Save This Page
Home » activemq-parent-5.3.1-source-release » org.apache » activemq » transport » discovery » rendezvous » [javadoc | source]
    1   /**
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements.  See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache License, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License.  You may obtain a copy of the License at
    8    *
    9    *      http://www.apache.org/licenses/LICENSE-2.0
   10    *
   11    * Unless required by applicable law or agreed to in writing, software
   12    * distributed under the License is distributed on an "AS IS" BASIS,
   13    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   14    * See the License for the specific language governing permissions and
   15    * limitations under the License.
   16    */
   17   package org.apache.activemq.transport.discovery.rendezvous;
   18   
   19   import java.io.IOException;
   20   import java.net.InetAddress;
   21   import java.util.HashMap;
   22   import java.util.Map;
   23   import java.util.concurrent.atomic.AtomicInteger;
   24   import org.apache.activemq.jmdns.JmDNS;
   25   
   26   public final class JmDNSFactory {
   27   
   28       static Map<InetAddress, UsageTracker> registry = new HashMap<InetAddress, UsageTracker>();
   29   
   30       static class UsageTracker {
   31           AtomicInteger count = new AtomicInteger(0);
   32           JmDNS jmDNS;
   33       }
   34   
   35       private JmDNSFactory() {        
   36       }
   37       
   38       static synchronized JmDNS create(final InetAddress address) throws IOException {
   39           UsageTracker tracker = registry.get(address);
   40           if (tracker == null) {
   41               tracker = new UsageTracker();
   42               tracker.jmDNS = new JmDNS(address) {
   43                   public void close() {
   44                       if (onClose(address)) {
   45                           super.close();
   46                       }
   47                   }
   48               };
   49               registry.put(address, tracker);
   50           }
   51           tracker.count.incrementAndGet();
   52           return tracker.jmDNS;
   53       }
   54   
   55       static synchronized boolean onClose(InetAddress address) {
   56           UsageTracker tracker = registry.get(address);
   57           if (tracker != null) {
   58               if (tracker.count.decrementAndGet() == 0) {
   59                   registry.remove(address);
   60                   return true;
   61               }
   62           }
   63           return false;
   64       }
   65   }

Save This Page
Home » activemq-parent-5.3.1-source-release » org.apache » activemq » transport » discovery » rendezvous » [javadoc | source]