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 */
017package org.apache.xbean.spring.jndi;
018
019import java.util.concurrent.ConcurrentHashMap;
020
021import org.apache.commons.logging.Log;
022import org.apache.commons.logging.LogFactory;
023import org.springframework.beans.factory.BeanFactory;
024import org.springframework.core.io.ClassPathResource;
025import org.springframework.core.io.Resource;
026import org.springframework.core.io.ResourceEditor;
027import org.apache.xbean.spring.context.impl.XBeanXmlBeanFactory;
028
029import javax.naming.Context;
030import javax.naming.NamingException;
031import javax.naming.spi.InitialContextFactory;
032
033import java.util.HashMap;
034import java.util.Hashtable;
035import java.util.Map;
036
037/**
038 * A simple JNDI initial context which loads the JNDI namespace from a spring.xml configuration file.
039 * The spring.xml configuration file can be specified by the {@link Context#PROVIDER_URL} property
040 * which can be any spring resource string (classpath://foo.xml, or file://foo/bar.xml or a URL)
041 * otherwise the jndi.xml file is found on the classpath.
042 *
043 * @version $Revision: 657 $
044 */
045public class SpringInitialContextFactory implements InitialContextFactory {
046    private static final transient Log log = LogFactory.getLog(SpringInitialContextFactory.class);
047
048    private static Map cache = new HashMap();
049
050    private static Context singleton;
051
052    /**
053     * A factory method which can be used to initialise a singleton JNDI context from inside a Spring.xml
054     * such that future calls to new InitialContext() will reuse it
055     */
056    public static Context makeInitialContext() {
057        singleton = new DefaultContext();
058        return singleton;
059    }
060
061    public Context getInitialContext(Hashtable environment) throws NamingException {
062        if (singleton != null) {
063            return singleton;
064        }
065        Resource resource = null;
066        Object value = environment.get(Context.PROVIDER_URL);
067        String key = "jndi.xml";
068        if (value == null) {
069            resource = new ClassPathResource(key);
070        }
071        else {
072            if (value instanceof Resource) {
073                resource = (Resource) value;
074            }
075            else {
076                ResourceEditor editor = new ResourceEditor();
077                key = value.toString();
078                editor.setAsText(key);
079                resource = (Resource) editor.getValue();
080            }
081        }
082        BeanFactory context = loadContext(resource, key);
083        Context answer = (Context) context.getBean("jndi");
084        if (answer == null) {
085            log.warn("No JNDI context available in JNDI resource: " + resource);
086            answer = new DefaultContext(environment, new ConcurrentHashMap());
087        }
088        return answer;
089    }
090
091    protected BeanFactory loadContext(Resource resource, String key) {
092        synchronized (cache) {
093            BeanFactory answer = (BeanFactory) cache.get(key);
094            if (answer == null) {
095                answer =  createContext(resource);
096                cache.put(key, answer);
097            }
098            return answer;
099        }
100    }
101
102    protected BeanFactory createContext(Resource resource) {
103        log.info("Loading JNDI context from: " + resource);
104        return new XBeanXmlBeanFactory(resource);
105    }
106}