Java sending and receiving file (byte[]) over sockets

Question

I am trying to develop a very simple client / server where the client converts a file to bytes, sends it to the server, and then converts the bytes back in to a file.

Currently the program just creates an empty file. I'm not a fantastic Java developer so any help much appreciated.

This is the server part that receives what the client sends.

ServerSocket serverSocket = null;      serverSocket = new ServerSocket(4444);       Socket socket = null;     socket = serverSocket.accept();      DataOutputStream out = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));     DataInputStream in = new DataInputStream(new BufferedInputStream(socket.getInputStream()));     byte[] bytes = new byte[1024];      in.read(bytes);     System.out.println(bytes);      FileOutputStream fos = new FileOutputStream("C:\\test2.xml");     fos.write(bytes); 

And here is the client part

Socket socket = null;     DataOutputStream out = null;     DataInputStream in = null;     String host = "127.0.0.1";           socket = new Socket(host, 4444);     out = new DataOutputStream(new BufferedOutputStream(socket.getOutputStream()));     in = new DataInputStream(new BufferedInputStream(socket.getInputStream()));      File file = new File("C:\\test.xml");     //InputStream is = new FileInputStream(file);     // Get the size of the file     long length = file.length();     if (length > Integer.MAX_VALUE) {         System.out.println("File is too large.");     }     byte[] bytes = new byte[(int) length];      //out.write(bytes);     System.out.println(bytes);      out.close();     in.close();     socket.close(); 

Answer 1

The correct way to copy a stream in Java is as follows:

int count; byte[] buffer = new byte[8192]; // or 4096, or more while ((count = in.read(buffer)) > 0) {   out.write(buffer, 0, count); } 

Wish I had a dollar for every time I've posted that in a forum.