[ Java 常見問題 ] Is it possible to read from a InputStream with a timeout?

Source From Here 
Question 
Specifically, the problem is to write a method like this: 

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1. int maybeRead(InputStream in, long timeout)  

where the return value is the same as in.read() if data is available within 'timeout' milliseconds, and -2 otherwise. Before the method returns, any spawned threads must exit. 

How-To 
Assuming your stream is not backed by a socket (so you can't use Socket.setSoTimeout()), I think the standard way of solving this type of problem is to use aFuture. Suppose I have the following executor and streams: 

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1. ExecutorService executor = Executors.newFixedThreadPool(2);  
2. final PipedOutputStream outputStream = new PipedOutputStream();  
3. final PipedInputStream inputStream = new PipedInputStream(outputStream);  

I have writer that writes some data then waits for 5 seconds before writing the last piece of data and closing the stream: 

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1. Runnable writeTask = new Runnable() {  
2.     @Override  
3.     public void run() {  
4.         try {  
5.             outputStream.write(1);  
6.             outputStream.write(2);  
7.             Thread.sleep(5000);  
8.             outputStream.write(3);  
9.             outputStream.close();  
10.         } catch (Exception e) {  
11.             e.printStackTrace();  
12.         }  
13.     }  
14. };  
15. executor.submit(writeTask);  

The normal way of reading this is as follows. The read will block indefinitely for data and so this completes in 5s: 

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1. long start = System.currentTimeMillis();  
2. int readByte = 1;  
3. // Read data without timeout  
4. while (readByte >= 0) {  
5.     readByte = inputStream.read();  
6.     if (readByte >= 0)  
7.         System.out.println("Read: " + readByte);  
8. }  
9. System.out.println("Complete in " + (System.currentTimeMillis() - start) + "ms");  
10. executor.shutdown()  

which outputs: 

Read: 1
Read: 2
Read: 3
Complete in 5001ms

If there was a more fundamental problem, like the writer not responding, the reader would block for ever. If I wrap the read in a future, I can then control the timeout as follows: 

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1. int readByte = 1;  
2. // Read data with timeout  
3. Callable readTask = new Callable() {  
4.     @Override  
5.     public Integer call() throws Exception   
6.     {  
7.         return inputStream.read();  
8.     }  
9. };  
10. try  
11. {  
12.     while (readByte >= 0)   
13.     {  
14.         Future future = executor.submit(readTask);  
15.         readByte = future.get(1000, TimeUnit.MILLISECONDS);  
16.         if (readByte >= 0) System.out.println("Read: " + readByte);  
17.     }  
18. }  
19. catch(Exception e){System.err.printf("\t[Error] %s\n", e)}  

which outputs: 

Read: 1
Read: 2
[Error] java.util.concurrent.TimeoutException

Supplement 
* Java concurrency (multi-threading) - Tutorial