infra.beans.factory.xml.BeansDtdResolver Maven / Gradle / Ivy
/*
* Copyright 2017 - 2024 the original author or authors.
*
* This program 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 3 of the License, or
* (at your option) any later version.
*
* This program 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 this program. If not, see [https://www.gnu.org/licenses/]
*/
package infra.beans.factory.xml;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import java.io.FileNotFoundException;
import java.io.IOException;
import infra.core.io.ClassPathResource;
import infra.core.io.Resource;
import infra.lang.Nullable;
import infra.logging.Logger;
import infra.logging.LoggerFactory;
/**
* {@link EntityResolver} implementation for the Framework beans DTD,
* to load the DTD from the Framework class path (or JAR file).
*
* Fetches "spring-beans.dtd" from the class path resource
* "/infra/beans/factory/xml/spring-beans.dtd",
* no matter whether specified as some local URL that includes "spring-beans"
* in the DTD name or as "https://www.springframework.org/dtd/spring-beans-2.0.dtd".
*
* @author Juergen Hoeller
* @author Colin Sampaleanu
* @see ResourceEntityResolver
* @since 04.06.2003
*/
public class BeansDtdResolver implements EntityResolver {
private static final String DTD_EXTENSION = ".dtd";
private static final String DTD_NAME = "spring-beans";
private static final Logger logger = LoggerFactory.getLogger(BeansDtdResolver.class);
@Override
@Nullable
public InputSource resolveEntity(@Nullable String publicId, @Nullable 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('/');
int dtdNameStart = systemId.indexOf(DTD_NAME, lastPathSeparator);
if (dtdNameStart != -1) {
String dtdFile = DTD_NAME + DTD_EXTENSION;
if (logger.isTraceEnabled()) {
logger.trace("Trying to locate [" + dtdFile + "] in Framework jar on classpath");
}
try {
Resource resource = new ClassPathResource(dtdFile, getClass());
InputSource source = new InputSource(resource.getInputStream());
source.setPublicId(publicId);
source.setSystemId(systemId);
if (logger.isTraceEnabled()) {
logger.trace("Found beans DTD [" + systemId + "] in classpath: " + dtdFile);
}
return source;
}
catch (FileNotFoundException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not resolve beans DTD [" + systemId + "]: not found in classpath", ex);
}
}
}
}
// Fall back to the parser's default behavior.
return null;
}
@Override
public String toString() {
return "EntityResolver for spring-beans DTD";
}
}