这个程序想说明，因同步 IO 资源而阻塞的线程，可以通过关闭 IO 资源而停止阻塞。

//: concurrency/CloseResource.java // Interrupting a blocked task by // closing the underlying resource. // {RunByHand} import java.net.*; import java.util.concurrent.*; import java.io.*; import static net.mindview.util.Print.*;  class IOBlocked implements Runnable {     private InputStream in;     public IOBlocked(InputStream is) { in = is; }     public void run() {         try {             print("Waiting for read():");             in.read();         } catch(Exception e) {             e.printStackTrace();  //这句是我加的             if(Thread.currentThread().isInterrupted()) {                 print("Interrupted from blocked I/O");             } else {                 throw new RuntimeException(e);             }         }         print("Exiting IOBlocked.run()");     } }  public class CloseResource {     public static void main(String[] args) throws Exception {         ExecutorService exec = Executors.newCachedThreadPool();         ServerSocket server = new ServerSocket(8080);         InputStream socketInput =                 new Socket("localhost", 8080).getInputStream();         exec.execute(new IOBlocked(socketInput));         exec.execute(new IOBlocked(System.in));         TimeUnit.MILLISECONDS.sleep(100);         print("Shutting down all threads");         exec.shutdownNow();         TimeUnit.SECONDS.sleep(1);         print("Closing " + socketInput.getClass().getName());         socketInput.close(); // Releases blocked thread         TimeUnit.SECONDS.sleep(1);         print("Closing " + System.in.getClass().getName());         System.in.close(); // Releases blocked thread     } }/* Output: (85% match) Waiting for read(): Waiting for read(): Shutting down all threads Closing java.net.SocketInputStream Interrupted from blocked I/O Exiting IOBlocked.run() Closing java.io.BufferedInputStream Exiting IOBlocked.run()            //书中的打印结果就有这句，而我的没有 *///:~ 

打印结果：

Waiting for read(): Waiting for read(): Shutting down all threads Closing java.net.SocketInputStream java.net.SocketException: Socket closed  at java.net.SocketInputStream.socketRead0(Native Method)  at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)  at java.net.SocketInputStream.read(SocketInputStream.java:170)  at java.net.SocketInputStream.read(SocketInputStream.java:141)  at java.net.SocketInputStream.read(SocketInputStream.java:223)  at IOBlocked.run(Interrupting.java:24)  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)  at java.lang.Thread.run(Thread.java:745) Interrupted from blocked I/O Exiting IOBlocked.run() Closing java.io.BufferedInputStream 

执行后，程序无法结束，从打印结果也可以看出，第二个线程还是处于运行中。这个例子来自 java 编程思想，书中说到，两个线程都会因为资源的关闭而结束.

所以，为什么因为 System.in.read()而阻塞的线程，无法通过 System.in.close()唤醒（可能是以抛出异常的方式）？明明书中都说可以，难道是 java 版本问题