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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.el;
18  
19  /**
20   *
21   * <p>An expression representing a boolean literal value
22   * 
23   * @author Nathan Abramson - Art Technology Group
24   * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: bayard $
25   **/
26  
27  public class BooleanLiteral
28    extends Literal
29  {
30    //-------------------------------------
31    // Member variables
32    //-------------------------------------
33  
34    public static final BooleanLiteral TRUE = new BooleanLiteral ("true");
35    public static final BooleanLiteral FALSE = new BooleanLiteral ("false");
36  
37    //-------------------------------------
38    /**
39     *
40     * Constructor
41     **/
42    public BooleanLiteral (String pToken)
43    {
44      super (getValueFromToken (pToken));
45    }
46  
47    //-------------------------------------
48    /**
49     *
50     * Parses the given token into the literal value
51     **/
52    static Object getValueFromToken (String pToken)
53    {
54      return
55        ("true".equals (pToken)) ?
56        Boolean.TRUE :
57        Boolean.FALSE;
58    }
59  
60    //-------------------------------------
61    // Expression methods
62    //-------------------------------------
63    /**
64     *
65     * Returns the expression in the expression language syntax
66     **/
67    public String getExpressionString ()
68    {
69      return (getValue () == Boolean.TRUE) ? "true" : "false";
70    }
71  
72    //-------------------------------------
73  }