Subversion Repositories udp_ip_stack

package com.pjf;

import java.io.IOException;

import java.net.DatagramPacket;

import java.net.DatagramSocket;

import java.net.InetAddress;

import java.net.SocketException;

import java.net.UnknownHostException;

public class UDPCxn {

        private DatagramSocket skt;

        private InetAddress dstIP;

        public UDPCxn(long dstIPadr) throws SocketException, UnknownHostException {

                skt = new DatagramSocket();

                        byte[] target = new byte[4];

                        target[0] = (byte) ((dstIPadr >> 24) & 0xff);

                        target[1] = (byte) ((dstIPadr >> 16) & 0xff);

                        target[2] = (byte) ((dstIPadr >> 8) & 0xff);

                        target[3] = (byte) (dstIPadr & 0xff);

                        dstIP = InetAddress.getByAddress(target);

        }

        public UDPCxn(String dstIPadr) throws SocketException, UnknownHostException {

                skt = new DatagramSocket();

                String[] parts = dstIPadr.split("[.]");

                if (parts.length != 4) {

                        throw new UnknownHostException("ip addr must have 4 parts");

                }

                        byte[] target = new byte[4];

                        for (int i = 0; i<4; i++) {

                                target[i] = (byte) Integer.parseInt(parts[i]);

                        }

                        dstIP = InetAddress.getByAddress(target);

        }

        public void send(byte[] data, int port) throws IOException {

                DatagramPacket pkt = new DatagramPacket(data, data.length, dstIP, port);

                System.out.println("Sending packet");

                skt.send(pkt);

        }

        public void fixSend(String str, int port, boolean print) throws IOException {

                String s1 = str.replace('~','\001');

                byte[] data = s1.getBytes();

                DatagramPacket pkt = new DatagramPacket(data, data.length, dstIP, port);

                if (print) {

                        System.out.println("Sending packet: " + str + " on port " + port);

                }

                skt.send(pkt);

        }

        public byte[] rcv() throws IOException {

                byte[] buf = new byte[1024];

                    DatagramPacket pkt = new DatagramPacket(buf, buf.length);

//                  System.out.println("waiting to receive ...");

                    skt.receive(pkt);

                    int len = pkt.getLength();

                    byte[] rd = pkt.getData();

                byte[] data = new byte[len];

                    for (int i=0; i<len; i++) {

                        data[i] = rd[i];

                    }

                    return data;

        }

        public void close() {

                    skt.close();

        }

        }