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1   /*
2    * $Id: ValueStackShadowMap.java 471756 2006-11-06 15:01:43Z 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.struts2.views.jasperreports;
22  
23  import com.opensymphony.xwork2.util.ValueStack;
24  
25  import java.util.HashMap;
26  import java.util.Set;
27  
28  
29  /***
30   * Ported to Struts:
31   *
32   */
33  public class ValueStackShadowMap extends HashMap {
34  
35      private static final long serialVersionUID = -167109778490907240L;
36  
37      /***
38       * valueStack reference
39       */
40      ValueStack valueStack;
41  
42      /***
43       * entries reference
44       */
45      Set entries;
46  
47  
48      /***
49       * Constructs an instance of ValueStackShadowMap.
50       *
51       * @param valueStack - the underlying valuestack
52       */
53      public ValueStackShadowMap(ValueStack valueStack) {
54          this.valueStack = valueStack;
55      }
56  
57  
58      /***
59       * Implementation of containsKey(), overriding HashMap implementation.
60       *
61       * @param key - The key to check in HashMap and if not found to check on valueStack.
62       * @return <tt>true</tt>, if conatins key, <tt>false</tt> otherwise.
63       * @see java.util.HashMap#containsKey
64       */
65      public boolean containsKey(Object key) {
66          boolean hasKey = super.containsKey(key);
67  
68          if (!hasKey) {
69              if (valueStack.findValue((String) key) != null) {
70                  hasKey = true;
71              }
72          }
73  
74          return hasKey;
75      }
76  
77      /***
78       * Implementation of get(), overriding HashMap implementation.
79       *
80       * @param key - The key to get in HashMap and if not found there from the valueStack.
81       * @return value - The object from HashMap or if null, from the valueStack.
82       * @see java.util.HashMap#get
83       */
84      public Object get(Object key) {
85          Object value = super.get(key);
86  
87          if ((value == null) && key instanceof String) {
88              value = valueStack.findValue((String) key);
89          }
90  
91          return value;
92      }
93  }