Source Code Cross Referenced for NamingInputModule.java in  » Content-Management-System » apache-lenya-2.0 » org » apache » cocoon » components » modules » input » Java Source Code / Java DocumentationJava Source Code and Java Documentation

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.cocoon.components.modules.input;
018:
019:        import org.apache.avalon.framework.activity.Initializable;
020:        import org.apache.avalon.framework.configuration.Configuration;
021:        import org.apache.avalon.framework.configuration.ConfigurationException;
022:        import org.apache.avalon.framework.thread.ThreadSafe;
023:
024:        import javax.naming.InitialContext;
025:        import javax.naming.NamingException;
026:        import java.util.Collections;
027:        import java.util.Iterator;
028:        import java.util.Map;
029:        import java.util.Properties;
030:
031:        /**
032:         * NamingInputModule accesses values stored in the JNDI context.
033:         *
034:         * <p>This module accept any configuration parameters and passes them as
035:         * properties to the InitialContext. When connecting to the Naming context
036:         * of the server Cocoon is running in, no parameters are required.</p>
037:         *
038:         * <p>Example module configuration when connecting to external WebLogic server:
039:         * <pre>
040:         *   &lt;java.naming.factory.initial&gt;weblogic.jndi.WLInitialContextFactory&lt;/java.naming.factory.initial&gt;
041:         *   &lt;java.naming.provider.url&gt;t3://localhost:7001&lt;/java.naming.provider.url&gt;
042:         * </pre>
043:         *
044:         * <p>Example usage:
045:         * <pre>
046:         *   &lt;map:generate src="{naming:java:comp/env/greeting}"/&gt;
047:         * </pre>
048:         * This lookups <code>greeting</code> entry from the environment of the webapp.
049:         * Webapp's web.xml should define this entry:
050:         * <pre>
051:         *   &lt;env-entry&gt;
052:         *     &lt;env-entry-name&gt;greeting&lt;/env-entry-name&gt;
053:         *     &lt;env-entry-value&gt;Hello, World&lt;/env-entry-value&gt;
054:         *     &lt;env-entry-type&gt;java.lang.String&lt;/env-entry-type&gt;
055:         *   &lt;/env-entry&gt;
056:         * </pre>
057:         *
058:         * @author <a href="mailto:vgritsenko@apache.org">Vadim Gritsenko</a>
059:         * @version $Id: NamingInputModule.java 36239 2004-08-11 18:28:06Z vgritsenko $
060:         */
061:        public class NamingInputModule extends AbstractInputModule implements 
062:                ThreadSafe, Initializable {
063:
064:            /**
065:             * Initial context properties.
066:             */
067:            private Properties properties;
068:
069:            /**
070:             * Initial context.
071:             */
072:            private InitialContext context;
073:
074:            /**
075:             * Fill in InitialContext properties from passed configuration.
076:             */
077:            public void configure(Configuration conf)
078:                    throws ConfigurationException {
079:                Configuration[] parameters = conf.getChildren();
080:                this .properties = new Properties();
081:                for (int i = 0; i < parameters.length; i++) {
082:                    String key = parameters[i].getName();
083:                    String val = parameters[i].getValue("");
084:                    this .properties.put(key, val);
085:                }
086:            }
087:
088:            /**
089:             * Creates InitialContext with configured properties.
090:             */
091:            public void initialize() throws Exception {
092:                this .context = new InitialContext(this .properties);
093:            }
094:
095:            /**
096:             * Close InitialContext.
097:             */
098:            public void dispose() {
099:                super .dispose();
100:                if (this .context != null) {
101:                    try {
102:                        this .context.close();
103:                    } catch (NamingException ignored) {
104:                    }
105:                }
106:            }
107:
108:            /**
109:             * Look up <code>name</code> from the InitialContext.
110:             */
111:            public Object getAttribute(String name, Configuration modeConf,
112:                    Map objectModel) throws ConfigurationException {
113:
114:                // Why properties can override passed name parameter? See RequestParameterModule
115:                String pname = (String) this .properties.get("path");
116:                if (pname == null) {
117:                    pname = name;
118:                }
119:
120:                if (modeConf != null) {
121:                    pname = modeConf.getAttribute("path", pname);
122:                    // preferred
123:                    pname = modeConf.getChild("path").getValue(pname);
124:                }
125:
126:                try {
127:                    return this .context.lookup(pname);
128:                } catch (NamingException e) {
129:                    if (getLogger().isDebugEnabled()) {
130:                        getLogger().debug("Can't get parameter " + pname, e);
131:                    }
132:                    return null;
133:                }
134:            }
135:
136:            /**
137:             * Returns empty iterator
138:             */
139:            public Iterator getAttributeNames(Configuration modeConf,
140:                    Map objectModel) throws ConfigurationException {
141:
142:                return Collections.EMPTY_LIST.iterator();
143:            }
144:        }