/* * 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.File; import java.io.IOException; import java.net.URL; import java.net.URLDecoder; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.springframework.core.io.Resource; import org.springframework.core.io.ResourceLoader; /** * EntityResolver implementation that tries to resolve entity references * through a {@link org.springframework.core.io.ResourceLoader} (usually, * relative to the resource base of an ApplicationContext), if applicable. * Extends {@link DelegatingEntityResolver} to also provide DTD and XSD lookup. * *
Allows to use standard XML entities to include XML snippets into an * application context definition, for example to split a large XML file * into various modules. The include paths can be relative to the * application context's resource base as usual, instead of relative * to the JVM working directory (the XML parser's default). * *
Note: In addition to relative paths, every URL that specifies a * file in the current system root, i.e. the JVM working directory, * will be interpreted relative to the application context too. * * @author Juergen Hoeller * @since 31.07.2003 * @see org.springframework.core.io.ResourceLoader * @see org.springframework.context.ApplicationContext */ public class ResourceEntityResolver extends DelegatingEntityResolver { private static final Log logger = LogFactory.getLog(ResourceEntityResolver.class); private final ResourceLoader resourceLoader; /** * Create a ResourceEntityResolver for the specified ResourceLoader * (usually, an ApplicationContext). * @param resourceLoader the ResourceLoader (or ApplicationContext) * to load XML entity includes with */ public ResourceEntityResolver(ResourceLoader resourceLoader) { super(resourceLoader.getClassLoader()); this.resourceLoader = resourceLoader; } @Override public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException { InputSource source = super.resolveEntity(publicId, systemId); if (source == null && systemId != null) { String resourcePath = null; try { String decodedSystemId = URLDecoder.decode(systemId); String givenUrl = new URL(decodedSystemId).toString(); String systemRootUrl = new File("").toURL().toString(); // Try relative to resource base if currently in system root. if (givenUrl.startsWith(systemRootUrl)) { resourcePath = givenUrl.substring(systemRootUrl.length()); } } catch (Exception ex) { // Typically a MalformedURLException or AccessControlException. if (logger.isDebugEnabled()) { logger.debug("Could not resolve XML entity [" + systemId + "] against system root URL", ex); } // No URL (or no resolvable URL) -> try relative to resource base. resourcePath = systemId; } if (resourcePath != null) { if (logger.isTraceEnabled()) { logger.trace("Trying to locate XML entity [" + systemId + "] as resource [" + resourcePath + "]"); } Resource resource = this.resourceLoader.getResource(resourcePath); source = new InputSource(resource.getInputStream()); source.setPublicId(publicId); source.setSystemId(systemId); if (logger.isDebugEnabled()) { logger.debug("Found XML entity [" + systemId + "]: " + resource); } } } return source; } }