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 not 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 NotOperator
30 extends UnaryOperator
31 {
32 //-------------------------------------
33 // Singleton
34 //-------------------------------------
35
36 public static final NotOperator SINGLETON =
37 new NotOperator ();
38
39 //-------------------------------------
40 /**
41 *
42 * Constructor
43 **/
44 public NotOperator ()
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 "not";
58 }
59
60 //-------------------------------------
61 /**
62 *
63 * Applies the operator to the given value
64 **/
65 public Object apply (Object pValue)
66 throws ELException
67 {
68 // Coerce the value to a boolean
69 boolean val = Coercions.coerceToBoolean (pValue).booleanValue ();
70
71 return PrimitiveObjects.getBoolean (!val);
72 }
73
74 //-------------------------------------
75 }