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1   /*
2    * $Id: CreateActionForm.java 471754 2006-11-06 14:55:09Z husted $
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *  http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  package org.apache.struts.chain.commands;
22  
23  import org.apache.commons.logging.Log;
24  import org.apache.commons.logging.LogFactory;
25  import org.apache.struts.action.ActionForm;
26  import org.apache.struts.chain.contexts.ActionContext;
27  import org.apache.struts.chain.contexts.ServletActionContext;
28  import org.apache.struts.config.ActionConfig;
29  import org.apache.struts.config.FormBeanConfig;
30  
31  import java.util.Map;
32  
33  /**
34   * <p>Create (if necessary) and cache a form bean for this request.</p>
35   *
36   * @version $Id: CreateActionForm.java 471754 2006-11-06 14:55:09Z husted $
37   */
38  public class CreateActionForm extends ActionCommandBase {
39      // ------------------------------------------------------ Instance Variables
40  
41      /**
42       * <p> Provide Commons Logging instance for this class. </p>
43       */
44      private static final Log LOG = LogFactory.getLog(CreateActionForm.class);
45  
46      // ---------------------------------------------------------- Public Methods
47  
48      /**
49       * <p>Create (if necessary) and cache a form bean for this request.</p>
50       *
51       * @param actionCtx The <code>Context</code> for the current request
52       * @return <code>false</code> so that processing continues
53       * @throws Exception on any error
54       */
55      public boolean execute(ActionContext actionCtx)
56          throws Exception {
57          // Is there a form bean associated with this ActionConfig?
58          ActionConfig actionConfig = actionCtx.getActionConfig();
59          String name = actionConfig.getName();
60  
61          if (name == null) {
62              actionCtx.setActionForm(null);
63  
64              return (false);
65          }
66  
67          if (LOG.isTraceEnabled()) {
68              LOG.trace("Look up form-bean " + name);
69          }
70  
71          // Look up the corresponding FormBeanConfig (if any)
72          FormBeanConfig formBeanConfig =
73              actionConfig.getModuleConfig().findFormBeanConfig(name);
74  
75          if (formBeanConfig == null) {
76              LOG.warn("No FormBeanConfig found in module "
77                  + actionConfig.getModuleConfig().getPrefix() + " under name "
78                  + name);
79              actionCtx.setActionForm(null);
80  
81              return (false);
82          }
83  
84          Map scope = actionCtx.getScope(actionConfig.getScope());
85  
86          ActionForm instance;
87  
88          instance = (ActionForm) scope.get(actionConfig.getAttribute());
89  
90          // Can we recycle the existing instance (if any)?
91          if (!formBeanConfig.canReuse(instance)) {
92              instance = formBeanConfig.createActionForm(actionCtx);
93          }
94  
95          // TODO: Remove ServletActionContext when ActionForm no longer
96          //  directly depends on ActionServlet
97          if (actionCtx instanceof ServletActionContext) {
98              // The servlet property of ActionForm is transient, so
99              // ActionForms which are restored from a serialized state
100             // need to have their servlet restored.
101             ServletActionContext sac = (ServletActionContext) actionCtx;
102 
103             instance.setServlet(sac.getActionServlet());
104         }
105 
106         actionCtx.setActionForm(instance);
107 
108         scope.put(actionConfig.getAttribute(), instance);
109 
110         return (false);
111     }
112 }