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		????	data[i]?=?rd[i];
		????}
		????return?data;
????	}
????	
????	public?void?close（）?{
		????skt.close（）;????		
????	}
	}