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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  
18  package org.apache.commons.proxy.provider.remoting;
19  
20  import org.apache.commons.proxy.ObjectProvider;
21  import org.apache.commons.proxy.ProxyUtils;
22  import org.apache.commons.proxy.exception.ObjectProviderException;
23  
24  import javax.naming.InitialContext;
25  import javax.naming.NamingException;
26  import javax.rmi.PortableRemoteObject;
27  import java.lang.reflect.InvocationTargetException;
28  import java.lang.reflect.Method;
29  import java.util.Properties;
30  
31  /**
32   * Provides a reference to a session bean by looking up the home object and calling (via reflection) the no-argument
33   * create() method.  This will work for both local and remote session beans.
34   *
35   * @author James Carman
36   * @since 1.0
37   */
38  public class SessionBeanProvider implements ObjectProvider
39  {
40  //----------------------------------------------------------------------------------------------------------------------
41  // Fields
42  //----------------------------------------------------------------------------------------------------------------------
43      private final String jndiName;
44      private final Class homeInterface;
45      private final Properties properties;
46  
47  //----------------------------------------------------------------------------------------------------------------------
48  // Constructors
49  //----------------------------------------------------------------------------------------------------------------------
50  
51      public SessionBeanProvider( String jndiName, Class homeInterface )
52      {
53          this.jndiName = jndiName;
54          this.homeInterface = homeInterface;
55          this.properties = null;
56      }
57  
58      public SessionBeanProvider( String jndiName, Class homeInterface, Properties properties )
59      {
60          this.jndiName = jndiName;
61          this.homeInterface = homeInterface;
62          this.properties = properties;
63      }
64  
65  //----------------------------------------------------------------------------------------------------------------------
66  // ObjectProvider Implementation
67  //----------------------------------------------------------------------------------------------------------------------
68  
69      public Object getObject()
70      {
71          try
72          {
73              final InitialContext initialContext = properties == null ? new InitialContext() :
74                                                    new InitialContext( properties );
75              Object homeObject = PortableRemoteObject.narrow( initialContext.lookup( jndiName ), homeInterface );
76              final Method createMethod = homeObject.getClass().getMethod( "create", ProxyUtils.EMPTY_ARGUMENT_TYPES );
77              return createMethod.invoke( homeObject, ProxyUtils.EMPTY_ARGUMENTS );
78          }
79          catch( NoSuchMethodException e )
80          {
81              throw new ObjectProviderException(
82                      "Unable to find no-arg create() method on home interface " + homeInterface.getName() + ".", e );
83          }
84          catch( IllegalAccessException e )
85          {
86              throw new ObjectProviderException(
87                      "No-arg create() method on home interface " + homeInterface.getName() + " is not accessible.",
88                      e ); // Should never happen!
89          }
90          catch( NamingException e )
91          {
92              throw new ObjectProviderException( "Unable to lookup EJB home object in JNDI.", e );
93          }
94          catch( InvocationTargetException e )
95          {
96              throw new ObjectProviderException(
97                      "No-arg create() method on home interface " + homeInterface.getName() + " threw an exception.", e );
98          }
99      }
100 }
101