简体   繁体   中英

Client reading too many bytes from server?

I'm writing a simple FTP client/server setup. The client is supposed to be able to retrieve a file from the server and place the result as a stream of bytes into /retr_files/filex. The appropriate responses are sent from the server, and file1 is indeed created in the folder. However, too many bytes were sent (or received). I tested this on a 9.6kB file and the file it made client-side was 16.6kB. Odd. I feel like I'm missing something obvious here, can someone help me out? Thanks!

Relevant code:

Client:

BufferedReader inFromServer_d = null;

    if(welcomeSocket!=null){
        if(!welcomeSocket.isClosed()){
            welcomeSocket.close();
        }
    }

    try {
        welcomeSocket = new ServerSocket(port);
        System.out.print("PORT " + myIP + "," + num1 + "," + num2 + "\r\n");
        out.writeBytes("PORT " + myIP + "," + num1 + "," + num2 + "\r\n");
        System.out.print(parseReply(getResponse()));
        System.out.print("RETR " + pathname + "\r\n");
        out.writeBytes("RETR " + pathname + "\r\n");
        String reply = parseReply(getResponse());
        if (reply.charAt(10)=='1') {
            System.out.print(reply);
            System.out.print(parseReply(getResponse()));

            try{
                clientSocket_d = welcomeSocket.accept();
            } catch (IOException e) {
                System.out.print("GET failed, FTP-data port not allocated.\r\n");
                System.exit(-1);
            }


                inFromServer_d = new BufferedReader(new InputStreamReader(
                        clientSocket_d.getInputStream()));


            // READ
            BufferedReader bufferedReader = inFromServer_d;
            FileWriter output = new FileWriter("retr_files/file" + retrCnt);
            BufferedWriter bufferedWriter = new BufferedWriter(output);

            String length;
            while ((length = bufferedReader.readLine()) != null) {
                bufferedWriter.write(length + "\n");
            }

            bufferedReader.close();
            bufferedWriter.close();
            clientSocket_d.close();

Server:

//TCP CONNECT
                        DataOutputStream outToClient_d = null;
                        Socket clientSocket1 = null;


                        try {
                            ipAddress = ipAddress.substring(0, ipAddress.length()-1);
                        clientSocket1 = new Socket(ipAddress, portNumber);
                        outToClient_d = new DataOutputStream(clientSocket1.getOutputStream());
                        }

                        catch(UnknownHostException e){
                          out.writeBytes("425 Can not open data connection.\r\n");
                        }



                        BufferedReader bufferedReader = new BufferedReader(input);

                        String length;
                        while((length = bufferedReader.readLine())!=null){
                            outToClient_d.writeBytes(length+"\n");
                        }
                        out.writeBytes("250 Requested file action completed.\r\n");
                        bufferedReader.close();
                        clientSocket1.close();
                        outToClient_d.close();

}

Don't use Readers and Writers and readLine(). All files are not text files, and not all text files have line breaks. Use streams.

I guess at your client side , the newly created file must have extra new line between each printed lines. That might lead to increase in size of file. AT client side replace this line :

bufferedWriter.write(length + "\n");

To

bufferedWriter.write(length);

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM