Java套接字UDP循环

Question

I am trying to set up a program that looks into UDP performance of packets and response times on my network. I have a client and server side class, for which I am specifying the packet size which to send pieces of text. For example, if I want to send a word of "Tester" in a 4 byte packet, it will send the "TEST" part but not reiterate through the rest of the word. I have tried to add in a while loop, but i don't think what I have is correct as it continuously sends the first 4 bytes. Does anyone know what sort of loop I need and where abouts it should be placed to get the outcome I am after? Code for the client is below. Many thanks in advance for any guidance.

//UDP Client
//Usage: java UDPClient [server addr] [server port]

import java.io.*;
import java.net.*;

public class UDPClient extends variable {

   // static Integer portNo = 4444;
    static Integer byteSize = 4;

    public static void main(String[] args) throws Exception {
      SocketForm form = new SocketForm();

      long startTime; // Starting time of program, in milliseconds.
      long endTime;   // Time when computations are done, in milliseconds.
      double time;  

        //get server address
        String serverName = "localhost";

        if (args.length >= 1)
            serverName = args[0];
      InetAddress serverIPAddress = InetAddress.getByName(serverName);

        //get server port;
        int serverPort = form.cliportNo;
        if (args.length >= 2)
            serverPort = Integer.parseInt(args[1]);
        //create socket
        DatagramSocket clientSocket = new DatagramSocket();
        //get input from keybaord
        byte[] sendData = new byte[byteSize];
        BufferedReader inFromUser = new BufferedReader(new InputStreamReader (System.in));
        while (true){ //incorrect as it is only repeating the first four bytes of the word typed in the console
        String sentence = inFromUser.readLine();
        startTime = System.currentTimeMillis();
        sendData = sentence.getBytes();
        //construct and send datagram;

        DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, serverIPAddress, serverPort);
        clientSocket.send(sendPacket);

        //receive datagram
        byte[] receiveData = new byte [byteSize];

        DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
        clientSocket.receive(receivePacket);
        //print output
        String sentenceFromServer = new String(receivePacket.getData());
        System.out.println("From Server:" + sentenceFromServer);

        //close client socket
                //clientSocket.close();
        endTime = System.currentTimeMillis();
        time = endTime - startTime;
        //System.out.println("Time :" + time);
        }
    } //end of main
} //end of UDPClient

Answer 1

Do you mean like this?

private void sendChunked( String msg, int chunkSizeInBytes ) {
   byte[] msgBytes = msg.getBytes();
   for( int index = 0; index < msgBytes.length ; index += chunkSizeInBytes ) {
         DatagramPacket packet = new DatagramPacket( msgBytes, index, Math.min( chunkSizeInBytes, msgBytes.length-index ));
         send( packet ); // You know how that works ...
   }
}