content: /**
   * 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.activemq.transport.discovery;
  
  import java.io.IOException;
  import java.net.URI;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  
  import org.apache.activemq.util.FactoryFinder;
  import org.apache.activemq.util.IOExceptionSupport;
  
  public abstract class DiscoveryAgentFactory {
  
      private static final FactoryFinder DISCOVERY_AGENT_FINDER = new FactoryFinder("META-INF/services/org/apache/activemq/transport/discoveryagent/");
      private static final ConcurrentMap<String, DiscoveryAgentFactory> DISCOVERY_AGENT_FACTORYS = new ConcurrentHashMap<String, DiscoveryAgentFactory>();
  
      /**
       * @param uri
       * @return
       * @throws IOException
       */
      private static DiscoveryAgentFactory findDiscoveryAgentFactory(URI uri) throws IOException {
          String scheme = uri.getScheme();
          if (scheme == null) {
              throw new IOException("DiscoveryAgent scheme not specified: [" + uri + "]");
          }
          DiscoveryAgentFactory daf = DISCOVERY_AGENT_FACTORYS.get(scheme);
          if (daf == null) {
              // Try to load if from a META-INF property.
              try {
                  daf = (DiscoveryAgentFactory)DISCOVERY_AGENT_FINDER.newInstance(scheme);
                  DISCOVERY_AGENT_FACTORYS.put(scheme, daf);
              } catch (Throwable e) {
                  throw IOExceptionSupport.create("DiscoveryAgent scheme NOT recognized: [" + scheme + "]", e);
              }
          }
          return daf;
      }
  
      public static DiscoveryAgent createDiscoveryAgent(URI uri) throws IOException {
          DiscoveryAgentFactory tf = findDiscoveryAgentFactory(uri);
          return tf.doCreateDiscoveryAgent(uri);
  
      }
  
      protected abstract DiscoveryAgent doCreateDiscoveryAgent(URI uri) throws IOException;
      // {
      // try {
      // String type = ( uri.getScheme() == null ) ? uri.getPath() :
      // uri.getScheme();
      // DiscoveryAgent rc = (DiscoveryAgent)
      // discoveryAgentFinder.newInstance(type);
      // Map options = URISupport.parseParamters(uri);
      // IntrospectionSupport.setProperties(rc, options);
      // if( rc.getClass() == SimpleDiscoveryAgent.class ) {
      // CompositeData data = URISupport.parseComposite(uri);
      // ((SimpleDiscoveryAgent)rc).setServices(data.getComponents());
      // }
      // return rc;
      // } catch (Throwable e) {
      // throw IOExceptionSupport.create("Could not create discovery agent: "+uri,
      // e);
      // }
      // }
  }
  