pathmatchingresourcepatternresolver.java

一个关于Spring框架的示例应用程序,简单使用,可以参考.

/*
 * Copyright 2002-2004 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.core.io.support;

import java.io.File;
import java.io.IOException;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
import org.springframework.core.io.UrlResource;
import org.springframework.util.Assert;
import org.springframework.util.PathMatcher;
import org.springframework.util.StringUtils;

/**
 * ResourcePatternResolver implementation that applies Ant-style path matching,
 * using Spring's PathMatcher class.
 *
 * <p>Locations can either be suitable for <code>ResourceLoader.getResource</code>
 * (URLs like "file:C:/context.xml", pseudo-URLs like "classpath:/context.xml",
 * relative file paths like "/WEB-INF/context.xml"), or Ant-style patterns
 * like "/WEB-INF/*-context.xml".
 *
 * <p>In the pattern case, the location has to be resolvable to <code>java.io.File</code>
 * or to a "jar:" URL (leading to a <code>java.net.JarURLConnection</code>)
 * to allow for searching though the specified directory tree. In particular,
 * this is not guaranteed to work with a WAR file that is not expanded.
 *
 * <p>There is special support for retrieving multiple class path resources with the
 * same name, via the "classpath*" prefix. For example, "classpath*:META-INF/beans.xml"
 * will find all beans.xml files in the class path, be it in "classes" directories
 * or in JAR files. This is particularly useful for auto-detecting config files
 * of the same name at the same location within each jar file.
 *
 * <p>The "classpath*" prefix can also be combined with a PathMatcher pattern, for
 * example "classpath*:META-INF/*-beans.xml". In this case, all matching resources
 * in the class path will be found, even if multiple resources of the same name
 * exist in different jar files. Note that "classpath*:" will only work with at
 * least one root directory before the pattern starts.
 *
 * <p>Warning: Ant-style patterns with "classpath:" resources are not guaranteed to
 * find matching resources if the root package to search is available in multiple
 * class path locations. Preferably, use "classpath*:" with the same Ant-style
 * pattern in such a case, which will search <i>all</i> class path locations that
 * contain the root package.
 *
 * <p>If neither given a PathMatcher pattern nor a "classpath*:" location, this
 * resolver will return a single resource via the underlying ResourceLoader.
 *
 * @author Juergen Hoeller
 * @since 1.0.2
 * @see #CLASSPATH_URL_PREFIX
 * @see org.springframework.util.PathMatcher
 * @see org.springframework.core.io.ResourceLoader#getResource
 */
public class PathMatchingResourcePatternResolver implements ResourcePatternResolver {

	protected final Log logger = LogFactory.getLog(getClass());

	private final ResourceLoader resourceLoader;

	private ClassLoader classLoader;


	/**
	 * Create a new PathMatchingResourcePatternResolver with a DefaultResourceLoader.
	 * <p>ClassLoader access will happen via the thread context class loader on actual
	 * access (applying to the thread that does the "getResources" call)
	 * @see org.springframework.core.io.DefaultResourceLoader
	 */
	public PathMatchingResourcePatternResolver() {
		this.resourceLoader = new DefaultResourceLoader();
	}

	/**
	 * Create a new PathMatchingResourcePatternResolver with a DefaultResourceLoader.
	 * @param classLoader the ClassLoader to load classpath resources with,
	 * or null for using the thread context class loader on actual access
	 * (applying to the thread that does the "getResources" call)
	 * @see org.springframework.core.io.DefaultResourceLoader
	 */
	public PathMatchingResourcePatternResolver(ClassLoader classLoader) {
		this.resourceLoader = new DefaultResourceLoader(classLoader);
		this.classLoader = classLoader;
	}

	/**
	 * Create a new PathMatchingResourcePatternResolver.
	 * <p>ClassLoader access will happen via the thread context class loader on actual
	 * access (applying to the thread that does the "getResources" call)
	 * @param resourceLoader the ResourceLoader to load root directories and
	 * actual resources with
	 */
	public PathMatchingResourcePatternResolver(ResourceLoader resourceLoader) {
		this.resourceLoader = resourceLoader;
	}

	/**
	 * Create a new PathMatchingResourcePatternResolver.
	 * @param resourceLoader the ResourceLoader to load root directories and
	 * actual resources with
	 * @param classLoader the ClassLoader to load classpath resources with,
	 * or null for using the thread context class loader on actual access
	 * (applying to the thread that does the "getResources" call)
	 */
	public PathMatchingResourcePatternResolver(ResourceLoader resourceLoader, ClassLoader classLoader) {
		this.resourceLoader = resourceLoader;
		this.classLoader = classLoader;
	}

	/**
	 * Return the ResourceLoader that this pattern resolver works with.
	 */
	public ResourceLoader getResourceLoader() {
		return resourceLoader;
	}

	/**
	 * Return the ClassLoader that this pattern resolver works with,
	 * or null if using the thread context class loader on actual access
	 * (applying to the thread that does the "getResources" call).
	 */
	public ClassLoader getClassLoader() {
		return classLoader;
	}


	public Resource getResource(String location) {
		return this.resourceLoader.getResource(location);
	}

	public Resource[] getResources(String locationPattern) throws IOException {
		Assert.notNull(locationPattern, "locationPattern is required");
		if (locationPattern.startsWith(CLASSPATH_URL_PREFIX)) {
			// a class path resource (multiple resources for same name possible)
			if (PathMatcher.isPattern(locationPattern.substring(CLASSPATH_URL_PREFIX.length()))) {
				// a class path resource pattern
				return findPathMatchingResources(locationPattern);
			}
			else {
				// all class path resources with the given name
				return findAllClassPathResources(locationPattern.substring(CLASSPATH_URL_PREFIX.length()));
			}
		}
		else {
			if (PathMatcher.isPattern(locationPattern)) {
				// a file pattern
				return findPathMatchingResources(locationPattern);
			}
			else {
				// a single resource with the given name
				return new Resource[] {this.resourceLoader.getResource(locationPattern)};
			}
		}
	}

	/**
	 * Find all class location resources with the given location via the ClassLoader.
	 * @param location the absolute path within the classpath
	 * @return the result as Resource array
	 * @throws IOException in case of I/O errors
	 * @see java.lang.ClassLoader#getResources
	 */
	protected Resource[] findAllClassPathResources(String location) throws IOException {