001    package org.apache.turbine.pipeline;
002    
003    
004    /*
005     * Licensed to the Apache Software Foundation (ASF) under one
006     * or more contributor license agreements.  See the NOTICE file
007     * distributed with this work for additional information
008     * regarding copyright ownership.  The ASF licenses this file
009     * to you under the Apache License, Version 2.0 (the
010     * "License"); you may not use this file except in compliance
011     * with the License.  You may obtain a copy of the License at
012     *
013     *   http://www.apache.org/licenses/LICENSE-2.0
014     *
015     * Unless required by applicable law or agreed to in writing,
016     * software distributed under the License is distributed on an
017     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
018     * KIND, either express or implied.  See the License for the
019     * specific language governing permissions and limitations
020     * under the License.
021     */
022    
023    
024    import java.io.IOException;
025    
026    import org.apache.commons.logging.Log;
027    import org.apache.commons.logging.LogFactory;
028    import org.apache.turbine.util.RunData;
029    import org.apache.turbine.util.TurbineException;
030    import org.apache.turbine.util.uri.URIConstants;
031    
032    /**
033     * This valve is responsible for setting the 'action' property of RunData based
034     * on request parameter. There is no default action, since a null action is
035     * perfectly valid.
036     *
037     * @author <a href="mailto:james@jamestaylor.org">James Taylor</a>
038     * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
039     */
040    public class DetermineActionValve
041        extends AbstractValve
042    {
043        private static final Log log
044            = LogFactory.getLog(DetermineActionValve.class);
045    
046        /**
047         * @see org.apache.turbine.Valve#invoke(RunData, ValveContext)
048         */
049        public void invoke(PipelineData pipelineData, ValveContext context)
050            throws IOException, TurbineException
051        {
052            RunData data = getRunData(pipelineData);
053            if (! data.hasAction())
054            {
055                String action =
056                    data.getParameters().getString(URIConstants.CGI_ACTION_PARAM);
057    
058                if (action != null)
059                {
060                    data.setAction(action);
061    
062                    log.debug("Set action from request parameter");
063                }
064                else
065                {
066                    log.debug("No action");
067                }
068            }
069    
070            if (log.isDebugEnabled())
071            {
072                log.debug("Action is now: " + data.getAction());
073            }
074    
075            // Pass control to the next Valve in the Pipeline
076            context.invokeNext(pipelineData);
077        }
078    }