发送整数值，然后将整个文件从客户端发送到Java中的服务器

Question

Basically, this is what I have done:- Client side

public class Client {

    public String uploadFile(String filePath,int language) throws Exception {
        Socket sock = new Socket("127.0.0.1", 25000);


        // make the file object from filepath
        File myFile = new File(filePath);

        // send the integer 'language'
        OutputStream os = sock.getOutputStream();
        OutputStreamWriter osw = new OutputStreamWriter(os);
        BufferedWriter bw = new BufferedWriter(osw);
        bw.write(language);
        bw.flush();

        // send the file data
        byte[] mybytearray = new byte[(int) myFile.length()];
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(
                myFile));
        bis.read(mybytearray, 0, mybytearray.length);
        os.write(mybytearray, 0, mybytearray.length);
        os.flush();
        bis.close();

        // get the reply
        InputStream is = sock.getInputStream();
        InputStreamReader isr = new InputStreamReader(is);
        BufferedReader br = new BufferedReader(isr);
        String message = br.readLine();

        sock.close();

        return message;

    }
}

Server side:-

 void connectToNewClient(Socket sock) throws IOException,
            InterruptedException {

        // get the integer 'language'

        InputStream is = sock.getInputStream();
        InputStreamReader isr = new InputStreamReader(is);
        BufferedReader br = new BufferedReader(isr);
        String language = br.readLine();

        // Read file data sent by client and store in server
        byte[] mybytearray = new byte[50000];
        FileOutputStream fos = new FileOutputStream("Main.txt");
        BufferedOutputStream bos = new BufferedOutputStream(fos);
        int bytesRead = is.read(mybytearray, 0, mybytearray.length);
        bos.write(mybytearray, 0, bytesRead);
        bos.close();

        // give back response
        OutputStream os = sock.getOutputStream();
        OutputStreamWriter osw = new OutputStreamWriter(os);
        BufferedWriter bw = new BufferedWriter(osw);
        bw.write(response);

        bw.flush();

        sock.close();

    }

So my problem is that when I send only the file or only the integer from client, I can receive them at server side, but, when I try sending them both together I do not receive anything at server side. Guess I have messed up with so many writer objects and data stream objects. Please help with where I have gone wrong. Thank you. NOTE: I have removed a few lines of code in between which I thought were not relevant to my problem.

Answer 1

You're wrapping your stream inside a BufferedWriter which is usually a good thing for a number of reasons. The weird thing with your code is that you're using that writer for the Integer, and the unwrapped OutputStream for the File. I suspect that the two write operations cannot be used without reinstantiating the writer.

I suggest you to refactor your code using only one writer. I would choose the more general ObjectOutputStream which allows you to send objects implementing the Serializable interface (your scenario already satisfy this constraint). You can receive directly the objects via ObjectInputStream.