| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||||||
| XPathReaderFactory |
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| 5.0;5 |
| 1 | /* |
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| 2 | * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/saxpath/helpers/XPathReaderFactory.java,v 1.7 2005/06/28 13:44:46 elharo Exp $ |
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| 3 | * $Revision: 1.7 $ |
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| 4 | * $Date: 2005/06/28 13:44:46 $ |
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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: XPathReaderFactory.java,v 1.7 2005/06/28 13:44:46 elharo Exp $ |
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| 60 | */ |
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| 61 | ||
| 62 | ||
| 63 | ||
| 64 | ||
| 65 | package org.jaxen.saxpath.helpers; |
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| 66 | ||
| 67 | import org.jaxen.saxpath.SAXPathException; |
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| 68 | import org.jaxen.saxpath.XPathReader; |
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| 69 | ||
| 70 | /** Create an {@link org.jaxen.saxpath.XPathReader} from |
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| 71 | * either a system property, or a named class. |
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| 72 | * |
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| 73 | * <p> |
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| 74 | * Similar to the SAX API, the <code>XPathReaderFactory</code> |
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| 75 | * can create an <code>XPathReader</code> from a name of a |
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| 76 | * class passed in directly, or by inspecting the system |
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| 77 | * property <code>org.saxpath.driver</code>. |
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| 78 | * |
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| 79 | * @author bob mcwhirter (bob@werken.com) |
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| 80 | */ |
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| 81 | public class XPathReaderFactory |
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| 82 | { |
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| 83 | /** The <code>org.saxpath.driver</code> property name. */ |
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| 84 | public static final String DRIVER_PROPERTY = "org.saxpath.driver"; |
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| 85 | ||
| 86 | /** The default driver to use if none is configured. */ |
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| 87 | protected static final String DEFAULT_DRIVER = "org.jaxen.saxpath.base.XPathReader"; |
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| 88 | ||
| 89 | 0 | private XPathReaderFactory() {} |
| 90 | ||
| 91 | ||
| 92 | /** Create an <code>XPathReader</code> using the value of |
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| 93 | * the <code>org.saxpath.driver</code> system property. |
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| 94 | * |
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| 95 | * @return an instance of the <code>XPathReader</code> specified |
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| 96 | * by the <code>org.saxpath.driver</code> property |
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| 97 | * |
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| 98 | * @throws SAXPathException if the property is not set, or if |
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| 99 | * the class can not be instantiated for some reason, |
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| 100 | * or if the class doesn't implement the <code>XPathReader</code> |
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| 101 | * interface |
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| 102 | */ |
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| 103 | public static XPathReader createReader() throws SAXPathException |
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| 104 | { |
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| 105 | 10752 | String className = null; |
| 106 | ||
| 107 | try |
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| 108 | { |
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| 109 | 10752 | className = System.getProperty( DRIVER_PROPERTY ); |
| 110 | } |
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| 111 | 0 | catch (SecurityException e) |
| 112 | { |
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| 113 | // we'll use the default |
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| 114 | 10752 | } |
| 115 | ||
| 116 | 10752 | if ( className == null |
| 117 | || |
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| 118 | className.length() == 0 ) |
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| 119 | { |
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| 120 | 10728 | className = DEFAULT_DRIVER; |
| 121 | } |
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| 122 | ||
| 123 | 10752 | return createReader( className ); |
| 124 | } |
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| 125 | ||
| 126 | /** Create an <code>XPathReader</code> using the passed |
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| 127 | * in class name. |
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| 128 | * |
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| 129 | * @param className the name of the class that implements |
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| 130 | * the <code>XPathReader</code> interface. |
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| 131 | * |
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| 132 | * @return an XPathReader |
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| 133 | * |
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| 134 | * @throws SAXPathException if the class cannot be |
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| 135 | * instantiated for some reason, or if the |
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| 136 | * class doesn't implement the <code>XPathReader</code> |
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| 137 | * interface |
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| 138 | */ |
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| 139 | public static XPathReader createReader(String className) throws SAXPathException |
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| 140 | { |
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| 141 | 10770 | Class readerClass = null; |
| 142 | 10770 | XPathReader reader = null; |
| 143 | ||
| 144 | try |
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| 145 | { |
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| 146 | // Use the full version of Class.forName(), so as to |
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| 147 | // work better in sandboxed environments, such as |
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| 148 | // servlet containers and applets. |
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| 149 | ||
| 150 | 10770 | readerClass = Class.forName( className, |
| 151 | true, |
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| 152 | 636 | XPathReaderFactory.class.getClassLoader() ); |
| 153 | ||
| 154 | // Double-check that it's actually the right kind of class |
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| 155 | // before attempting instantiation. |
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| 156 | ||
| 157 | 10758 | if ( ! XPathReader.class.isAssignableFrom( readerClass ) ) |
| 158 | { |
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| 159 | 18 | throw new SAXPathException( "Class [" + className |
| 160 | + "] does not implement the org.jaxen.saxpath.XPathReader interface." ); |
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| 161 | } |
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| 162 | } |
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| 163 | 12 | catch (ClassNotFoundException e) |
| 164 | { |
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| 165 | 12 | throw new SAXPathException( e ); |
| 166 | 10740 | } |
| 167 | ||
| 168 | try |
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| 169 | { |
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| 170 | 10740 | reader = (XPathReader) readerClass.newInstance(); |
| 171 | } |
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| 172 | 0 | catch (IllegalAccessException e) |
| 173 | { |
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| 174 | 0 | throw new SAXPathException( e ); |
| 175 | } |
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| 176 | 0 | catch (InstantiationException e) |
| 177 | { |
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| 178 | 0 | throw new SAXPathException( e ); |
| 179 | 10740 | } |
| 180 | ||
| 181 | 10740 | if ( reader == null ) |
| 182 | { |
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| 183 | 0 | throw new SAXPathException( "Unable to create XPathReader" ); |
| 184 | } |
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| 185 | ||
| 186 | 10740 | return reader; |
| 187 | } |
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| 188 | } |