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Java > Open Source Codes > org > apache > commons > jexl > parser > ASTGTNode


1 /*
2  * Copyright 2002-2006 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  * GT : 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: ASTGTNode.java 398197 2006-04-29 16:18:04Z dion $
29  */
30 public class ASTGTNode extends SimpleNode {
31     /**
32      * Create the node given an id.
33      *
34      * @param id node id.
35      */
36     public ASTGTNode(int id) {
37         super(id);
38     }
39
40     /**
41      * Create a node with the given parser and id.
42      *
43      * @param p a parser.
44      * @param id node id.
45      */
46     public ASTGTNode(Parser p, int id) {
47         super(p, id);
48     }
49
50     /** {@inheritDoc} */
51     public Object JavaDoc jjtAccept(ParserVisitor visitor, Object JavaDoc data) {
52         return visitor.visit(this, data);
53     }
54
55     /** {@inheritDoc} */
56     public Object JavaDoc value(JexlContext jc) throws Exception JavaDoc {
57         /*
58          * now get the values
59          */
60
61         Object JavaDoc left = ((SimpleNode) jjtGetChild(0)).value(jc);
62         Object JavaDoc right = ((SimpleNode) jjtGetChild(1)).value(jc);
63
64         if ((left == right) || (left == null) || (right == null)) {
65             return Boolean.FALSE;
66         } else if (Coercion.isFloatingPoint(left)
67                 || Coercion.isFloatingPoint(right)) {
68             double leftDouble = Coercion.coerceDouble(left).doubleValue();
69             double rightDouble = Coercion.coerceDouble(right).doubleValue();
70
71             return leftDouble > rightDouble ? Boolean.TRUE : Boolean.FALSE;
72         } else if (Coercion.isNumberable(left) || Coercion.isNumberable(right)) {
73             long leftLong = Coercion.coerceLong(left).longValue();
74             long rightLong = Coercion.coerceLong(right).longValue();
75
76             return leftLong > rightLong ? Boolean.TRUE : Boolean.FALSE;
77         } else if (left instanceof String JavaDoc || right instanceof String JavaDoc) {
78             String JavaDoc leftString = left.toString();
79             String JavaDoc rightString = right.toString();
80
81             return leftString.compareTo(rightString) > 0 ? Boolean.TRUE
82                     : Boolean.FALSE;
83         } else if (left instanceof Comparable JavaDoc) {
84             return ((Comparable JavaDoc) left).compareTo(right) > 0 ? Boolean.TRUE
85                     : Boolean.FALSE;
86         } else if (right instanceof Comparable JavaDoc) {
87             return ((Comparable JavaDoc) right).compareTo(left) < 0 ? Boolean.TRUE
88                     : Boolean.FALSE;
89         }
90
91         throw new Exception JavaDoc("Invalid comparison : GT ");
92     }
93 }
94
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