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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  import javax.servlet.jsp.el.ELException;
20  
21  /**
22   *
23   * <p>The implementation of the or operator
24   * 
25   * @author Nathan Abramson - Art Technology Group
26   * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: bayard $
27   **/
28  
29  public class OrOperator
30    extends BinaryOperator
31  {
32    //-------------------------------------
33    // Singleton
34    //-------------------------------------
35  
36    public static final OrOperator SINGLETON =
37      new OrOperator ();
38  
39    //-------------------------------------
40    /**
41     *
42     * Constructor
43     **/
44    public OrOperator ()
45    {
46    }
47  
48    //-------------------------------------
49    // Expression methods
50    //-------------------------------------
51    /**
52     *
53     * Returns the symbol representing the operator
54     **/
55    public String getOperatorSymbol ()
56    {
57      return "or";
58    }
59  
60    //-------------------------------------
61    /**
62     *
63     * Applies the operator to the given value
64     **/
65    public Object apply (Object pLeft, Object pRight)
66      throws ELException
67    {
68      // Coerce the values to booleans
69      boolean left = 
70        Coercions.coerceToBoolean (pLeft).booleanValue ();
71      boolean right = 
72        Coercions.coerceToBoolean (pRight).booleanValue ();
73  
74      return PrimitiveObjects.getBoolean (left || right);
75    }
76  
77    //-------------------------------------
78    /**
79     *
80     * Returns true if evaluation is necessary given the specified Left
81     * value.  The And/OrOperators make use of this
82     **/
83    public boolean shouldEvaluate (Object pLeft)
84    {
85      return
86        (pLeft instanceof Boolean) &&
87        ((Boolean) pLeft).booleanValue () == false;
88    }
89  
90    //-------------------------------------
91    /**
92     *
93     * Returns true if the operator expects its arguments to be coerced
94     * to Booleans.  The And/Or operators set this to true.
95     **/
96    public boolean shouldCoerceToBoolean ()
97    {
98      return true;
99    }
100 
101   //-------------------------------------
102 }