Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||||||
StringFunction |
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| 8.8;8.8 |
1 | /* |
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2 | * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/StringFunction.java,v 1.30 2005/09/14 13:03:59 elharo Exp $ |
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3 | * $Revision: 1.30 $ |
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4 | * $Date: 2005/09/14 13:03:59 $ |
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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: StringFunction.java,v 1.30 2005/09/14 13:03:59 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 org.jaxen.Context; |
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66 | import org.jaxen.Function; |
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67 | import org.jaxen.FunctionCallException; |
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68 | import org.jaxen.Navigator; |
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69 | import org.jaxen.UnsupportedAxisException; |
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70 | import org.jaxen.JaxenRuntimeException; |
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71 | ||
72 | import java.text.DecimalFormat; |
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73 | import java.text.NumberFormat; |
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74 | import java.text.DecimalFormatSymbols; |
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75 | import java.util.List; |
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76 | import java.util.Iterator; |
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77 | import java.util.Locale; |
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78 | ||
79 | /** |
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80 | * <p> |
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81 | * <b>4.2</b> <code><i>string</i> string(<i>object</i>)</code> |
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82 | * </p> |
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83 | * |
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84 | * |
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85 | * <blockquote src="http://www.w3.org/TR/xpath"> |
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86 | * <p> |
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87 | * The <b>string</b> function converts |
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88 | * an object to a string as follows: |
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89 | * </p> |
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90 | * |
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91 | * <ul> |
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92 | * |
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93 | * <li> |
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94 | * <p> |
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95 | * A node-set is converted to a string by returning the <a |
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96 | * href="http://www.w3.org/TR/xpath#dt-string-value" target="_top">string-value</a> of the node in the node-set |
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97 | * that is first in <a href="http://www.w3.org/TR/xpath#dt-document-order" target="_top">document order</a>. If |
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98 | * the node-set is empty, an empty string is returned. |
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99 | * </p> |
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100 | * </li> |
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101 | * |
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102 | * <li> |
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103 | * <p> |
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104 | * A number is converted to a string as follows |
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105 | * </p> |
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106 | * |
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107 | * <ul> |
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108 | * |
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109 | * <li> |
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110 | * <p> |
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111 | * NaN is converted to the string <code>NaN</code> |
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112 | * </p> |
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113 | * </li> |
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114 | * |
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115 | * <li> |
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116 | * <p> |
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117 | * positive zero is converted to the string <code>0</code> |
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118 | * </p> |
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119 | * </li> |
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120 | * |
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121 | * <li> |
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122 | * |
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123 | * <p> |
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124 | * negative zero is converted to the string <code>0</code> |
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125 | * </p> |
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126 | * </li> |
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127 | * |
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128 | * <li> |
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129 | * <p> |
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130 | * positive infinity is converted to the string <code>Infinity</code> |
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131 | * </p> |
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132 | * </li> |
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133 | * |
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134 | * <li> |
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135 | * <p> |
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136 | * negative infinity is converted to the string <code>-Infinity</code> |
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137 | * |
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138 | * </p> |
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139 | * </li> |
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140 | * |
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141 | * <li> |
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142 | * <p> |
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143 | * if the number is an integer, the number is represented in decimal |
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144 | * form as a <a href="http://www.w3.org/TR/xpath#NT-Number" target="_top">Number</a> with no decimal point and |
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145 | * no leading zeros, preceded by a minus sign (<code>-</code>) if |
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146 | * the number is negative |
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147 | * </p> |
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148 | * </li> |
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149 | * |
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150 | * <li> |
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151 | * <p> |
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152 | * otherwise, the number is represented in decimal form as a Number including a decimal point with at least |
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153 | * one digit before the decimal point and at least one digit after the |
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154 | * decimal point, preceded by a minus sign (<code>-</code>) if the |
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155 | * number is negative; there must be no leading zeros before the decimal |
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156 | * point apart possibly from the one required digit immediately before |
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157 | * the decimal point; beyond the one required digit after the decimal |
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158 | * point there must be as many, but only as many, more digits as are |
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159 | * needed to uniquely distinguish the number from all other IEEE 754 |
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160 | * numeric values. |
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161 | * </p> |
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162 | * |
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163 | * </li> |
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164 | * |
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165 | * </ul> |
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166 | * |
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167 | * </li> |
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168 | * |
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169 | * <li> |
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170 | * <p> |
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171 | * The boolean false value is converted to the string <code>false</code>. |
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172 | * The boolean true value is converted to the string <code>true</code>. |
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173 | * </p> |
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174 | * </li> |
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175 | * |
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176 | * <li> |
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177 | * <p> |
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178 | * An object of a type other than the four basic types is converted to a |
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179 | * string in a way that is dependent on that type. |
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180 | * </p> |
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181 | * |
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182 | * </li> |
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183 | * |
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184 | * </ul> |
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185 | * |
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186 | * <p> |
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187 | * If the argument is omitted, it defaults to a node-set with the |
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188 | * context node as its only member. |
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189 | * </p> |
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190 | * |
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191 | * </blockquote> |
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192 | * |
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193 | * @author bob mcwhirter (bob @ werken.com) |
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194 | * @see <a href="http://www.w3.org/TR/xpath#function-string" |
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195 | * target="_top">Section 4.2 of the XPath Specification</a> |
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196 | */ |
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197 | public class StringFunction implements Function |
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198 | { |
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199 | ||
200 | 487 | private static DecimalFormat format = (DecimalFormat) NumberFormat.getInstance(Locale.ENGLISH); |
201 | ||
202 | static { |
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203 | 487 | DecimalFormatSymbols symbols = new DecimalFormatSymbols(Locale.ENGLISH); |
204 | 487 | symbols.setNaN("NaN"); |
205 | 487 | symbols.setInfinity("Infinity"); |
206 | 487 | format.setGroupingUsed(false); |
207 | 487 | format.setMaximumFractionDigits(32); |
208 | 487 | format.setDecimalFormatSymbols(symbols); |
209 | 487 | } |
210 | ||
211 | /** |
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212 | * Create a new <code>StringFunction</code> object. |
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213 | */ |
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214 | 497 | public StringFunction() {} |
215 | ||
216 | /** |
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217 | * Returns the string-value of |
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218 | * <code>args.get(0)</code> or of the context node if ,code>args</code> is empty. |
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219 | * |
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220 | * @param context the context at the point in the |
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221 | * expression where the function is called |
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222 | * @param args list with zero or one element |
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223 | * |
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224 | * @return a <code>String</code> |
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225 | * |
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226 | * @throws FunctionCallException if <code>args</code> has more than one item |
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227 | */ |
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228 | public Object call(Context context, |
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229 | List args) throws FunctionCallException |
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230 | { |
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231 | 310 | int size = args.size(); |
232 | ||
233 | 310 | if ( size == 0 ) |
234 | { |
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235 | 200 | return evaluate( context.getNodeSet(), |
236 | context.getNavigator() ); |
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237 | } |
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238 | 110 | else if ( size == 1 ) |
239 | { |
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240 | 100 | return evaluate( args.get(0), |
241 | context.getNavigator() ); |
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242 | } |
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243 | ||
244 | 10 | throw new FunctionCallException( "string() takes at most argument." ); |
245 | } |
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246 | ||
247 | /** |
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248 | * Returns the string-value of <code>obj</code>. |
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249 | * |
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250 | * @param obj the object whose string-value is calculated |
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251 | * @param nav the navigator used to calculate the string-value |
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252 | * |
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253 | * @return a <code>String</code>. May be empty but is never null. |
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254 | */ |
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255 | public static String evaluate(Object obj, |
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256 | Navigator nav) |
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257 | { |
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258 | try |
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259 | { |
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260 | 56486 | if (obj == null) { |
261 | 0 | return ""; |
262 | } |
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263 | ||
264 | // Workaround because XOM uses lists for Text nodes |
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265 | // so we need to check for that first |
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266 | 56486 | if (nav != null && nav.isText(obj)) |
267 | { |
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268 | 240 | return nav.getTextStringValue(obj); |
269 | } |
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270 | ||
271 | 56246 | if (obj instanceof List) |
272 | { |
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273 | 2650 | List list = (List) obj; |
274 | 2650 | if (list.isEmpty()) |
275 | { |
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276 | 80 | return ""; |
277 | } |
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278 | // do not recurse: only first list should unwrap |
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279 | 2570 | obj = list.get(0); |
280 | } |
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281 | ||
282 | 56166 | if (nav != null) { |
283 | // This stack of instanceof really suggests there's |
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284 | // a failure to take advantage of polymorphism here |
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285 | 56166 | if (nav.isElement(obj)) |
286 | { |
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287 | 5240 | return nav.getElementStringValue(obj); |
288 | } |
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289 | 50926 | else if (nav.isAttribute(obj)) |
290 | { |
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291 | 10300 | return nav.getAttributeStringValue(obj); |
292 | } |
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293 | ||
294 | 40626 | else if (nav.isDocument(obj)) |
295 | { |
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296 | 80 | Iterator childAxisIterator = nav.getChildAxisIterator(obj); |
297 | 80 | while (childAxisIterator.hasNext()) |
298 | { |
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299 | 80 | Object descendant = childAxisIterator.next(); |
300 | 80 | if (nav.isElement(descendant)) |
301 | { |
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302 | 80 | return nav.getElementStringValue(descendant); |
303 | } |
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304 | } |
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305 | } |
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306 | 40546 | else if (nav.isProcessingInstruction(obj)) |
307 | { |
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308 | 120 | return nav.getProcessingInstructionData(obj); |
309 | } |
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310 | 40426 | else if (nav.isComment(obj)) |
311 | { |
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312 | 10 | return nav.getCommentStringValue(obj); |
313 | } |
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314 | 40416 | else if (nav.isText(obj)) |
315 | { |
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316 | 200 | return nav.getTextStringValue(obj); |
317 | } |
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318 | 40216 | else if (nav.isNamespace(obj)) |
319 | { |
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320 | 10 | return nav.getNamespaceStringValue(obj); |
321 | } |
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322 | } |
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323 | ||
324 | 40206 | if (obj instanceof String) |
325 | { |
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326 | 37680 | return (String) obj; |
327 | } |
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328 | 2526 | else if (obj instanceof Boolean) |
329 | { |
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330 | 1360 | return stringValue(((Boolean) obj).booleanValue()); |
331 | } |
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332 | 1166 | else if (obj instanceof Number) |
333 | { |
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334 | 1166 | return stringValue(((Number) obj).doubleValue()); |
335 | } |
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336 | ||
337 | } |
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338 | 0 | catch (UnsupportedAxisException e) |
339 | { |
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340 | 0 | throw new JaxenRuntimeException(e); |
341 | 0 | } |
342 | ||
343 | 0 | return ""; |
344 | ||
345 | } |
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346 | ||
347 | private static String stringValue(double value) |
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348 | { |
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349 | ||
350 | // DecimalFormat formats negative zero as "-0". |
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351 | // Therefore we need to test for zero explicitly here. |
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352 | 1166 | if (value == 0) return "0"; |
353 | ||
354 | // need to synchronize object for thread-safety |
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355 | 1084 | String result = null; |
356 | 1084 | synchronized (format) { |
357 | 1084 | result = format.format(value); |
358 | 1084 | } |
359 | 1084 | return result; |
360 | ||
361 | } |
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362 | ||
363 | private static String stringValue(boolean value) |
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364 | { |
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365 | 1360 | return value ? "true" : "false"; |
366 | } |
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367 | ||
368 | } |