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Diffstat (limited to 'libjava/javax/xml/xpath/XPathFactory.java')
| -rw-r--r-- | libjava/javax/xml/xpath/XPathFactory.java | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/libjava/javax/xml/xpath/XPathFactory.java b/libjava/javax/xml/xpath/XPathFactory.java new file mode 100644 index 0000000..64076f5 --- /dev/null +++ b/libjava/javax/xml/xpath/XPathFactory.java @@ -0,0 +1,227 @@ +/* XPathFactory.java -- + Copyright (C) 2004 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA +02111-1307 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package javax.xml.xpath; + +import java.io.BufferedReader; +import java.io.File; +import java.io.FileInputStream; +import java.io.InputStream; +import java.io.InputStreamReader; +import java.io.IOException; +import java.util.Properties; + +/** + * Factory for creating XPath environments. + * + * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a> + * @since 1.3 + */ +public abstract class XPathFactory +{ + + /** + * The default property name according to the JAXP specification. + */ + public static final String DEFAULT_PROPERTY_NAME = + "javax.xml.xpath.XPathFactory"; + + /** + * The default object model URI. + */ + public static final String DEFAULT_OBJECT_MODEL_URI = + XPathConstants.DOM_OBJECT_MODEL; + + protected XPathFactory() + { + } + + /** + * Returns a new factory for the default (DOM) object model. + */ + public static final XPathFactory newInstance() + { + try + { + return newInstance(DEFAULT_OBJECT_MODEL_URI); + } + catch (XPathFactoryConfigurationException e) + { + throw new RuntimeException(e.getMessage()); + } + } + + /** + * Returns a new factory for the given object model URI. + * The implementation class to load is the first found in the following + * locations that advertises support for the given model URI: + * <ol> + * <li>the <code>javax.xml.xpath.XPathFactory</code> system property</li> + * <li>the above named property value in the + * <code><i>$JAVA_HOME</i>/lib/jaxp.properties</code> file</li> + * <li>the class name specified in the + * <code>META-INF/services/javax.xml.xpath.XPathFactory</code> system + * resource</li> + * <li>the default factory class</li> + * </ol> + * @param uri the object model URI + */ + public static final XPathFactory newInstance(String uri) + throws XPathFactoryConfigurationException + { + ClassLoader loader = Thread.currentThread().getContextClassLoader(); + if (loader == null) + { + loader = XPathFactory.class.getClassLoader(); + } + String className = null; + int count = 0; + do + { + className = getFactoryClassName(loader, count++); + if (className != null) + { + try + { + Class t = (loader != null) ? loader.loadClass(className) : + Class.forName(className); + XPathFactory ret = (XPathFactory) t.newInstance(); + if (ret.isObjectModelSupported(uri)) + { + return ret; + } + className = null; + } + catch (ClassNotFoundException e) + { + className = null; + } + catch (Exception e) + { + throw new XPathFactoryConfigurationException(e); + } + } + } + while (className == null && count < 4); + String msg = "no factories with support for " + uri; + throw new XPathFactoryConfigurationException(msg); + } + + private static String getFactoryClassName(ClassLoader loader, int attempt) + { + final String propertyName = DEFAULT_PROPERTY_NAME; + switch (attempt) + { + case 0: + return System.getProperty(propertyName); + case 1: + try + { + File file = new File(System.getProperty("java.home")); + file = new File(file, "lib"); + file = new File(file, "jaxp.properties"); + InputStream in = new FileInputStream(file); + Properties props = new Properties(); + props.load(in); + in.close(); + return props.getProperty(propertyName); + } + catch (IOException e) + { + return null; + } + case 2: + try + { + String serviceKey = "/META-INF/services/" + propertyName; + InputStream in = (loader != null) ? + loader.getResourceAsStream(serviceKey) : + XPathFactory.class.getResourceAsStream(serviceKey); + if (in != null) + { + BufferedReader r = + new BufferedReader(new InputStreamReader(in)); + String ret = r.readLine(); + r.close(); + return ret; + } + } + catch (IOException e) + { + } + return null; + case 3: + return "gnu.xml.xpath.XPathFactoryImpl"; + default: + return null; + } + } + + /** + * Indicates whether the specified object model URI is supported by + * this factory. + */ + public abstract boolean isObjectModelSupported(String objectModel); + + /** + * Sets the state of the named feature. + */ + public abstract void setFeature(String name, boolean value) + throws XPathFactoryConfigurationException; + + /** + * Returns the state of the named feature. + */ + public abstract boolean getFeature(String name) + throws XPathFactoryConfigurationException; + + /** + * Sets the XPath variable resolver calback. + */ + public abstract void setXPathVariableResolver(XPathVariableResolver resolver); + + /** + * Sets the XPath extension function resolver calback. + */ + public abstract void setXPathFunctionResolver(XPathFunctionResolver resolver); + + /** + * Returns a new XPath evaluation environment. + */ + public abstract XPath newXPath(); + +} |