Spring Framework example source code file (ServletContextResourcePatternResolver.java)

This example Spring Framework source code file (ServletContextResourcePatternResolver.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

io, ioexception, iterator, linkedhashset, pathmatchingresourcepatternresolver, servlet, servletcontext, servletcontextresource, servletcontextresource, servletcontextresourceloader, servletcontextresourcepatternresolver, servletcontextresourcepatternresolver, set, set, string, string, util

The Spring Framework ServletContextResourcePatternResolver.java source code

/*
 * 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.web.context.support;

import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.Set;

import javax.servlet.ServletContext;

import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
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.
 * Falls back to the superclass' file system checking for other resources.
 *
 * @author Juergen Hoeller
 * @since 1.1.2
 */
public class ServletContextResourcePatternResolver extends PathMatchingResourcePatternResolver {

	/**
	 * 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 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
	 */
	protected Set 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 result = new LinkedHashSet(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 result) throws IOException {

		Set candidates = servletContext.getResourcePaths(dir);
		if (candidates != null) {
			boolean dirDepthNotFixed = (fullPattern.indexOf("**") != -1);
			for (Iterator it = candidates.iterator(); it.hasNext();) {
				String currPath = (String) it.next();
				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 (getPathMatcher().match(fullPattern, currPath)) {
					result.add(new ServletContextResource(servletContext, currPath));
				}
			}
		}
	}

}