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 and 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 AndOperator
30 extends BinaryOperator
31 {
32 //-------------------------------------
33 // Singleton
34 //-------------------------------------
35
36 public static final AndOperator SINGLETON =
37 new AndOperator ();
38
39 //-------------------------------------
40 /**
41 *
42 * Constructor
43 **/
44 public AndOperator ()
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 "and";
58 }
59
60 //-------------------------------------
61 /**
62 *
63 * Applies the operator to the given value
64 **/
65 public Object apply (Object pLeft,
66 Object pRight)
67 throws ELException
68 {
69 // Coerce the values to booleans
70 boolean left =
71 Coercions.coerceToBoolean (pLeft).booleanValue ();
72 boolean right =
73 Coercions.coerceToBoolean (pRight).booleanValue ();
74
75 return PrimitiveObjects.getBoolean (left && right);
76 }
77
78 //-------------------------------------
79 /**
80 *
81 * Returns true if evaluation is necessary given the specified Left
82 * value. The And/OrOperators make use of this
83 **/
84 public boolean shouldEvaluate (Object pLeft)
85 {
86 return
87 (pLeft instanceof Boolean) &&
88 ((Boolean) pLeft).booleanValue () == true;
89 }
90
91 //-------------------------------------
92 /**
93 *
94 * Returns true if the operator expects its arguments to be coerced
95 * to Booleans. The And/Or operators set this to true.
96 **/
97 public boolean shouldCoerceToBoolean ()
98 {
99 return true;
100 }
101
102 //-------------------------------------
103 }