/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.beans.factory.xml;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.w3c.dom.Document;
import org.xml.sax.EntityResolver;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.springframework.util.xml.XmlValidationModeDetector;
/**
* Spring's default {@link DocumentLoader} implementation.
*
* <p>Simply loads {@link Document documents} using the standard JAXP-configured
* XML parser. If you want to change the {@link DocumentBuilder} that is used to
* load documents, then one strategy is to define a corresponding Java system property
* when starting your JVM. For example, to use the Oracle {@link DocumentBuilder},
* you might start your application like as follows:
*
* <pre code="class">java -Djavax.xml.parsers.DocumentBuilderFactory=oracle.xml.jaxp.JXDocumentBuilderFactory MyMainClass</pre>
*
* @author Rob Harrop
* @author Juergen Hoeller
* @since 2.0
*/
public class DefaultDocumentLoader implements DocumentLoader {
/**
* JAXP attribute used to configure the schema language for validation.
*/
private static final String SCHEMA_LANGUAGE_ATTRIBUTE = "http://java.sun.com/xml/jaxp/properties/schemaLanguage";
/**
* JAXP attribute value indicating the XSD schema language.
*/
private static final String XSD_SCHEMA_LANGUAGE = "http://www.w3.org/2001/XMLSchema";
private static final Log logger = LogFactory.getLog(DefaultDocumentLoader.class);
/**
* Load the {@link Document} at the supplied {@link InputSource} using the standard JAXP-configured
* XML parser.
*/
public Document loadDocument(InputSource inputSource, EntityResolver entityResolver,
ErrorHandler errorHandler, int validationMode, boolean namespaceAware) throws Exception {
DocumentBuilderFactory factory = createDocumentBuilderFactory(validationMode, namespaceAware);
if (logger.isDebugEnabled()) {
logger.debug("Using JAXP provider [" + factory.getClass().getName() + "]");
}
DocumentBuilder builder = createDocumentBuilder(factory, entityResolver, errorHandler);
return builder.parse(inputSource);
}
/**
* Create the {@link DocumentBuilderFactory} instance.
* @param validationMode the type of validation: {@link XmlValidationModeDetector#VALIDATION_DTD DTD}
* or {@link XmlValidationModeDetector#VALIDATION_XSD XSD})
* @param namespaceAware whether the returned factory is to provide support for XML namespaces
* @return the JAXP DocumentBuilderFactory
* @throws ParserConfigurationException if we failed to build a proper DocumentBuilderFactory
*/
protected DocumentBuilderFactory createDocumentBuilderFactory(int validationMode, boolean namespaceAware)
throws ParserConfigurationException {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(namespaceAware);
if (validationMode != XmlValidationModeDetector.VALIDATION_NONE) {
factory.setValidating(true);
if (validationMode == XmlValidationModeDetector.VALIDATION_XSD) {
// Enforce namespace aware for XSD...
factory.setNamespaceAware(true);
try {
factory.setAttribute(SCHEMA_LANGUAGE_ATTRIBUTE, XSD_SCHEMA_LANGUAGE);
}
catch (IllegalArgumentException ex) {
ParserConfigurationException pcex = new ParserConfigurationException(
"Unable to validate using XSD: Your JAXP provider [" + factory +
"] does not support XML Schema. Are you running on Java 1.4 with Apache Crimson? " +
"Upgrade to Apache Xerces (or Java 1.5) for full XSD support.");
pcex.initCause(ex);
throw pcex;
}
}
}
return factory;
}
/**
* Create a JAXP DocumentBuilder that this bean definition reader
* will use for parsing XML documents. Can be overridden in subclasses,
* adding further initialization of the builder.
* @param factory the JAXP DocumentBuilderFactory that the DocumentBuilder
* should be created with
* @param entityResolver the SAX EntityResolver to use
* @param errorHandler the SAX ErrorHandler to use
* @return the JAXP DocumentBuilder
* @throws ParserConfigurationException if thrown by JAXP methods
*/
protected DocumentBuilder createDocumentBuilder(
DocumentBuilderFactory factory, EntityResolver entityResolver, ErrorHandler errorHandler)
throws ParserConfigurationException {
DocumentBuilder docBuilder = factory.newDocumentBuilder();
if (entityResolver != null) {
docBuilder.setEntityResolver(entityResolver);
}
if (errorHandler != null) {
docBuilder.setErrorHandler(errorHandler);
}
return docBuilder;
}
}
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