Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||||||
SumFunction |
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| 3.0;3 |
1 | /* |
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2 | * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/SumFunction.java,v 1.10 2005/06/28 13:44:45 elharo Exp $ |
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3 | * $Revision: 1.10 $ |
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4 | * $Date: 2005/06/28 13:44:45 $ |
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5 | * |
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6 | * ==================================================================== |
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7 | * |
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8 | * Copyright (C) 2000-2002 bob mcwhirter & James Strachan. |
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9 | * All rights reserved. |
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10 | * |
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11 | * Redistribution and use in source and binary forms, with or without |
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12 | * modification, are permitted provided that the following conditions |
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13 | * are met: |
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14 | * |
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15 | * 1. Redistributions of source code must retain the above copyright |
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16 | * notice, this list of conditions, and the following disclaimer. |
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17 | * |
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18 | * 2. Redistributions in binary form must reproduce the above copyright |
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19 | * notice, this list of conditions, and the disclaimer that follows |
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20 | * these conditions in the documentation and/or other materials |
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21 | * provided with the distribution. |
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22 | * |
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23 | * 3. The name "Jaxen" must not be used to endorse or promote products |
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24 | * derived from this software without prior written permission. For |
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25 | * written permission, please contact license@jaxen.org. |
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26 | * |
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27 | * 4. Products derived from this software may not be called "Jaxen", nor |
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28 | * may "Jaxen" appear in their name, without prior written permission |
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29 | * from the Jaxen Project Management (pm@jaxen.org). |
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30 | * |
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31 | * In addition, we request (but do not require) that you include in the |
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32 | * end-user documentation provided with the redistribution and/or in the |
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33 | * software itself an acknowledgement equivalent to the following: |
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34 | * "This product includes software developed by the |
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35 | * Jaxen Project <http://www.jaxen.org/>." |
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36 | * Alternatively, the acknowledgment may be graphical using the logos |
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37 | * available at http://www.jaxen.org/ |
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38 | * |
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39 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
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40 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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41 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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42 | * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT |
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43 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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44 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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45 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
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46 | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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47 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
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48 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
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49 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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50 | * SUCH DAMAGE. |
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51 | * |
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52 | * ==================================================================== |
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53 | * This software consists of voluntary contributions made by many |
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54 | * individuals on behalf of the Jaxen Project and was originally |
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55 | * created by bob mcwhirter <bob@werken.com> and |
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56 | * James Strachan <jstrachan@apache.org>. For more information on the |
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57 | * Jaxen Project, please see <http://www.jaxen.org/>. |
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58 | * |
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59 | * $Id: SumFunction.java,v 1.10 2005/06/28 13:44:45 elharo Exp $ |
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60 | */ |
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61 | ||
62 | ||
63 | package org.jaxen.function; |
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64 | ||
65 | import java.util.Iterator; |
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66 | import java.util.List; |
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67 | ||
68 | import org.jaxen.Context; |
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69 | import org.jaxen.Function; |
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70 | import org.jaxen.FunctionCallException; |
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71 | import org.jaxen.Navigator; |
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72 | ||
73 | /** |
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74 | * <p><b>4.4</b> <code><i>number</i> sum(<i>node-set</i>)</code> </p> |
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75 | * |
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76 | * <blockquote src="http://www.w3.org/TR/xpath#function-sum"> |
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77 | * The sum function returns the sum, for each node in the argument node-set, |
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78 | * of the result of converting the string-values of the node to a number. |
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79 | * </blockquote> |
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80 | * |
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81 | * @author bob mcwhirter (bob @ werken.com) |
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82 | * @see <a href="http://www.w3.org/TR/xpath#function-sum" target="_top">Section 4.4 of the XPath Specification</a> |
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83 | */ |
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84 | public class SumFunction implements Function |
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85 | { |
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86 | ||
87 | /** |
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88 | * Create a new <code>SumFunction</code> object. |
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89 | */ |
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90 | 294 | public SumFunction() {} |
91 | ||
92 | /** Returns the sum of its arguments. |
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93 | * |
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94 | * @param context the context at the point in the |
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95 | * expression when the function is called |
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96 | * @param args a list that contains exactly one item, also a <code>List</code> |
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97 | * |
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98 | * @return a <code>Double</code> containing the sum of the items in <code>args.get(0)</code> |
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99 | * |
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100 | * @throws FunctionCallException if <code>args</code> has more or less than one item; |
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101 | * or if the first argument is not a <code>List</code> |
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102 | */ |
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103 | public Object call(Context context, |
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104 | List args) throws FunctionCallException |
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105 | { |
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106 | ||
107 | 60 | if (args.size() == 1) |
108 | { |
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109 | 54 | return evaluate( args.get(0), |
110 | context.getNavigator() ); |
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111 | } |
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112 | ||
113 | 6 | throw new FunctionCallException( "sum() requires one argument." ); |
114 | } |
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115 | ||
116 | /** |
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117 | * Returns the sum of the items in a list. |
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118 | * If necessary, each item in the list is first converted to a <code>Double</code> |
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119 | * as if by the XPath <code>number()</code> function. |
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120 | * |
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121 | * @param obj a <code>List</code> of numbers to be summed |
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122 | * @param nav ignored |
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123 | * |
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124 | * @return the sum of the list |
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125 | * |
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126 | * @throws FunctionCallException if <code>obj</code> is not a <code>List</code> |
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127 | */ |
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128 | public static Double evaluate(Object obj, |
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129 | Navigator nav) throws FunctionCallException |
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130 | { |
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131 | 54 | double sum = 0; |
132 | ||
133 | 54 | if (obj instanceof List) |
134 | { |
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135 | 48 | Iterator nodeIter = ((List)obj).iterator(); |
136 | 1296 | while ( nodeIter.hasNext() ) |
137 | { |
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138 | 1248 | double term = NumberFunction.evaluate( nodeIter.next(), |
139 | nav ).doubleValue(); |
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140 | 1248 | sum += term; |
141 | } |
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142 | } |
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143 | else |
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144 | { |
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145 | 6 | throw new FunctionCallException("The argument to the sum function must be a node-set"); |
146 | } |
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147 | ||
148 | 48 | return new Double(sum); |
149 | } |
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150 | ||
151 | } |