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/**
* 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.openejb.client;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.MulticastSocket;
import java.net.SocketException;
import java.net.SocketTimeoutException;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.concurrent.TimeUnit;
/**
* @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(final String host, final int port) throws IOException {
final InetAddress inetAddress = InetAddress.getByName(host);
multicast = new MulticastSocket(port);
multicast.joinGroup(inetAddress);
multicast.setSoTimeout(500);
}
@Override
protected void finalize() throws Throwable {
try {
this.close();
} finally {
super.finalize();
}
}
public URI search(final int timeout, final 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(final Filter filter) throws IOException {
return search(filter, 0, TimeUnit.MILLISECONDS);
}
@SuppressWarnings("UseOfSystemOutOrSystemErr")
public URI search(final Filter filter, long timeout, final TimeUnit unit) throws IOException {
timeout = TimeUnit.MILLISECONDS.convert(timeout, unit);
long waited = 0;
final byte[] buf = new byte[BUFF_SIZE];
final DatagramPacket packet = new DatagramPacket(buf, 0, buf.length);
while (timeout == 0 || waited < timeout) {
final long start = System.currentTimeMillis();
try {
multicast.receive(packet);
if (packet.getLength() > 0) {
final String str = new String(packet.getData(), packet.getOffset(), packet.getLength());
try {
final URI service = new URI(str);
if (service != null && filter.accept(service)) {
final String callerHost = ((InetSocketAddress) packet.getSocketAddress()).getAddress().getHostAddress();
final String serviceHost = service.getHost();
if (MulticastPulseClient.isLocalAddress(serviceHost, false)) {
if (!MulticastPulseClient.isLocalAddress(callerHost, false)) {
//A local service is only available to a local client
continue;
}
}
return service;
}
} catch (final URISyntaxException e) {
// not a service URI
}
}
} catch (final SocketTimeoutException e) {
//Ignore
} catch (final SocketException e) {
System.out.println(e.getClass().getName() + ": " + e.getMessage());
} finally {
final long stop = System.currentTimeMillis();
waited += stop - start;
}
}
return null;
}
public void close() {
try {
multicast.close();
} catch (final Throwable e) {
//Ignore
}
}
public interface Filter {
boolean accept(URI service);
}
public static class DefaultFilter implements Filter {
@Override
public boolean accept(final URI service) {
return true;
}
}
}
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