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1   /*
2    * Copyright 1999-2004 The Apache Software Foundation
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.jxpath.servlet;
17  
18  import org.apache.commons.jxpath.Variables;
19  
20  /***
21   * Implementation of the Variables interface that provides access
22   * to a single object using a reserved name (keyword).
23   *
24   * @author Dmitri Plotnikov
25   * @version $Revision: 1.6 $ $Date: 2004/02/29 14:17:40 $
26   */
27  public class KeywordVariables implements Variables {
28  
29      private String keyword;
30      private Object object;
31  
32      public KeywordVariables(String keyword, Object object) {
33          this.keyword = keyword;
34          this.object = object;
35      }
36  
37      public boolean isDeclaredVariable(String variable) {
38          return variable.equals(keyword);
39      }
40  
41      public Object getVariable(String variable) {
42          if (variable.equals(keyword)) {
43              return object;
44          }
45          return null;
46      }
47  
48      public void declareVariable(String variable, Object value) {
49          throw new UnsupportedOperationException(
50              "Cannot declare new keyword variables.");
51      }
52  
53      public void undeclareVariable(String variable) {
54          throw new UnsupportedOperationException(
55              "Cannot declare new keyword variables.");
56      }
57  }