001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.activemq.jndi;
018    
019    import java.util.Enumeration;
020    import java.util.Hashtable;
021    import java.util.Properties;
022    
023    import javax.naming.Context;
024    import javax.naming.Name;
025    import javax.naming.NamingException;
026    import javax.naming.Reference;
027    import javax.naming.StringRefAddr;
028    import javax.naming.spi.ObjectFactory;
029    
030    import org.slf4j.Logger;
031    import org.slf4j.LoggerFactory;
032    
033    /**
034     * Converts objects implementing JNDIStorable into a property fields so they can
035     * be stored and regenerated from JNDI
036     */
037    public class JNDIReferenceFactory implements ObjectFactory {
038    
039        static Logger log = LoggerFactory.getLogger(JNDIReferenceFactory.class);
040    
041        /**
042         * This will be called by a JNDIprovider when a Reference is retrieved from
043         * a JNDI store - and generates the orignal instance
044         * 
045         * @param object the Reference object
046         * @param name the JNDI name
047         * @param nameCtx the context
048         * @param environment the environment settings used by JNDI
049         * @return the instance built from the Reference object
050         * @throws Exception if building the instance from Reference fails (usually
051         *                 class not found)
052         */
053        public Object getObjectInstance(Object object, Name name, Context nameCtx, Hashtable environment) throws Exception {
054            Object result = null;
055            if (object instanceof Reference) {
056                Reference reference = (Reference)object;
057    
058                if (log.isTraceEnabled()) {
059                    log.trace("Getting instance of " + reference.getClassName());
060                }
061    
062                Class theClass = loadClass(this, reference.getClassName());
063                if (JNDIStorableInterface.class.isAssignableFrom(theClass)) {
064    
065                    JNDIStorableInterface store = (JNDIStorableInterface)theClass.newInstance();
066                    Properties properties = new Properties();
067                    for (Enumeration iter = reference.getAll(); iter.hasMoreElements();) {
068    
069                        StringRefAddr addr = (StringRefAddr)iter.nextElement();
070                        properties.put(addr.getType(), (addr.getContent() == null) ? "" : addr.getContent());
071    
072                    }
073                    store.setProperties(properties);
074                    result = store;
075                }
076            } else {
077                log.error("Object " + object + " is not a reference - cannot load");
078                throw new RuntimeException("Object " + object + " is not a reference");
079            }
080            return result;
081        }
082    
083        /**
084         * Create a Reference instance from a JNDIStorable object
085         * 
086         * @param instanceClassName
087         * @param po
088         * @return
089         * @throws NamingException
090         */
091    
092        public static Reference createReference(String instanceClassName, JNDIStorableInterface po) throws NamingException {
093            if (log.isTraceEnabled()) {
094                log.trace("Creating reference: " + instanceClassName + "," + po);
095            }
096            Reference result = new Reference(instanceClassName, JNDIReferenceFactory.class.getName(), null);
097            try {
098                Properties props = po.getProperties();
099                for (Enumeration iter = props.propertyNames(); iter.hasMoreElements();) {
100                    String key = (String)iter.nextElement();
101                    String value = props.getProperty(key);
102                    javax.naming.StringRefAddr addr = new javax.naming.StringRefAddr(key, value);
103                    result.add(addr);
104                }
105            } catch (Exception e) {
106                log.error(e.getMessage(), e);
107                throw new NamingException(e.getMessage());
108            }
109            return result;
110        }
111    
112        /**
113         * Retrieve the class loader for a named class
114         * 
115         * @param thisObj
116         * @param className
117         * @return
118         * @throws ClassNotFoundException
119         */
120    
121        public static Class loadClass(Object thisObj, String className) throws ClassNotFoundException {
122            // tryu local ClassLoader first.
123            ClassLoader loader = thisObj.getClass().getClassLoader();
124            Class theClass;
125            if (loader != null) {
126                theClass = loader.loadClass(className);
127            } else {
128                // Will be null in jdk1.1.8
129                // use default classLoader
130                theClass = Class.forName(className);
131            }
132            return theClass;
133        }
134    
135    }