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1   /*
2    * Copyright 2002,2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.commons.jexl.parser;
17  
18  import org.apache.commons.jexl.JexlContext;
19  import org.apache.commons.jexl.util.Coercion;
20  
21  /***
22   *  LE : a <= b
23   *
24   *  Follows A.3.6.1 of the JSTL 1.0 specification
25   *
26   *  @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
27   *  @author <a href="mailto:proyal@apache.org">Peter Royal</a>
28   *  @version $Id: ASTLENode.java,v 1.4 2004/02/28 13:45:20 yoavs Exp $
29   */
30  public class ASTLENode extends SimpleNode
31  {
32      public ASTLENode(int id)
33      {
34          super(id);
35      }
36  
37      public ASTLENode(Parser p, int id)
38      {
39          super(p, id);
40      }
41  
42      /*** Accept the visitor. **/
43      public Object jjtAccept(ParserVisitor visitor, Object data)
44      {
45          return visitor.visit(this, data);
46      }
47  
48      public Object value(JexlContext jc)
49          throws Exception
50      {
51          /*
52           * now get the values
53           */
54  
55          Object left = ( (SimpleNode) jjtGetChild(0)).value(jc);
56          Object right = ( (SimpleNode) jjtGetChild(1)).value(jc);
57  
58          if( left == right )
59          {
60              return Boolean.TRUE;
61          }
62          else if ( ( left == null ) || ( right == null ) )
63          {
64              return Boolean.FALSE;
65          }
66          else if( Coercion.isFloatingPoint( left ) || Coercion.isFloatingPoint( right ) )
67          {
68              double leftDouble = Coercion.coerceDouble( left ).doubleValue();
69              double rightDouble = Coercion.coerceDouble( right ).doubleValue();
70  
71              return leftDouble <= rightDouble
72                  ? Boolean.TRUE
73                  : Boolean.FALSE;
74          }
75          else if( Coercion.isNumberable( left ) || Coercion.isNumberable( right ) )
76          {
77              long leftLong = Coercion.coerceLong( left ).longValue();
78              long rightLong = Coercion.coerceLong( right ).longValue();
79  
80              return leftLong <= rightLong
81                  ? Boolean.TRUE
82                  : Boolean.FALSE;
83          }
84          else if( left instanceof String || right instanceof String )
85          {
86              String leftString = left.toString();
87              String rightString = right.toString();
88  
89              return leftString.compareTo( rightString ) <= 0
90                  ? Boolean.TRUE
91                  : Boolean.FALSE;
92          }
93          else if( left instanceof Comparable )
94          {
95              return ( (Comparable)left ).compareTo( right ) <= 0
96                  ? Boolean.TRUE
97                  : Boolean.FALSE;
98          }
99          else if( right instanceof Comparable )
100         {
101             return ( (Comparable)right ).compareTo( left ) >= 0
102                 ? Boolean.TRUE
103                 : Boolean.FALSE;
104         }
105 
106         throw new Exception("Invalid comparison : LE ");
107     }
108 
109 }