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1   /*** 
2    * 
3    * Copyright 2004 Protique Ltd
4    * 
5    * Licensed under the Apache License, Version 2.0 (the "License"); 
6    * you may not use this file except in compliance with the License. 
7    * 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  
19  package org.codehaus.activemq.jndi;
20  
21  import org.apache.commons.logging.Log;
22  import org.apache.commons.logging.LogFactory;
23  
24  import javax.naming.Context;
25  import javax.naming.Name;
26  import javax.naming.NamingException;
27  import javax.naming.Reference;
28  import javax.naming.StringRefAddr;
29  import javax.naming.spi.ObjectFactory;
30  import java.util.Enumeration;
31  import java.util.Hashtable;
32  import java.util.Properties;
33  
34  /***
35   * Converts objects implementing JNDIStorable into a property fields so they can
36   * be stored and regenerated from JNDI
37   */
38  public class JNDIReferenceFactory implements ObjectFactory {
39  
40      static Log log = LogFactory.getLog(JNDIReferenceFactory.class);
41  
42      /***
43       * This will be called by a JNDIprovider when a Reference is retrieved from
44       * a JNDI store - and generates the orignal instance
45       *
46       * @param object      the Reference object
47       * @param name        the JNDI name
48       * @param nameCtx     the context
49       * @param environment the environment settings used by JNDI
50       * @return the instance built from the Reference object
51       * @throws Exception if building the instance from Reference fails (usually class
52       *                   not found)
53       */
54      public Object getObjectInstance(Object object, Name name, Context nameCtx, Hashtable environment) throws Exception {
55          Object result = null;
56          if (object instanceof Reference) {
57              Reference reference = (Reference) object;
58  
59              if (log.isTraceEnabled()) {
60                  log.trace("Getting instance of " + reference.getClassName());
61              }
62  
63              Class theClass = loadClass(this, reference.getClassName());
64              if (JNDIStorableInterface.class.isAssignableFrom(theClass)) {
65  
66                  JNDIStorableInterface store = (JNDIStorableInterface) theClass.newInstance();
67                  Properties properties = new Properties();
68                  for (Enumeration iter = reference.getAll(); iter.hasMoreElements();) {
69  
70                      StringRefAddr addr = (StringRefAddr) iter.nextElement();
71                      properties.put(addr.getType(), (addr.getContent() == null) ? "" : addr.getContent());
72  
73                  }
74                  store.setProperties(properties);
75                  result = store;
76              }
77          }
78          else {
79              log.error("Object " + object + " is not a reference - cannot load");
80              throw new RuntimeException("Object " + object + " is not a reference");
81          }
82          return result;
83      }
84  
85      /***
86       * Create a Reference instance from a JNDIStorable object
87       *
88       * @param instanceClassName
89       * @param po
90       * @return @throws
91       *         NamingException
92       */
93  
94      public static Reference createReference(String instanceClassName, JNDIStorableInterface po) throws NamingException {
95          if (log.isTraceEnabled()) {
96              log.trace("Creating reference: " + instanceClassName + "," + po);
97          }
98          Reference result = new Reference(instanceClassName, JNDIReferenceFactory.class.getName(), null);
99          try {
100             Properties props = po.getProperties();
101             for (Enumeration iter = props.propertyNames(); iter.hasMoreElements();) {
102                 String key = (String) iter.nextElement();
103                 String value = props.getProperty(key);
104                 javax.naming.StringRefAddr addr = new javax.naming.StringRefAddr(key, value);
105                 result.add(addr);
106             }
107         }
108         catch (Exception e) {
109             log.error(e.getMessage(), e);
110             throw new NamingException(e.getMessage());
111         }
112         return result;
113     }
114 
115     /***
116      * Retrieve the class loader for a named class
117      *
118      * @param thisObj
119      * @param className
120      * @return @throws
121      *         ClassNotFoundException
122      */
123 
124     public static Class loadClass(Object thisObj, String className) throws ClassNotFoundException {
125         // tryu local ClassLoader first.
126         ClassLoader loader = thisObj.getClass().getClassLoader();
127         Class theClass;
128         if (loader != null) {
129             theClass = loader.loadClass(className);
130         }
131         else {
132             // Will be null in jdk1.1.8
133             // use default classLoader
134             theClass = Class.forName(className);
135         }
136         return theClass;
137     }
138 
139 }
140