Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
CountFunction |
|
| 3.0;3 |
1 | /* | |
2 | * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/CountFunction.java,v 1.14 2006/02/05 21:47:41 elharo Exp $ | |
3 | * $Revision: 1.14 $ | |
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: CountFunction.java,v 1.14 2006/02/05 21:47:41 elharo Exp $ | |
46 | */ | |
47 | ||
48 | package org.jaxen.function; | |
49 | ||
50 | import java.util.List; | |
51 | ||
52 | import org.jaxen.Context; | |
53 | import org.jaxen.Function; | |
54 | import org.jaxen.FunctionCallException; | |
55 | ||
56 | /** | |
57 | * <p><b>4.1</b> <code><i>number</i> count(<i>node-set</i>)</code></p> | |
58 | * | |
59 | * <blockquote src="http://www.w3.org/TR/xpath#function-count"> | |
60 | * The <b>count</b> function returns the number of nodes in the argument node-set. | |
61 | * </blockquote> | |
62 | * @author bob mcwhirter (bob @ werken.com) | |
63 | * @see <a href="http://www.w3.org/TR/xpath#function-count">Section 4.1 of the XPath Specification</a> | |
64 | */ | |
65 | public class CountFunction implements Function | |
66 | { | |
67 | ||
68 | /** | |
69 | * Create a new <code>CountFunction</code> object. | |
70 | */ | |
71 | 106 | public CountFunction() {} |
72 | ||
73 | /** | |
74 | * <p> | |
75 | * Returns the number of nodes in the specified node-set. | |
76 | * </p> | |
77 | * @param context ignored | |
78 | * @param args the function arguments | |
79 | * | |
80 | * @return a <code>Double</code> giving the integral number of items in the first argument | |
81 | * | |
82 | * @throws FunctionCallException if args does not have exactly one | |
83 | * item; or that item is not a <code>List</code> | |
84 | */ | |
85 | public Object call(Context context, | |
86 | List args) throws FunctionCallException | |
87 | { | |
88 | 536 | if (args.size() == 1) |
89 | { | |
90 | 532 | return evaluate( args.get(0) ); |
91 | } | |
92 | ||
93 | 4 | throw new FunctionCallException( "count() requires one argument." ); |
94 | } | |
95 | ||
96 | /** | |
97 | * <p> | |
98 | * Returns the number of nodes in the specified node-set. | |
99 | * </p> | |
100 | * | |
101 | * @param obj a <code>List</code> of nodes | |
102 | * @return the integral number of items in the list | |
103 | * @throws FunctionCallException if obj is not a <code>List</code> | |
104 | */ | |
105 | public static Double evaluate(Object obj) throws FunctionCallException | |
106 | { | |
107 | ||
108 | 532 | if (obj instanceof List) |
109 | { | |
110 | 530 | return new Double( ((List) obj).size() ); |
111 | } | |
112 | ||
113 | 2 | throw new FunctionCallException("count() function can only be used for node-sets"); |
114 | ||
115 | } | |
116 | ||
117 | } |