/*
* JBoss, Home of Professional Open Source
* Copyright 2011, Red Hat, Inc., and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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.jboss.solder.servlet.resource;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import org.jboss.solder.logging.Logger;
/**
* This implementation of {@link WebResourceLocationProvider} will try to identify the location of web resources by examining
* the URLs the classloader uses for loading classes. This will only work if the classloader is a {@link URLClassLoader}.
*
* @author Christian Kaltepoth <christian@kaltepoth.de>
*
*/
public class URLClassLoaderResourceProvider implements WebResourceLocationProvider {
private final Logger log = Logger.getLogger(URLClassLoaderResourceProvider.class);
@Override
public int getPrecedence() {
return 100;
}
@Override
public URL getWebResource(String path, ClassLoader classLoader) {
// this class only works for URLClassLoaders
if (classLoader instanceof URLClassLoader) {
URLClassLoader urlClassLoader = (URLClassLoader) classLoader;
// get the URLs of the classloader
for (URL classLoaderUrl : urlClassLoader.getURLs()) {
// try this URL to locate the web resource
URL possibleWebResourceLocation = processClassLoaderSearchPath(classLoaderUrl, path);
// we will use the first result we get
if (possibleWebResourceLocation != null) {
return possibleWebResourceLocation;
}
}
}
// log class loader type in all other cases
else {
if (log.isTraceEnabled()) {
log.trace("Context class loader is not an URLClassLoader but: "
+ (classLoader != null ? classLoader.getClass().getName() : "null"));
}
}
return null;
}
/**
* Try to locate the web resource using the supplied classloader URL.
*
* @param classPathUrl The {@link URL} the classloader uses to look for classes
* @param path The path to lookup (e.g. "/WEB-INF/web.xml")
* @return The guessed location of the web resource or <code>null</code> if it could not be determined
*/
private URL processClassLoaderSearchPath(URL classPathUrl, String path) {
// we use string comparisons here
String location = classPathUrl.toString();
// ignore JAR files as they don't help us
if (location.endsWith(".jar")) {
return null;
}
if (log.isTraceEnabled()) {
log.trace("Found URL of directory: " + location);
}
// should always work as the URL is built using an existing URL
try {
// Works for most containers like Tomcat, Jetty and Glassfish
if (location.endsWith("/WEB-INF/classes/")) {
return new URL(location.substring(0, location.length() - 17) + path);
}
// special hack for the Maven Jetty plugin
if (location.endsWith("/target/classes/")) {
return new URL(location.substring(0, location.length() - 16) + "/src/main/webapp" + path);
}
} catch (MalformedURLException e) {
if (log.isDebugEnabled()) {
log.debug("Failed to create URL instance!", e);
}
}
return null;
}
}