使用dataInputStream和dataOutputStream造成“死锁”或“阻塞”

如题，请各位大侠帮我看看，如何解决//客户端
public class ClientTest_Short {
    private ClientSocket_Short cs = null;

    private String ip = "localhost";// 设置成服务器IP

    private int port = 8821;

    private String sendMessage = "sss";

    private Socket socket = null;

    public ClientTest_Short() {
        try {
            if (createConnection()) {
                sendMessage();
//                getMessage();
            }

        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    private boolean createConnection() {
        cs = new ClientSocket_Short(ip, port);
        try {
            socket = cs.CreateConnection();
            if(socket != null)
            {
             System.out.print("连接服务器成功!" + "\n");
            }
            else
            {
             System.out.println("socket is null");
            }
            return true;
        } catch (Exception e) {
            System.out.print("连接服务器失败!" + "\n");
            return false;
        }

    }

    private void sendMessage() throws IOException {
        String filePath = "D:\\OOo_3.2.0rc5_20100203_Win32Intel_install_wJRE_zh-CN.exe";
        File fi = new File(filePath);           System.out.println("文件长度:" + (int) fi.length());
        System.out.println("建立socket链接");        DataInputStream fis = new DataInputStream(new BufferedInputStream(new FileInputStream(filePath)));
        DataOutputStream ps = new DataOutputStream(socket.getOutputStream());
        //将文件名及长度传给客户端。这里要真正适用所有平台，例如中文名的处理，还需要加工，具体可以参见Think In Java 4th里有现成的代码。
        ps.writeUTF(fi.getName());
        ps.flush();
        ps.writeLong((long) fi.length());
        ps.flush();           int bufferSize = 8192;
        byte[] buf = new byte[bufferSize];           while (true) {
            int read = 0;
            if (fis != null) {
                read = fis.read(buf);
            }               if (read == -1) {
                break;
            }
            ps.write(buf, 0, read);
        }
        ps.flush();
        fis.close();

        //接收服务器端成功返回信息
        DataInputStream inputStream = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
        //在这里发生死锁或者阻塞
        System.out.println("从服务器返回的信息 = " + inputStream.readUTF());

        socket.close();
        System.out.println("文件传输完成");
    }
    public static void main(String arg[]) {
        new ClientTest_Short();
    }
}  //服务器端
public class ServerTest_Short {
    int port = 8821;

    void start() {
        Socket s = null;
        try {
            ServerSocket ss = new ServerSocket(port);
            while (true) {
                // 选择进行传输的文件
                String filePath = "D:/compress-image.sh";
                File fi = new File(filePath);

                System.out.println("文件长度:" + (int) fi.length());

                // public Socket accept() throws
                // IOException侦听并接受到此套接字的连接。此方法在进行连接之前一直阻塞。

                s = ss.accept();
                DataInputStream inputStream = null;
                try {
                    inputStream = new DataInputStream(new BufferedInputStream(s.getInputStream()));
                } catch (Exception e) {
                    System.out.print("接收消息缓存错误\n");
                    return;
                }

                try {
                    //本地保存路径，文件名会自动从服务器端继承而来。
                    String savePath = "E:\\";
                    int bufferSize = 8192;
                    byte[] buf = new byte[bufferSize];
                    int passedlen = 0;
                    long len=0;

                    savePath += inputStream.readUTF();
                    System.out.println("savePath = " + savePath);
                    DataOutputStream fileOut = new DataOutputStream(new BufferedOutputStream(new BufferedOutputStream(new FileOutputStream(savePath))));
                    len = inputStream.readLong();

                    System.out.println("文件的长度为:" + len + "\n");
                    System.out.println("开始接收文件!" + "\n");

                    while (true) {
                        int read = 0;
                        if (inputStream != null) {
                            read = inputStream.read(buf);
                        }
                        passedlen += read;
                        if (read == -1) {
                            break;
                        }
                        //下面进度条本为图形界面的prograssBar做的，这里如果是打文件，可能会重复打印出一些相同的百分比
//                        System.out.println("文件接收了" +  (passedlen * 100/ len) + "%\n");
                        fileOut.write(buf, 0, read);
                    }
                    System.out.println("接收完成，文件存为" + savePath + "\n");
                    fileOut.close();

                    //将成功信息返回客户端
                    DataOutputStream outputStream = new DataOutputStream(s.getOutputStream());
                    outputStream.writeUTF("success");
                    outputStream.flush();

                } catch (Exception e) {
                    System.out.println("接收消息错误" + "\n");
                    return;
                }                     }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String arg[]) {
        new ServerTest_Short().start();
    }
}//工具类
public class ClientSocket_Short {
    private String ip;

    private int port;

    private Socket socket = null;

    DataOutputStream out = null;

    DataInputStream getMessageStream = null;

    public ClientSocket_Short(String ip, int port) {
        this.ip = ip;
        this.port = port;
    }

    /** *//**
     * 创建socket连接
     *
     * @throws Exception
     *             exception
     */
    public Socket CreateConnection() throws Exception {
        try {
            socket = new Socket(ip, port);
        } catch (Exception e) {
            e.printStackTrace();
            if (socket != null)
                socket.close();
            throw e;
        } finally {
        }
        return socket;
    }

    public void sendMessage(String sendMessage) throws Exception {
        try {
            out = new DataOutputStream(socket.getOutputStream());
            if (sendMessage.equals("Windows")) {
                out.writeByte(0x1);
                out.flush();
                return;
            }
            if (sendMessage.equals("Unix")) {
                out.writeByte(0x2);
                out.flush();
                return;
            }
            if (sendMessage.equals("Linux")) {
                out.writeByte(0x3);
                out.flush();
            } else {
                out.writeUTF(sendMessage);
                out.flush();
            }
        } catch (Exception e) {
            e.printStackTrace();
            if (out != null)
                out.close();
            throw e;
        } finally {
        }
        System.out.println("发送结束1");
    }

    public DataInputStream getMessageStream() throws Exception {
        try {
            getMessageStream = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
            return getMessageStream;
        } catch (Exception e) {
            e.printStackTrace();
            if (getMessageStream != null)
                getMessageStream.close();
            throw e;
        } finally {
        }
    }

    public void shutDownConnection() {
        try {
            if (out != null)
                out.close();
            if (getMessageStream != null)
                getMessageStream.close();
            if (socket != null)
                socket.close();
        } catch (Exception e) {

        }
    }
}

解决方案 »

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刚测试了一下LZ的代码，问题出在服务端。
把服务端读取客户端信息那处的“if (read == -1)”改为“if (read <= buf.length)”即可。
因为LZ程序中服务端的“if (read == -1)”在客户端输出口不close的情况下，永远不会成立，所以会锁死。没想到翻了个老帖出来，希望对新手有所帮助。我自己也是菜鸟，有什么说错的请多多指教。
忘了说“fileOut.write(buf, 0, read);”需要放到“if (read <= buf.length)”上面测试小文件没问题，大文件同样出现阻塞现象（估计是客户端问题）……等高人解答