关于InterruptedException

1.InterruptedException的由来

"Thread.sleep(long millis)", 以及"thread.wait()"方法，都会抛出InterruptedException，很多时候都不知道怎么处理这个异常；这个异常是由thread.interrupt()产生的，比如如果A线程在wait状态，此时B线程调用aThread.interrupt()方法，那么A线程就会从阻塞状态恢复，并抛出InterruptedException；大部分时候我们我不使用interrupt()方法，所以我们可以直接在抛出InterruptedException的地方捕获住，然后Thread.currentThread().interrupt(), 将interrupted status 置为true就可以了，当然至于interrupted status的状态有什么作用，要这么处理，这是上层代码改决定的事。

2.interrupt()注释

    /**
     * 中断当前线程；
     *
     * 如果这个线程被wait(), join(), sleep()所阻塞，
     * 那么线程的中断状态将被清除，同时，会抛出一个InterruptedException；
     *
     * <p> If this thread is blocked in an invocation of the {@link
     * Object#wait() wait()}, {@link Object#wait(long) wait(long)}, or {@link
     * Object#wait(long, int) wait(long, int)} methods of the {@link Object}
     * class, or of the {@link #join()}, {@link #join(long)}, {@link
     * #join(long, int)}, {@link #sleep(long)}, or {@link #sleep(long, int)},
     * methods of this class, then its interrupt status will be cleared and it
     * will receive an {@link InterruptedException}.
     * 
     * 如果这个线程是被I/O(基于InterruptibleChannel)操作所阻塞，
     * 那么这个I/O通道教会被关闭，
     * 线程interrupt状态会被设置为true，
     * 同时会抛出一个ClosedByInterruptException；
     * 
     * <p> If this thread is blocked in an I/O operation upon an {@link
     * java.nio.channels.InterruptibleChannel InterruptibleChannel}
     * then the channel will be closed, the thread's interrupt
     * status will be set, and the thread will receive a {@link
     * java.nio.channels.ClosedByInterruptException}.
     *
     * 如果这个线程是被link java.nio.channels.Selector所阻塞，
     * 那么这个线程的interrupt状态会被设置为true，
     * 并且会直接从selection操作中return，
     * 就好像select.wakeup()一样；
     *
     * <p> If this thread is blocked in a {@link java.nio.channels.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 {@link
     * java.nio.channels.Selector#wakeup wakeup} method were invoked.
     *
     * 如果不存在前面所有情况，那么这个线程的interrupt状态将会被设置为true;
     *
     * <p> If none of the previous conditions hold then this thread's interrupt
     * status will be set. </p>
     *
     * <p> Interrupting a thread that is not alive need not have any effect.
     *
     * @throws  SecurityException
     *          if the current thread cannot modify this thread
     *
     * @revised 6.0
     * @spec JSR-51
     */
    //Thread.java
    public void interrupt() {

        if (this != Thread.currentThread())
            checkAccess();

        synchronized (blockerLock) {
            Interruptible b = blocker;
            if (b != null) {
                interrupt0();           // Just to set the interrupt flag
                b.interrupt(this);
                return;
            }
        }
        interrupt0();
    }