/*
* Copyright 2002-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.integration.ip.udp;
import java.io.IOException;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.MulticastSocket;
import org.springframework.messaging.MessagingException;
/**
* Channel adapter that joins a multicast group and receives incoming packets and
* sends them to an output channel.
*
* @author Gary Russell
* @author Marcin Pilaczynski
* @since 2.0
*/
public class MulticastReceivingChannelAdapter extends UnicastReceivingChannelAdapter {
private final String group;
/**
* Constructs a MulticastReceivingChannelAdapter that listens for packets on the
* specified multichannel address (group) and port.
* @param group The multichannel address.
* @param port The port.
*/
public MulticastReceivingChannelAdapter(String group, int port) {
super(port);
this.group = group;
}
/**
* Constructs a MulticastReceivingChannelAdapter that listens for packets on the
* specified multichannel address (group) and port. Enables setting the lengthCheck
* option, which expects a length to precede the incoming packets.
* @param group The multichannel address.
* @param port The port.
* @param lengthCheck If true, enables the lengthCheck Option.
*/
public MulticastReceivingChannelAdapter(String group, int port, boolean lengthCheck) {
super(port, lengthCheck);
this.group = group;
}
@Override
public synchronized DatagramSocket getSocket() {
if (getTheSocket() == null) {
try {
int port = getPort();
MulticastSocket socket = port == 0 ? new MulticastSocket() : new MulticastSocket(port);
String localAddress = this.getLocalAddress();
if (localAddress != null) {
InetAddress whichNic = InetAddress.getByName(localAddress);
socket.setInterface(whichNic);
}
setSocketAttributes(socket);
socket.joinGroup(InetAddress.getByName(this.group));
setSocket(socket);
}
catch (IOException e) {
throw new MessagingException("failed to create DatagramSocket", e);
}
}
return super.getSocket();
}
}