xmlbeandefinitionreader.java

spring api 源代码

/*
 * 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 java.io.IOException;
import java.io.InputStream;

import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.xml.sax.EntityResolver;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.BeanDefinitionStoreException;
import org.springframework.beans.factory.parsing.EmptyReaderEventListener;
import org.springframework.beans.factory.parsing.FailFastProblemReporter;
import org.springframework.beans.factory.parsing.NullSourceExtractor;
import org.springframework.beans.factory.parsing.ProblemReporter;
import org.springframework.beans.factory.parsing.ReaderEventListener;
import org.springframework.beans.factory.parsing.SourceExtractor;
import org.springframework.beans.factory.support.AbstractBeanDefinitionReader;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.core.Constants;
import org.springframework.core.io.DescriptiveResource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.io.support.EncodedResource;
import org.springframework.util.Assert;
import org.springframework.util.xml.SimpleSaxErrorHandler;
import org.springframework.util.xml.XmlValidationModeDetector;

/**
 * Bean definition reader for XML bean definitions.
 * Delegates the actual XML document reading to an implementation
 * of the {@link BeanDefinitionDocumentReader} interface.
 *
 * <p>Typically applied to a
 * {@link org.springframework.beans.factory.support.DefaultListableBeanFactory}
 * or a {@link org.springframework.context.support.GenericApplicationContext}.
 *
 * <p>This class loads a DOM document and applies the BeanDefinitionDocumentReader to it.
 * The document reader will register each bean definition with the given bean factory,
 * talking to the latter's implementation of the
 * {@link org.springframework.beans.factory.support.BeanDefinitionRegistry} interface.
 *
 * @author Juergen Hoeller
 * @author Rob Harrop
 * @since 26.11.2003
 * @see #setDocumentReaderClass
 * @see BeanDefinitionDocumentReader
 * @see DefaultBeanDefinitionDocumentReader
 * @see BeanDefinitionRegistry
 * @see org.springframework.beans.factory.support.DefaultListableBeanFactory
 * @see org.springframework.context.support.GenericApplicationContext
 */
public class XmlBeanDefinitionReader extends AbstractBeanDefinitionReader {

	/**
	 * Indicates that the validation should be disabled.
	 */
	public static final int VALIDATION_NONE = 0;

	/**
	 * Indicates that the validation mode should be detected automatically.
	 */
	public static final int VALIDATION_AUTO = XmlValidationModeDetector.VALIDATION_AUTO;

	/**
	 * Indicates that DTD validation should be used.
	 */
	public static final int VALIDATION_DTD = XmlValidationModeDetector.VALIDATION_DTD;

	/**
	 * Indicates that XSD validation should be used.
	 */
	public static final int VALIDATION_XSD = XmlValidationModeDetector.VALIDATION_XSD;


	/** Constants instance for this class */
	private static final Constants constants = new Constants(XmlBeanDefinitionReader.class);

	private boolean namespaceAware;

	private int validationMode = VALIDATION_AUTO;

	private Class parserClass;

	private Class documentReaderClass = DefaultBeanDefinitionDocumentReader.class;

	private ProblemReporter problemReporter = new FailFastProblemReporter();

	private ReaderEventListener eventListener = new EmptyReaderEventListener();

	private SourceExtractor sourceExtractor = new NullSourceExtractor();

	private NamespaceHandlerResolver namespaceHandlerResolver;

	private DocumentLoader documentLoader = new DefaultDocumentLoader();

	private EntityResolver entityResolver;

	private ErrorHandler errorHandler = new SimpleSaxErrorHandler(logger);

	private final XmlValidationModeDetector validationModeDetector = new XmlValidationModeDetector();


	/**
	 * Create new XmlBeanDefinitionReader for the given bean factory.
	 * @param beanFactory the BeanFactory to load bean definitions into,
	 * in the form of a BeanDefinitionRegistry
	 */
	public XmlBeanDefinitionReader(BeanDefinitionRegistry beanFactory) {
		super(beanFactory);
	}


	/**
	 * Set whether or not the XML parser should be XML namespace aware.
	 * Default is "false".
	 */
	public void setNamespaceAware(boolean namespaceAware) {
		this.namespaceAware = namespaceAware;
	}

	/**
	 * Set if the XML parser should validate the document and thus enforce a DTD.
	 * @deprecated as of Spring 2.0: superseded by "validationMode"
	 * @see #setValidationMode
	 */
	public void setValidating(boolean validating) {
		this.validationMode = (validating ? VALIDATION_AUTO : VALIDATION_NONE);
	}

	/**
	 * Set the validation mode to use by name. Defaults to {@link #VALIDATION_AUTO}.
	 */
	public void setValidationModeName(String validationModeName) {
		setValidationMode(constants.asNumber(validationModeName).intValue());
	}

	/**
	 * Set the validation mode to use. Defaults to {@link #VALIDATION_AUTO}.
	 */
	public void setValidationMode(int validationMode) {
		this.validationMode = validationMode;
	}

	/**
	 * Specify which {@link org.springframework.beans.factory.parsing.ProblemReporter} to use. Default implementation is
	 * {@link org.springframework.beans.factory.parsing.FailFastProblemReporter} which exhibits fail fast behaviour. External tools
	 * can provide an alternative implementation that collates errors and warnings for
	 * display in the tool UI.
	 */
	public void setProblemReporter(ProblemReporter problemReporter) {
		this.problemReporter = (problemReporter != null ? problemReporter : new FailFastProblemReporter());
	}

	/**
	 * Specify which {@link ReaderEventListener} to use. Default implementation is
	 * EmptyReaderEventListener which discards every event notification. External tools
	 * can provide an alternative implementation to monitor the components being registered
	 * in the BeanFactory.
	 */
	public void setEventListener(ReaderEventListener eventListener) {
		this.eventListener = (eventListener != null ? eventListener : new EmptyReaderEventListener());
	}

	/**
	 * Specify the {@link SourceExtractor} to use. The default implementation is
	 * {@link NullSourceExtractor} which simply returns <code>null</code> as the source object.
	 * This means that during normal runtime execution no additional source metadata is attached
	 * to the bean configuration metadata.
	 */
	public void setSourceExtractor(SourceExtractor sourceExtractor) {
		this.sourceExtractor = (sourceExtractor != null ? sourceExtractor : new NullSourceExtractor());
	}

	/**
	 * Specify the {@link NamespaceHandlerResolver} to use. If none is specified a default
	 * instance will be created by {@link #createDefaultNamespaceHandlerResolver()}.
	 */
	public void setNamespaceHandlerResolver(NamespaceHandlerResolver namespaceHandlerResolver) {
		this.namespaceHandlerResolver = namespaceHandlerResolver;
	}

	/**
	 * Specify the {@link DocumentLoader} to use. The default implementation is
	 * {@link DefaultDocumentLoader} which loads {@link Document} instances using JAXP.
	 */
	public void setDocumentLoader(DocumentLoader documentLoader) {
		this.documentLoader = (documentLoader != null ? documentLoader : new DefaultDocumentLoader());
	}

	/**
	 * Set a SAX entity resolver to be used for parsing. By default,
	 * BeansDtdResolver will be used. Can be overridden for custom entity
	 * resolution, for example relative to some specific base path.
	 * @see BeansDtdResolver
	 */
	public void setEntityResolver(EntityResolver entityResolver) {
		this.entityResolver = entityResolver;
	}

	/**
	 * Return the EntityResolver to use, building a default resolver
	 * if none specified.
	 */
	protected EntityResolver getEntityResolver() {
		if (this.entityResolver == null) {
			// Determine default EntityResolver to use.
			ResourceLoader resourceLoader = getResourceLoader();
			if (resourceLoader != null) {
				this.entityResolver = new ResourceEntityResolver(resourceLoader);
			}
			else {
				this.entityResolver = new DelegatingEntityResolver(getBeanClassLoader());
			}
		}
		return this.entityResolver;
	}

	/**
	 * Set an implementation of the <code>org.xml.sax.ErrorHandler</code>
	 * interface for custom handling of XML parsing errors and warnings.
	 * <p>If not set, a default SimpleSaxErrorHandler is used that simply
	 * logs warnings using the logger instance of the view class,
	 * and rethrows errors to discontinue the XML transformation.
	 * @see SimpleSaxErrorHandler
	 */
	public void setErrorHandler(ErrorHandler errorHandler) {
		this.errorHandler = errorHandler;
	}