KickJava   Java API By Example, From Geeks To Geeks.

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


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
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  * Addition : either integer addition or string concatenation.
24  *
25  * @author <a HREF="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
26  * @version $Id: ASTAddNode.java 398180 2006-04-29 15:40:35Z dion $
27  */
28 public class ASTAddNode extends SimpleNode {
29     /**
30      * Create the node given an id.
31      *
32      * @param id node id.
33      */
34     public ASTAddNode(int id) {
35         super(id);
36     }
37
38     /**
39      * Create a node with the given parser and id.
40      *
41      * @param p a parser.
42      * @param id node id.
43      */
44     public ASTAddNode(Parser p, int id) {
45         super(p, id);
46     }
47
48
49     /**
50      * {@inheritDoc}
51      */
52     public Object JavaDoc jjtAccept(ParserVisitor visitor, Object JavaDoc data) {
53         return visitor.visit(this, data);
54     }
55
56     /**
57      * {@inheritDoc}
58      */
59     public Object JavaDoc value(JexlContext context) throws Exception JavaDoc {
60         Object JavaDoc left = ((SimpleNode) jjtGetChild(0)).value(context);
61         Object JavaDoc right = ((SimpleNode) jjtGetChild(1)).value(context);
62
63         /*
64          * the spec says 'and'
65          */
66         if (left == null && right == null) {
67             return new Long JavaDoc(0);
68         }
69
70         /*
71          * if anything is float, double or string with ( "." | "E" | "e")
72          * coerce all to doubles and do it
73          */
74         if (left instanceof Float JavaDoc || left instanceof Double JavaDoc
75             || right instanceof Float JavaDoc || right instanceof Double JavaDoc
76             || (left instanceof String JavaDoc
77                   && (((String JavaDoc) left).indexOf(".") != -1
78                           || ((String JavaDoc) left).indexOf("e") != -1
79                           || ((String JavaDoc) left).indexOf("E") != -1)
80                )
81             || (right instanceof String JavaDoc
82                   && (((String JavaDoc) right).indexOf(".") != -1
83                           || ((String JavaDoc) right).indexOf("e") != -1
84                           || ((String JavaDoc) right).indexOf("E") != -1)
85                )
86             ) {
87
88             /*
89              * in the event that either is null and not both, then just make the
90              * null a 0
91              */
92
93             try {
94                 Double JavaDoc l = Coercion.coerceDouble(left);
95                 Double JavaDoc r = Coercion.coerceDouble(right);
96                 return new Double JavaDoc(l.doubleValue() + r.doubleValue());
97             } catch (java.lang.NumberFormatException JavaDoc nfe) {
98                 /*
99                  * Well, use strings!
100                  */
101                 return left.toString().concat(right.toString());
102             }
103         }
104
105         /*
106          * attempt to use Longs
107          */
108         try {
109             Long JavaDoc l = Coercion.coerceLong(left);
110             Long JavaDoc r = Coercion.coerceLong(right);
111             return new Long JavaDoc(l.longValue() + r.longValue());
112         } catch (java.lang.NumberFormatException JavaDoc nfe) {
113             /*
114              * Well, use strings!
115              */
116             return left.toString().concat(right.toString());
117         }
118     }
119 }
120
Popular Tags