Java套接字超时：管道损坏

Question

I'm writing a simple server in Java, and I'm able to retrieve incoming data from the client on the server side, but not on the client side due to a 2000ms timeout. Anyone know why this times out?

This is the server's code:

private static void listen() throws IOException {
    while(true) {
        Socket clientSocket = serverSocket.accept();
        StringBuilder bufferedStringInput = new StringBuilder(); 
        CharBuffer cbuf = CharBuffer.allocate(4096);
        try {
            InputStream is = clientSocket.getInputStream();
            BufferedReader br = new BufferedReader(new InputStreamReader(is, "UTF8"));
            int noCharsLeft = 0;
            while ((noCharsLeft = br.read(cbuf)) != -1) { 
                char[] arr = new char[noCharsLeft];
                cbuf.rewind();
                cbuf.get(arr);
                bufferedStringInput.append(arr);
                cbuf.clear();
            }           
            System.out.println(bufferedStringInput.toString());
        } catch (IOException e) {
            System.out.println("Error received client data: " + e.getMessage());
        }

        String message = "Hello client";
        try {
            PrintWriter out = new PrintWriter(clientSocket.getOutputStream());
            out.print(message);
        } catch (IOException e) {
            System.out.println("Error getting output stream from client: " + e.getMessage());
        }
        clientSocket.close();       
    } 
}

Answer 1

You're reading the input until end of stream, which only happens when the peer closes the connection, then you're trying to write to it, so of course you get a broken pipe. Doesn't make sense. You should just read the input until you have one entire request, whatever that means in your protocol.

There are other problems lurking here:

• If the client code uses readLine() , you're not sending a line terminator: use println(), not print(), and close the PrintWriter , not just the client socket.

• cbuf.rewind()/get()/clear() should be cbuf.flip()/get()/compact().

• But it would make more sense to read directly into a char[] cbuf = new char[8192]; array, then bufferedStringInput.append(cbuf, 0, noCharsLeft), and forget about the CharBuffer altogether. Too much data copying at present.

• noCharsLeft is a poor name for that variable. It is a read count.