/*
* Copyright 2002-2010 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.web.context.support;
import java.io.IOException;
import java.util.Enumeration;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import javax.servlet.ServletContext;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.io.UrlResource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.util.ResourceUtils;
import org.springframework.util.StringUtils;
/**
* ServletContext-aware subclass of {@link PathMatchingResourcePatternResolver},
* able to find matching resources below the web application root directory
* via Servlet 2.3's <code>ServletContext.getResourcePaths</code>.
* Falls back to the superclass' file system checking for other resources.
*
* @author Juergen Hoeller
* @since 1.1.2
*/
public class ServletContextResourcePatternResolver extends PathMatchingResourcePatternResolver {
private static final Log logger = LogFactory.getLog(ServletContextResourcePatternResolver.class);
/**
* Create a new ServletContextResourcePatternResolver.
* @param servletContext the ServletContext to load resources with
* @see ServletContextResourceLoader#ServletContextResourceLoader(javax.servlet.ServletContext)
*/
public ServletContextResourcePatternResolver(ServletContext servletContext) {
super(new ServletContextResourceLoader(servletContext));
}
/**
* Create a new ServletContextResourcePatternResolver.
* @param resourceLoader the ResourceLoader to load root directories and
* actual resources with
*/
public ServletContextResourcePatternResolver(ResourceLoader resourceLoader) {
super(resourceLoader);
}
/**
* Overridden version which checks for ServletContextResource
* and uses <code>ServletContext.getResourcePaths</code> to find
* matching resources below the web application root directory.
* In case of other resources, delegates to the superclass version.
* @see #doRetrieveMatchingServletContextResources
* @see ServletContextResource
* @see javax.servlet.ServletContext#getResourcePaths
*/
@Override
protected Set<Resource> doFindPathMatchingFileResources(Resource rootDirResource, String subPattern)
throws IOException {
if (rootDirResource instanceof ServletContextResource) {
ServletContextResource scResource = (ServletContextResource) rootDirResource;
ServletContext sc = scResource.getServletContext();
String fullPattern = scResource.getPath() + subPattern;
Set<Resource> result = new LinkedHashSet<Resource>(8);
doRetrieveMatchingServletContextResources(sc, fullPattern, scResource.getPath(), result);
return result;
}
else {
return super.doFindPathMatchingFileResources(rootDirResource, subPattern);
}
}
/**
* Recursively retrieve ServletContextResources that match the given pattern,
* adding them to the given result set.
* @param servletContext the ServletContext to work on
* @param fullPattern the pattern to match against,
* with preprended root directory path
* @param dir the current directory
* @param result the Set of matching Resources to add to
* @throws IOException if directory contents could not be retrieved
* @see ServletContextResource
* @see javax.servlet.ServletContext#getResourcePaths
*/
protected void doRetrieveMatchingServletContextResources(
ServletContext servletContext, String fullPattern, String dir, Set<Resource> result)
throws IOException {
Set candidates = servletContext.getResourcePaths(dir);
if (candidates != null) {
boolean dirDepthNotFixed = fullPattern.contains("**");
int jarFileSep = fullPattern.indexOf(ResourceUtils.JAR_URL_SEPARATOR);
String jarFilePath = null;
String pathInJarFile = null;
if (jarFileSep > 0 && jarFileSep + ResourceUtils.JAR_URL_SEPARATOR.length() < fullPattern.length()) {
jarFilePath = fullPattern.substring(0, jarFileSep);
pathInJarFile = fullPattern.substring(jarFileSep + ResourceUtils.JAR_URL_SEPARATOR.length());
}
for (Object candidate : candidates) {
String currPath = (String) candidate;
if (!currPath.startsWith(dir)) {
// Returned resource path does not start with relative directory:
// assuming absolute path returned -> strip absolute path.
int dirIndex = currPath.indexOf(dir);
if (dirIndex != -1) {
currPath = currPath.substring(dirIndex);
}
}
if (currPath.endsWith("/") && (dirDepthNotFixed || StringUtils.countOccurrencesOf(currPath, "/") <=
StringUtils.countOccurrencesOf(fullPattern, "/"))) {
// Search subdirectories recursively: ServletContext.getResourcePaths
// only returns entries for one directory level.
doRetrieveMatchingServletContextResources(servletContext, fullPattern, currPath, result);
}
if (jarFilePath != null && getPathMatcher().match(jarFilePath, currPath)) {
// Base pattern matches a jar file - search for matching entries within.
String absoluteJarPath = servletContext.getRealPath(currPath);
if (absoluteJarPath != null) {
doRetrieveMatchingJarEntries(absoluteJarPath, pathInJarFile, result);
}
}
if (getPathMatcher().match(fullPattern, currPath)) {
result.add(new ServletContextResource(servletContext, currPath));
}
}
}
}
/**
* Method extracts entries from the given jar by pattern.
* @param jarFilePath the path to the jar file
* @param entryPattern the pattern for jar entries to match
* @param result the Set of matching Resources to add to
* @throws IOException if jar contents could not be retrieved
*/
@SuppressWarnings("unchecked")
private void doRetrieveMatchingJarEntries(String jarFilePath, String entryPattern, Set<Resource> result) {
if (logger.isDebugEnabled()) {
logger.debug("Searching jar file [" + jarFilePath + "] for entries matching [" + entryPattern + "]");
}
try {
JarFile jarFile = new JarFile(jarFilePath);
for (Enumeration<JarEntry> entries = jarFile.entries(); entries.hasMoreElements();) {
JarEntry entry = entries.nextElement();
String entryPath = entry.getName();
if (getPathMatcher().match(entryPattern, entryPath)) {
result.add(new UrlResource(ResourceUtils.URL_PROTOCOL_JAR + ":" +
ResourceUtils.URL_PROTOCOL_FILE + ":" + jarFilePath +
ResourceUtils.JAR_URL_SEPARATOR + entryPath));
}
}
}
catch (IOException ex) {
if (logger.isWarnEnabled()) {
logger.warn("Cannot search for matching resources in jar file [" + jarFilePath +
"] because the jar cannot be opened through the file system", ex);
}
}
}
}