while(!Thread.currentThread().isInterrupted() && more work to do){ do more work }
public void run() { try { ... /* * 不管循环里是否调用过线程阻塞的方法如sleep、join、wait,这里还是需要加上 * !Thread.currentThread().isInterrupted()条件,虽然抛出异常后退出了循环,显 * 得用阻塞的情况下是多余的,但如果调用了阻塞方法但没有阻塞时,这样会更安全、更及时。 */ while (!Thread.currentThread().isInterrupted()&& more work to do) { do more work } } catch (InterruptedException e) { //线程在wait或sleep期间被中断了 } finally { //线程结束前做一些清理工作 } }
public void run() { while (!Thread.currentThread().isInterrupted()&& more work to do) { try { ... sleep(delay); } catch (InterruptedException e) { Thread.currentThread().interrupt();//重新设置中断标示 } } }
void mySubTask(){ ... try{ sleep(delay); }catch(InterruptedException e){}//不要这样做 ... }
void mySubTask() { ... try { sleep(delay); } catch (InterruptedException e) { Thread.currentThread().isInterrupted(); } ... }
void mySubTask() throws InterruptedException { ... sleep(delay); ... }
class Example2 extends Thread { volatile boolean stop = false;// 线程中断信号量 public static void main(String args[]) throws Exception { Example2 thread = new Example2(); System.out.println("Starting thread..."); thread.start(); Thread.sleep(3000); System.out.println("Asking thread to stop..."); // 设置中断信号量 thread.stop = true; Thread.sleep(3000); System.out.println("Stopping application..."); } public void run() { // 每隔一秒检测一下中断信号量 while (!stop) { System.out.println("Thread is running..."); long time = System.currentTimeMillis(); /* * 使用while循环模拟 sleep 方法,这里不要使用sleep,否则在阻塞时会 抛 * InterruptedException异常而退出循环,这样while检测stop条件就不会执行, * 失去了意义。 */ while ((System.currentTimeMillis() - time < 1000)) {} } System.out.println("Thread exiting under request..."); } }
class Example2 extends Thread { public static void main(String args[]) throws Exception { Example2 thread = new Example2(); System.out.println("Starting thread..."); thread.start(); Thread.sleep(3000); System.out.println("Asking thread to stop..."); // 发出中断请求 thread.interrupt(); Thread.sleep(3000); System.out.println("Stopping application..."); } public void run() { // 每隔一秒检测是否设置了中断标示 while (!Thread.currentThread().isInterrupted()) { System.out.println("Thread is running..."); long time = System.currentTimeMillis(); // 使用while循环模拟 sleep while ((System.currentTimeMillis() - time < 1000) ) { } } System.out.println("Thread exiting under request..."); } }
class Example3 extends Thread { public static void main(String args[]) throws Exception { Example3 thread = new Example3(); System.out.println("Starting thread..."); thread.start(); Thread.sleep(3000); System.out.println("Asking thread to stop..."); thread.interrupt();// 等中断信号量设置后再调用 Thread.sleep(3000); System.out.println("Stopping application..."); } public void run() { while (!Thread.currentThread().isInterrupted()) { System.out.println("Thread running..."); try { /* * 如果线程阻塞,将不会去检查中断信号量stop变量,所 以thread.interrupt() * 会使阻塞线程从阻塞的地方抛出异常,让阻塞线程从阻塞状态逃离出来,并 * 进行异常块进行 相应的处理 */ Thread.sleep(1000);// 线程阻塞,如果线程收到中断操作信号将抛出异常 } catch (InterruptedException e) { System.out.println("Thread interrupted..."); /* * 如果线程在调用 Object.wait()方法,或者该类的 join() 、sleep()方法 * 过程中受阻,则其中断状态将被清除 */ System.out.println(this.isInterrupted());// false //中不中断由自己决定,如果需要真真中断线程,则需要重新设置中断位,如果 //不需要,则不用调用 Thread.currentThread().interrupt(); } } System.out.println("Thread exiting under request..."); } }
class Example4 extends Thread { public static void main(String args[]) throws Exception { final Object lock1 = new Object(); final Object lock2 = new Object(); Thread thread1 = new Thread() { public void run() { deathLock(lock1, lock2); } }; Thread thread2 = new Thread() { public void run() { // 注意,这里在交换了一下位置 deathLock(lock2, lock1); } }; System.out.println("Starting thread..."); thread1.start(); thread2.start(); Thread.sleep(3000); System.out.println("Interrupting thread..."); thread1.interrupt(); thread2.interrupt(); Thread.sleep(3000); System.out.println("Stopping application..."); } static void deathLock(Object lock1, Object lock2) { try { synchronized (lock1) { Thread.sleep(10);// 不会在这里死掉 synchronized (lock2) {// 会锁在这里,虽然阻塞了,但不会抛异常 System.out.println(Thread.currentThread()); } } } catch (InterruptedException e) { e.printStackTrace(); System.exit(1); } } }
class Example6 extends Thread { volatile ServerSocket socket; public static void main(String args[]) throws Exception { Example6 thread = new Example6(); System.out.println("Starting thread..."); thread.start(); Thread.sleep(3000); System.out.println("Asking thread to stop..."); Thread.currentThread().interrupt();// 再调用interrupt方法 thread.socket.close();// 再调用close方法 try { Thread.sleep(3000); } catch (InterruptedException e) { } System.out.println("Stopping application..."); } public void run() { try { socket = new ServerSocket(8888); } catch (IOException e) { System.out.println("Could not create the socket..."); return; } while (!Thread.currentThread().isInterrupted()) { System.out.println("Waiting for connection..."); try { socket.accept(); } catch (IOException e) { System.out.println("accept() failed or interrupted..."); Thread.currentThread().interrupt();//重新设置中断标示位 } } System.out.println("Thread exiting under request..."); } }
#include "jni.h" #include "jvm.h" #include "java_lang_Thread.h" #define THD "Ljava/lang/Thread;" #define OBJ "Ljava/lang/Object;" #define STE "Ljava/lang/StackTraceElement;" #define ARRAY_LENGTH(a) (sizeof(a)/sizeof(a[0])) static JNINativeMethod methods[] = { {"start0", "()V", (void *)&JVM_StartThread}, {"stop0", "(" OBJ ")V", (void *)&JVM_StopThread}, {"isAlive", "()Z", (void *)&JVM_IsThreadAlive}, {"suspend0", "()V", (void *)&JVM_SuspendThread}, {"resume0", "()V", (void *)&JVM_ResumeThread}, {"setPriority0", "(I)V", (void *)&JVM_SetThreadPriority}, {"yield", "()V", (void *)&JVM_Yield}, {"sleep", "(J)V", (void *)&JVM_Sleep}, {"currentThread", "()" THD, (void *)&JVM_CurrentThread}, {"countStackFrames", "()I", (void *)&JVM_CountStackFrames}, {"interrupt0", "()V", (void *)&JVM_Interrupt}, {"isInterrupted", "(Z)Z", (void *)&JVM_IsInterrupted}, {"holdsLock", "(" OBJ ")Z", (void *)&JVM_HoldsLock}, {"getThreads", "()[" THD, (void *)&JVM_GetAllThreads}, {"dumpThreads", "([" THD ")[[" STE, (void *)&JVM_DumpThreads}, }; #undef THD #undef OBJ #undef STE JNIEXPORT void JNICALL Java_java_lang_Thread_registerNatives(JNIEnv *env, jclass cls) { (*env)->RegisterNatives(env, cls, methods, ARRAY_LENGTH(methods)); }