Corrupted string through Sockets in java

Question

I have the a problem transfering strings through sockets in Java. When i try to receive data from the server the data is transfered successfully but it's corrupted. I can't find out what is going wrong.

Here is the client piece of code:

public String getUserNameServerResult(String userNameParameter) {
    Socket socket;
    BufferedReader socketReader;
    PrintWriter socketWriter;
    String userNameResultParameter = null;
    try {
        socket = new Socket(HOST_NAME, PORT_NUMBER);
        socket.setSoTimeout(SERVER_REQUEST_TIMEOUT);
        socketReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        socketWriter = new PrintWriter(socket.getOutputStream());
        socketWriter.println(numberRequest);
        socketWriter.flush();
        socketWriter.println(userNameParameter);
        socketWriter.flush();
        userNameResultParameter = socketReader.readLine();
        socketReader.close();
        socketWriter.close();
        socket.close();
        System.out.println(userNameResultParameter);
    } catch(IOException ioEx) {
        ioEx.printStackTrace();
    }
        return userNameResultParameter;
}

The read line from readLine() method transfers a corrupted string.

Here is the server piece of code:

public synchronized void run(){
    System.out.println(new Date().toString()+" :\nAccepted client: "
            +socket.getInetAddress()+":"+socket.getPort()+"\n");
    try {
        while(!isInterrupted()) {
            String numberRequest = socketReader.readLine();
            if(numberRequest == null) {
                break;
            }
            switch(numberRequest) {
                case "1":    // Determines if the user name exists in the Database.
                    String userName = socketReader.readLine(); 
                    boolean isUserName = ServerRequest.isUserNameExists(userName);
                    socketWriter.println(isUserName);
                    socketWriter.flush();
                    break;
                default: break;
            }
        }
    } catch(IOException ex) {
        System.err.println(ex.getMessage());
    }
}

The "isUserName" variable is transfered and it gets corrupted in the client.

Can you help to solve this problem? Thanks!

Answer 1

isUserName is a boolean . Perhaps you meant socketWriter.println(userName); ?

Please use the code below to show us what the corrupted String looks like!

System.out.println(userNameResultParameter);
System.out.print("Chars:");
for (char c : userNameResultParameter.toCharArray())
    System.out.print(" 0x" + Integer.toHexString((int)c));

Answer 2

The problem, I think, is with the construction of the InputStreamReader . By default, the reader is assuming that the encoding of the incoming character data is your platform's default encoding, however the Writer (on the server side) is sending UTF-8 data.

Try constructing the InputStreamReader like this:

new InputStreamReader(socket.getInputStream(), "UTF-8")