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 backtype.storm.messaging;
  
  import java.lang.reflect.Constructor;
  import java.lang.reflect.Method;
  import java.util.Map;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import backtype.storm.Config;
  
  public class TransportFactory {
      public static final Logger LOG = LoggerFactory.getLogger(TransportFactory.class);
  
      public static IContext makeContext(Map storm_conf) {
          // get factory class name
          String transportPluginKlassName = (String) storm_conf.get(Config.STORM_MESSAGING_TRANSPORT);
          LOG.info("JStorm peer transport plugin:" + transportPluginKlassName);
  
          IContext transport;
          try {
              // create a factory class
              Class klass = Class.forName(transportPluginKlassName);
              // obtain a context object
              // Object obj = klass.newInstance();
              Constructor constructor = klass.getDeclaredConstructor();
              constructor.setAccessible(true);
              Object obj = constructor.newInstance();
              LOG.info("TransportFactory makeContext: new klass: " + obj);
              if (obj instanceof IContext) {
                  // case 1: plugin is a IContext class
                  transport = (IContext) obj;
                  // initialize with storm configuration
                  transport.prepare(storm_conf);
                  LOG.info("TransportFactory makeContext: start prepare... " + storm_conf);
              } else {
                  // case 2: Non-IContext plugin must have a
                  // makeContext(storm_conf) method that returns IContext object
                  Method method = klass.getMethod("makeContext", Map.class);
                  LOG.debug("object:" + obj + " method:" + method);
                  transport = (IContext) method.invoke(obj, storm_conf);
              }
              LOG.info("TransportFactory makeContext done...");
          } catch (Exception e) {
              throw new RuntimeException("Fail to construct messaging plugin from plugin " + transportPluginKlassName, e);
          }
          return transport;
      }
  
  }
  