/*
* Copyright 2002-2009 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.util.Arrays;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
/**
* EntityResolver implementation for the Spring beans DTD,
* to load the DTD from the Spring class path (or JAR file).
*
* <p>Fetches "spring-beans-2.0.dtd" from the class path resource
* "/org/springframework/beans/factory/xml/spring-beans-2.0.dtd",
* no matter whether specified as some local URL that includes "spring-beans"
* in the DTD name or as "http://www.springframework.org/dtd/spring-beans-2.0.dtd".
*
* @author Juergen Hoeller
* @author Colin Sampaleanu
* @since 04.06.2003
* @see ResourceEntityResolver
*/
public class BeansDtdResolver implements EntityResolver {
private static final String DTD_EXTENSION = ".dtd";
private static final String[] DTD_NAMES = {"spring-beans-2.0", "spring-beans"};
private static final Log logger = LogFactory.getLog(BeansDtdResolver.class);
public InputSource resolveEntity(String publicId, String systemId) throws IOException {
if (logger.isTraceEnabled()) {
logger.trace("Trying to resolve XML entity with public ID [" + publicId +
"] and system ID [" + systemId + "]");
}
if (systemId != null && systemId.endsWith(DTD_EXTENSION)) {
int lastPathSeparator = systemId.lastIndexOf("/");
for (String DTD_NAME : DTD_NAMES) {
int dtdNameStart = systemId.indexOf(DTD_NAME);
if (dtdNameStart > lastPathSeparator) {
String dtdFile = systemId.substring(dtdNameStart);
if (logger.isTraceEnabled()) {
logger.trace("Trying to locate [" + dtdFile + "] in Spring jar");
}
try {
Resource resource = new ClassPathResource(dtdFile, getClass());
InputSource source = new InputSource(resource.getInputStream());
source.setPublicId(publicId);
source.setSystemId(systemId);
if (logger.isDebugEnabled()) {
logger.debug("Found beans DTD [" + systemId + "] in classpath: " + dtdFile);
}
return source;
}
catch (IOException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not resolve beans DTD [" + systemId + "]: not found in class path", ex);
}
}
}
}
}
// Use the default behavior -> download from website or wherever.
return null;
}
@Override
public String toString() {
return "EntityResolver for DTDs " + Arrays.toString(DTD_NAMES);
}
}
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