Java 中断线程
如果任何线程处于睡眠或等待状态(即调用sleep()或wait()),则在该线程上调用interrupt()方法将抛出睡眠状态或等待状态,并抛出InterruptedException。如果线程未处于睡眠或等待状态,则调用interrupt()方法将执行正常行为,并且不会中断线程,而是将中断标志设置为true。首先,让我们看看Thread类提供的用于中断线程的方法。
Thread类提供的3种中断线程的方法
public void interrupt()
public static boolean interrupted()
public boolean isInterrupted()
中断正在停止工作的线程的示例
在此示例中,在中断线程之后,我们正在传播该线程,因此它将停止工作。如果我们不想停止线程,则可以在调用sleep()或wait()方法的地方进行处理。首先让我们看一下传播异常的示例。
class TestInterruptingThread1 extends Thread{
public void run(){
try{
Thread.sleep(1000);
System.out.println("task");
}
catch(InterruptedException e){
throw new RuntimeException("Thread interrupted..."+e);
}
}
public static void main(String args[]){
TestInterruptingThread1 t1=new TestInterruptingThread1();
t1.start();
try{
t1.interrupt();
}
catch(Exception e){
System.out.println("Exception handled "+e);
}
}
}
Output:Exception in thread-0 java.lang.RuntimeException: Thread interrupted... java.lang.InterruptedException: sleep interrupted at A.run(A.java:7)
中断无法停止工作的线程的示例
在此示例中,在中断线程之后,我们将处理异常,因此它将打破休眠状态,但不会停止工作。
class TestInterruptingThread2 extends Thread{
public void run(){
try{
Thread.sleep(1000);
System.out.println("task");
}
catch(InterruptedException e){
System.out.println("Exception handled "+e);
}
System.out.println("thread is running...");
}
public static void main(String args[]){
TestInterruptingThread2 t1=new TestInterruptingThread2();
t1.start();
t1.interrupt();
}
}
Output:Exception handled java.lang.InterruptedException: sleep interrupted thread is running...
中断正常运行的线程的示例
如果线程未处于睡眠或等待状态,则调用interrupt()方法会将interrupted标志设置为true,该标志可稍后由Java程序员用来停止线程。
class TestInterruptingThread3 extends Thread{
public void run(){
for(int i=1;i<=5;i++)System.out.println(i);
}
public static void main(String args[]){
TestInterruptingThread3 t1=new TestInterruptingThread3();
t1.start();
t1.interrupt();
}
}
isInterrupted和interrupted方法怎么样?
isInterrupted()方法返回中断标志true或false。静态interrupted()方法返回中断标志,然后将其设置为false(如果为true)。
public class TestInterruptingThread4 extends Thread{
public void run(){
for(int i=1;i<=2;i++){
if(Thread.interrupted()){
System.out.println("code for interrupted thread");
}
else{
System.out.println("code for normal thread");
}
}
//end of for loop}
public static void main(String args[]){
TestInterruptingThread4 t1=new TestInterruptingThread4();
TestInterruptingThread4 t2=new TestInterruptingThread4();
t1.start();
t1.interrupt();
t2.start();
}
}
Output:Code for interrupted thread code for normal thread code for normal thread code for normal thread