thread.interrupted());
System.out.println(Thread.currentThread().getName() + "\t" + Thread.interrupted());
}
该方法只会返回当前线程的中断标志位的状态;不会清除当前线程的中断标志位的状态
public static void testInterrupt7(){
System.out.println(Thread.currentThread().getName() + "\t" + Thread.currentThread().isInterrupted());
System.out.println(Thread.currentThread().getName() + "\t" + Thread.currentThread().isInterrupted());
System.out.println("1111111111111111");
// 中断标志位设置为true
Thread.currentThread().interrupt();
System.out.println("2222222222222222");
System.out.println(Thread.currentThread().getName() + "\t" + Thread.currentThread().isInterrupted());
System.out.println(Thread.currentThread().getName() + "\t" + Thread.currentThread().isInterrupted());
}
1.interrupted
public static boolean interrupted() {
return currentThread().isInterrupted(true);
}
2.isInterrupted
public boolean isInterrupted() {
return isInterrupted(false);
}
本质上都是调用了实例的isInterrupted方法，只是传入的参数有所不同，当传入true时，会情空当前线程的中断标志，重置为false,方传入false时，不会清空。
private native boolean isInterrupted(boolean ClearInterrupted);
该方法是被native修饰的方法
1.使用volatile 关键字来实现线程中断
static volatile boolean run = true;
public static void main(String[] args) {
new Thread(()->{
while (run){
System.out.println("线程1执行中...");
}
}).start();
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
run = false;
System.out.println("主线程结束");
}
2.使用同步代码块synchronized来实现线程中断
static boolean run = true;
static Object object = new Object();
public static void main(String[] args) {
new Thread(()->{
while (run){
System.out.println("线程1执行中...");
synchronized (object){
}
}
}).start();
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
run = false;
System.out.println("主线程结束");
}
3.使用AtomicBoolean 来实现线程中断
public static void main(String[] args) {
AtomicBoolean run = new AtomicBoolean(true);
new Thread(()->{
while (run.get()){
System.out.println("线程1执行中...");
}
}).start();
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
run.set(false);
System.out.println("主线程结束");
}
其运行结果如下