Java多线程系列--“基础篇”09之 interrupt()和线程终止方式(四)
"t1"); // 新建“线程t1”
35 System.out.println(t1.getName() +" ("+t1.getState()+") is new.");
36
37 t1.start(); // 启动“线程t1”
38 System.out.println(t1.getName() +" ("+t1.getState()+") is started.");
39
40 // 主线程休眠300ms，然后主线程给t1发“中断”指令。
41 Thread.sleep(300);
42 t1.stopTask();
43 System.out.println(t1.getName() +" ("+t1.getState()+") is interrupted.");
44
45 // 主线程休眠300ms，然后查看t1的状态。
46 Thread.sleep(300);
47 System.out.println(t1.getName() +" ("+t1.getState()+") is interrupted now.");
48 } catch (InterruptedException e) {
49 e.printStackTrace();
50 }
51 }
52 }
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运行结果：
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t1 (NEW) is new.
t1 (RUNNABLE) is started.
t1 (RUNNABLE) loop 1
t1 (RUNNABLE) loop 2
t1 (TIMED_WAITING) is interrupted.
t1 (RUNNABLE) loop 3
t1 (TERMINATED) is interrupted now.
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4. interrupted() 和 isInterrupted()的区别
最后谈谈 interrupted() 和 isInterrupted()。
interrupted() 和 isInterrupted()都能够用于检测对象的“中断标记”。
区别是，interrupted()除了返回中断标记之外，它还会清除中断标记(即将中断标记设为false)；而isInterrupted()仅仅返回中断标记。
1. interrupt()说明
在介绍终止线程的方式之前，有必要先对interrupt()进行了解。
关于interrupt()，java的djk文档描述如下：http://docs.oracle.com/javase/7/docs/api/
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Interrupts this thread.
Unless the current thread is interrupting itself, which is always permitted, the checkAccess method of this thread is invoked, which may cause a SecurityException to be thrown.
If this thread is blocked in an invocation of the wait(), wait(long), or wait(long, int) methods of the Object class, or of the join(), join(long), join(long, int), sleep(long), or sleep(long, int), methods of this class, then its interrupt status will be cleared and it will receive an InterruptedException.
If this thread is blocked in an I/O operation upon an interruptible channel then the channel will be closed, the thread's interrupt status will be set, and the thread will receive a ClosedByInterruptException.
If this thread is blocked in a Selector then the thread's interrupt status will be set and it will return immediately from the selection operation, possibly with a non-zero value, just as if the selector's wakeup method were invoked.
If none of the previous conditions hold then this thread's interrupt status will be set.
Interrupting a thread that is not alive need not have any effect.
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大致意思是：
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interrupt()的作用是中断本线程。
本线程中断自己是被允许的；其它线程调用本线程的interrupt()方法时，会通过checkAccess()检查权限。这有可能抛出SecurityException异常。
如果本线程是处于阻塞状态：调用线程的wait(), wait(long)或wait(long, int)会让它进入等待(阻塞)状态，或者调用线程的join(), join(long), join(long, int), sleep(long), sleep(long, int)也会让它进入阻塞状态。若线程在阻塞状态时，调用了它的interrupt()方法，那么它的“中断状态”会被清除并且会收到一个InterruptedException异常。例如，线程通过wait()进入阻塞状态，此时通过interrupt()中断该线程；调用interrupt()会立即将线程的中断标记设为“true”，但是由于线程处于阻塞状态，所以该“中断标记”会立即被清除为“false”，同时，会产生一个InterruptedException的异常。
如果线程被阻塞在一个Selector选择器中，那么通过interrupt()中断它时；线程的中断标记会被设置为true，并且它会立即从选择操作中返回。
如果不属于前面所说的情况，那么通过interrupt()中断线程时，它的中断标记会被设置为“true”。
中断一个“已终止的线程”不会产生任何操作。
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2. 终止线程的方式
Thread中的stop()和suspend()方法，由于固有的不安全性，已经建议不再使用！
下面，我先分别讨论线程在“阻塞状态”和“运行状态”的终止方式，然后再总结出一个通用的方式。
2.1 终止处于“阻塞状态”的线程
通常，我们通过“中断”方式终