core/src/main/java/org/apache/struts/chain/commands/AbstractExecuteAction.java

/*
 * $Id$
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.struts.chain.commands;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.chain.contexts.ActionContext;
import org.apache.struts.config.ActionConfig;
import org.apache.struts.config.ForwardConfig;

/**
 * <p>Invoke the appropriate <code>Action</code> for this request, and cache
 * the returned <code>ActionForward</code>.</p>
 *
 * @version $Rev$
 * @see ExecuteDispatcher
 * @since Struts 1.3
 */
public abstract class AbstractExecuteAction extends ActionCommandBase {
    // ---------------------------------------------------------- Public Methods

    /**
     * <p>Invoke the appropriate <code>Action</code> for this request 
     * if a dispatcher is not available, and cache the returned 
     * <code>ActionForward</code>.</p>
     *
     * @param actionCtx The <code>Context</code> for the current request
     * @return <code>false</code> so that processing continues
     * @throws Exception if thrown by the Action class
     */
    public boolean execute(ActionContext actionCtx)
        throws Exception {
	
        // Skip processing if the current request is not valid
        Boolean valid = actionCtx.getFormValid();
        if ((valid == null) || !valid.booleanValue()) {
            return CONTINUE_PROCESSING;
        }
        
        // Skip processing if a dispatcher is available
        ActionConfig actionConfig = actionCtx.getActionConfig();
        if (actionConfig.getDispatcher() != null) {
            return CONTINUE_PROCESSING;
        }

        // Acquire the resources we will need to send to the Action
        Action action = actionCtx.getAction();
        if (action == null) {
            return CONTINUE_PROCESSING;
        }

        ActionForm actionForm = actionCtx.getActionForm();

        // Execute the Action for this request, caching returned ActionForward
        ForwardConfig forwardConfig =
            execute(actionCtx, action, actionConfig, actionForm);

        actionCtx.setForwardConfig(forwardConfig);

        return CONTINUE_PROCESSING;
    }

    // ------------------------------------------------------- Protected Methods

    /**
     * <p>Execute the specified <code>Action</code>, and return the resulting
     * <code>ForwardConfig</code>.</p>
     *
     * @param context      The <code>Context</code> for this request
     * @param action       The <code>Action</code> to be executed
     * @param actionConfig The <code>ActionConfig</code> defining this action
     * @param actionForm   The <code>ActionForm</code> (if any) for this
     *                     action
     * @return ForwardConfig The next location, or null
     * @throws Exception if thrown by the <code>Action</code>
     */
    protected abstract ForwardConfig execute(ActionContext context,
        Action action, ActionConfig actionConfig, ActionForm actionForm)
        throws Exception;
}