Use Datagram in J2ME : Datagram « J2ME « Java Tutorial

1. Java Tutorial
2. J2ME
3. Datagram

import javax.microedition.io.Connector;
import javax.microedition.io.Datagram;
import javax.microedition.io.DatagramConnection;

public class J2MEDatagramSender {
  public static void main(String[] args) throws Exception {
    DatagramConnection sender = (DatagramConnection) Connector
        .open("datagram://localhost:8080");
    int length = 100;
    byte[] buffer = new byte[length];
    for (int i = 0; i < length; i++) {
      buffer[i] = (byte) ('0' + (i % 10));
    }
    Datagram dgram = sender.newDatagram(buffer, buffer.length);
    sender.send(dgram);

    for (int i = 0; i < length; i++) {
      buffer[i] = (byte) 0;
    }
    sender.receive(dgram);
    length = dgram.getLength();
    System.out.println("Received return packet, length is " + length);
    for (int i = 0; i < length; i++) {
      System.out.print(buffer[i] + " ");
    }
  }
}