/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.geronimo.farm.discovery.multicast;
import java.net.URI;
import java.net.MulticastSocket;
import java.net.InetAddress;
import java.net.DatagramPacket;
import java.net.SocketException;
import java.util.concurrent.TimeUnit;
import java.io.IOException;
/**
* @version $Rev$ $Date$
*/
public class MulticastSearch {
private static final int BUFF_SIZE = 8192;
private final MulticastSocket multicast;
public MulticastSearch() throws IOException {
this("239.255.3.2", 6142);
}
public MulticastSearch(String host, int port) throws IOException {
InetAddress inetAddress = InetAddress.getByName(host);
multicast = new MulticastSocket(port);
multicast.joinGroup(inetAddress);
multicast.setSoTimeout(500);
}
public URI search(int timeout, TimeUnit milliseconds) throws IOException {
return search(new DefaultFilter(), timeout, milliseconds);
}
public URI search() throws IOException {
return search(new DefaultFilter(), 0, TimeUnit.MILLISECONDS);
}
public URI search(Filter filter) throws IOException {
return search(filter, 0, TimeUnit.MILLISECONDS);
}
public URI search(Filter filter, long timeout, TimeUnit unit) throws IOException {
timeout = unit.convert(timeout, TimeUnit.MILLISECONDS);
long waited = 0;
byte[] buf = new byte[BUFF_SIZE];
DatagramPacket packet = new DatagramPacket(buf, 0, buf.length);
while (timeout == 0 || waited < timeout){
long start = System.currentTimeMillis();
try {
multicast.receive(packet);
if (packet.getLength() > 0) {
String str = new String(packet.getData(), packet.getOffset(), packet.getLength());
URI service = URI.create(str);
if (service != null && filter.accept(service)) {
return service;
}
}
} catch (SocketException e) {
} finally {
long stop = System.currentTimeMillis();
waited += stop - start;
}
}
return null;
}
public interface Filter {
boolean accept(URI service);
}
public static class DefaultFilter implements Filter {
public boolean accept(URI service) {
return true;
}
}
}