package com.bwssystems.util;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class UDPDatagramSender {
private Logger log = LoggerFactory.getLogger(UDPDatagramSender.class);
private DatagramSocket responseSocket = null;
private int udpResponsePort;
public UDPDatagramSender() {
super();
udpResponsePort = 0;
}
public static UDPDatagramSender createUDPDatagramSender(int udpResponsePort) {
UDPDatagramSender aDatagramSender = new UDPDatagramSender();
if(aDatagramSender.initializeSocket(udpResponsePort))
return aDatagramSender;
else
return null;
}
private boolean initializeSocket(int port) {
log.info("Initializing UDP response Socket...");
udpResponsePort = port;
boolean portLoopControl = true;
int retryCount = 0;
while(portLoopControl) {
try {
responseSocket = new DatagramSocket(udpResponsePort);
portLoopControl = false;
} catch(SocketException e) {
if(retryCount == 0)
log.warn("UDP Response Port is in use, starting loop to find open port for 20 tries - configured port is: " + udpResponsePort);
if(retryCount >= 20) {
portLoopControl = false;
log.error("UDP Response Port issue, could not find open port - last port tried: " + udpResponsePort + " with message: " + e.getMessage());
return false;
}
}
if(portLoopControl) {
retryCount++;
udpResponsePort++;
}
}
log.info("UDP response Seocket initialized to: " + udpResponsePort);
return true;
}
public int getUdpResponsePort() {
return udpResponsePort;
}
public void closeResponseSocket() {
responseSocket.close();
}
public void sendUDPResponse(String udpResponse, InetAddress requester, int sourcePort) throws IOException {
log.debug("Sending response string: <<<" + udpResponse + ">>>");
if(responseSocket == null)
throw new IOException("Socket not initialized");
DatagramPacket response = new DatagramPacket(udpResponse.getBytes(), udpResponse.length(), requester, sourcePort);
responseSocket.send(response);
}
}