What class that can implement file transfer in j2sdk

Question

hi
i am doing this project that can transfer file through LAN(much like Yahoo Messenger)
is there a class in j2sdk that can implement this? how to do it?
thanks>>>>

Answer 1

Annie is right that if you use only j2sdk then you want to use java.net. If you want to do it an easier way you can use ftp and download open source code. There are a couple of free packages you can find at http://www.javaworld.com/javaworld/jw-04-2003/jw-0404-ftp-p2.html
If you want to use only the j2sdk then these 2 classes will give you an example of how to transfer data on the net. You need to add a lot more code to make these useful but it gives the general idea of how to open a socket and tranfser a bit of data.
Client Side
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class ClientClass {
     private final static String HOST = "10.133.5.230";
     private final static int PORT = 543;
     public void sendFile() {
          try {
               System.out.println("Entered sendFile");
               Socket socket = new Socket( HOST, PORT);
               InputStreamReader input = new InputStreamReader(socket
                         .getInputStream());
               PrintWriter output = new PrintWriter(socket.getOutputStream(), true);
               output.println("This is a test");
               output.println("This is a test 2");
               output.println("Last line");
               output.println("ENDEND");
               socket.close();
          } catch (Exception ex) {
               ex.printStackTrace();
     public static void main(String[] args) {
          ClientClass client = new ClientClass();
          client.sendFile();
}Server Side
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class ServerClass {
     private final static String HOST = "10.133.5.230";
     private final static int PORT = 543;
     public void getFile() {
          char[] inbuf = new char[2048];
          try {
               System.out.println("Entered getFile");
               // open server
               ServerSocket server = new ServerSocket(PORT);
               // wait for client.
               Socket client = server.accept();
               InputStreamReader inputStream = new InputStreamReader(client
                         .getInputStream());
               BufferedReader input = new BufferedReader(inputStream);
               PrintWriter output = new PrintWriter(client.getOutputStream());
               while (true) {
                    String inData = input.readLine();
                    if ((inData != null) && (inData.length() > 0)) {
                         System.out.println("got '" + inData + "'");
                         if (inData.indexOf("ENDEND") > -1) {
                              client.close();
                              server.close();
                              System.exit(0);
          } catch (Exception ex) {
               ex.printStackTrace();
     public static void main(String[] args) {
          ServerClass server = new ServerClass();
          server.getFile();
}Start the server side first and then run the client code in a separate JVM.
You will also need to add the ability to handle binary and some sort of protocol to transfer the file names and handle the exceptions much better. Doing it like this would be much more fun and challenging, with ftp it would be alot faster.