View Javadoc

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.jexl.parser;
18  
19  import org.apache.commons.jexl.JexlContext;
20  import org.apache.commons.jexl.util.Coercion;
21  
22  /**
23   * Not : 'not' or '!'.
24   * 
25   * @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
26   * @version $Id: ASTNotNode.java 480412 2006-11-29 05:11:23Z bayard $
27   */
28  
29  public class ASTNotNode extends SimpleNode {
30      /**
31       * Create the node given an id.
32       * 
33       * @param id node id.
34       */
35      public ASTNotNode(int id) {
36          super(id);
37      }
38  
39      /**
40       * Create a node with the given parser and id.
41       * 
42       * @param p a parser.
43       * @param id node id.
44       */
45      public ASTNotNode(Parser p, int id) {
46          super(p, id);
47      }
48  
49      /** {@inheritDoc} */
50      public Object jjtAccept(ParserVisitor visitor, Object data) {
51          return visitor.visit(this, data);
52      }
53  
54      /** {@inheritDoc} */
55      public Object value(JexlContext jc) throws Exception {
56          Object val = ((SimpleNode) jjtGetChild(0)).value(jc);
57  
58          /*
59           * coercion rules
60           */
61  
62          Boolean b = Coercion.coerceBoolean(val);
63  
64          if (b != null) {
65              return b.booleanValue() ? Boolean.FALSE : Boolean.TRUE;
66          }
67  
68          throw new Exception("expression not boolean valued");
69      }
70  
71  }