Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
SumFunction |
|
| 3.0;3 |
1 | /* | |
2 | * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/SumFunction.java,v 1.11 2006/02/05 21:47:41 elharo Exp $ | |
3 | * $Revision: 1.11 $ | |
4 | * $Date: 2006/02/05 21:47:41 $ | |
5 | * | |
6 | * ==================================================================== | |
7 | * | |
8 | * Copyright 2000-2002 bob mcwhirter & James Strachan. | |
9 | * All rights reserved. | |
10 | * | |
11 | * Redistribution and use in source and binary forms, with or without | |
12 | * modification, are permitted provided that the following conditions are | |
13 | * met: | |
14 | * | |
15 | * * Redistributions of source code must retain the above copyright | |
16 | * notice, this list of conditions and the following disclaimer. | |
17 | * | |
18 | * * Redistributions in binary form must reproduce the above copyright | |
19 | * notice, this list of conditions and the following disclaimer in the | |
20 | * documentation and/or other materials provided with the distribution. | |
21 | * | |
22 | * * Neither the name of the Jaxen Project nor the names of its | |
23 | * contributors may be used to endorse or promote products derived | |
24 | * from this software without specific prior written permission. | |
25 | * | |
26 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS | |
27 | * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED | |
28 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A | |
29 | * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER | |
30 | * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | |
31 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |
32 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | |
33 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | |
34 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | |
35 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | |
36 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
37 | * | |
38 | * ==================================================================== | |
39 | * This software consists of voluntary contributions made by many | |
40 | * individuals on behalf of the Jaxen Project and was originally | |
41 | * created by bob mcwhirter <bob@werken.com> and | |
42 | * James Strachan <jstrachan@apache.org>. For more information on the | |
43 | * Jaxen Project, please see <http://www.jaxen.org/>. | |
44 | * | |
45 | * $Id: SumFunction.java,v 1.11 2006/02/05 21:47:41 elharo Exp $ | |
46 | */ | |
47 | ||
48 | ||
49 | package org.jaxen.function; | |
50 | ||
51 | import java.util.Iterator; | |
52 | import java.util.List; | |
53 | ||
54 | import org.jaxen.Context; | |
55 | import org.jaxen.Function; | |
56 | import org.jaxen.FunctionCallException; | |
57 | import org.jaxen.Navigator; | |
58 | ||
59 | /** | |
60 | * <p><b>4.4</b> <code><i>number</i> sum(<i>node-set</i>)</code> </p> | |
61 | * | |
62 | * <blockquote src="http://www.w3.org/TR/xpath#function-sum"> | |
63 | * The sum function returns the sum, for each node in the argument node-set, | |
64 | * of the result of converting the string-values of the node to a number. | |
65 | * </blockquote> | |
66 | * | |
67 | * @author bob mcwhirter (bob @ werken.com) | |
68 | * @see <a href="http://www.w3.org/TR/xpath#function-sum" target="_top">Section 4.4 of the XPath Specification</a> | |
69 | */ | |
70 | public class SumFunction implements Function | |
71 | { | |
72 | ||
73 | /** | |
74 | * Create a new <code>SumFunction</code> object. | |
75 | */ | |
76 | 106 | public SumFunction() {} |
77 | ||
78 | /** Returns the sum of its arguments. | |
79 | * | |
80 | * @param context the context at the point in the | |
81 | * expression when the function is called | |
82 | * @param args a list that contains exactly one item, also a <code>List</code> | |
83 | * | |
84 | * @return a <code>Double</code> containing the sum of the items in <code>args.get(0)</code> | |
85 | * | |
86 | * @throws FunctionCallException if <code>args</code> has more or less than one item; | |
87 | * or if the first argument is not a <code>List</code> | |
88 | */ | |
89 | public Object call(Context context, | |
90 | List args) throws FunctionCallException | |
91 | { | |
92 | ||
93 | 20 | if (args.size() == 1) |
94 | { | |
95 | 18 | return evaluate( args.get(0), |
96 | context.getNavigator() ); | |
97 | } | |
98 | ||
99 | 2 | throw new FunctionCallException( "sum() requires one argument." ); |
100 | } | |
101 | ||
102 | /** | |
103 | * Returns the sum of the items in a list. | |
104 | * If necessary, each item in the list is first converted to a <code>Double</code> | |
105 | * as if by the XPath <code>number()</code> function. | |
106 | * | |
107 | * @param obj a <code>List</code> of numbers to be summed | |
108 | * @param nav ignored | |
109 | * | |
110 | * @return the sum of the list | |
111 | * | |
112 | * @throws FunctionCallException if <code>obj</code> is not a <code>List</code> | |
113 | */ | |
114 | public static Double evaluate(Object obj, | |
115 | Navigator nav) throws FunctionCallException | |
116 | { | |
117 | 18 | double sum = 0; |
118 | ||
119 | 18 | if (obj instanceof List) |
120 | { | |
121 | 16 | Iterator nodeIter = ((List)obj).iterator(); |
122 | 432 | while ( nodeIter.hasNext() ) |
123 | { | |
124 | 416 | double term = NumberFunction.evaluate( nodeIter.next(), |
125 | nav ).doubleValue(); | |
126 | 416 | sum += term; |
127 | 416 | } |
128 | 16 | } |
129 | else | |
130 | { | |
131 | 2 | throw new FunctionCallException("The argument to the sum function must be a node-set"); |
132 | } | |
133 | ||
134 | 16 | return new Double(sum); |
135 | } | |
136 | ||
137 | } |