https://github.com/spring-projects/spring-framework: Spring Core (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2020 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
 *
 *      https://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.FileNotFoundException;
import java.io.IOException;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.net.JarURLConnection;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLClassLoader;
import java.net.URLConnection;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.zip.ZipException;

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.core.io.VfsResource;
import org.springframework.lang.Nullable;
import org.springframework.util.AntPathMatcher;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.PathMatcher;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.ResourceUtils;
import org.springframework.util.StringUtils;


A ResourcePatternResolver implementation that is able to resolve a specified resource location path into one or more matching Resources. The source path may be a simple path which has a one-to-one mapping to a target Resource, or alternatively may contain the special "classpath*:" prefix and/or internal Ant-style regular expressions (matched using Spring's AntPathMatcher utility). Both of the latter are effectively wildcards. 
No Wildcards:

In the simple case, if the specified location path does not start with the "classpath*:" prefix, and does not contain a PathMatcher pattern, this resolver will simply return a single resource via a getResource() call on the underlying ResourceLoader. Examples are real URLs such as "file:C:/context.xml", pseudo-URLs such as "classpath:/context.xml", and simple unprefixed paths such as "/WEB-INF/context.xml". The latter will resolve in a fashion specific to the underlying ResourceLoader (e.g. ServletContextResource for a WebApplicationContext). 
Ant-style Patterns:

When the path location contains an Ant-style pattern, e.g.:

/WEB-INF/*-context.xml
com/mycompany/**/applicationContext.xml
file:C:/some/path/*-context.xml
classpath:com/mycompany/**/applicationContext.xml
 the resolver follows a more complex but defined procedure to try to resolve the wildcard. It produces a Resource for the path up to the last non-wildcard segment and obtains a URL from it. If this URL is not a "jar:" URL or container-specific variant (e.g. "zip:" in WebLogic, "wsjar" in WebSphere", etc.), then a java.io.File is obtained from it, and used to resolve the wildcard by walking the filesystem. In the case of a jar URL, the resolver either gets a java.net.JarURLConnection from it, or manually parses the jar URL, and then traverses the contents of the jar file, to resolve the wildcards. 
Implications on portability:

If the specified path is already a file URL (either explicitly, or implicitly because the base ResourceLoader is a filesystem one, then wildcarding is guaranteed to work in a completely portable fashion. 
If the specified path is a classpath location, then the resolver must obtain the last non-wildcard path segment URL via a Classloader.getResource() call. Since this is just a node of the path (not the file at the end) it is actually undefined (in the ClassLoader Javadocs) exactly what sort of a URL is returned in this case. In practice, it is usually a java.io.File representing the directory, where the classpath resource resolves to a filesystem location, or a jar URL of some sort, where the classpath resource resolves to a jar location. Still, there is a portability concern on this operation. 
If a jar URL is obtained for the last non-wildcard segment, the resolver must be able to get a java.net.JarURLConnection from it, or manually parse the jar URL, to be able to walk the contents of the jar, and resolve the wildcard. This will work in most environments, but will fail in others, and it is strongly recommended that the wildcard resolution of resources coming from jars be thoroughly tested in your specific environment before you rely on it. 
classpath*: Prefix:

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 autodetecting config files of the same name at the same location within each jar file. Internally, this happens via a ClassLoader.getResources() call, and is completely portable. 
The "classpath*:" prefix can also be combined with a PathMatcher pattern in the rest of the location path, for example "classpath*:META-INF/*-beans.xml". In this case, the resolution strategy is fairly simple: a ClassLoader.getResources() call is used on the last non-wildcard path segment to get all the matching resources in the class loader hierarchy, and then off each resource the same PathMatcher resolution strategy described above is used for the wildcard subpath. 
Other notes:

WARNING: Note that "classpath*:" when combined with Ant-style patterns will only work reliably with at least one root directory before the pattern starts, unless the actual target files reside in the file system. This means that a pattern like "classpath*:*.xml" will not retrieve files from the root of jar files but rather only from the root of expanded directories. This originates from a limitation in the JDK's ClassLoader.getResources() method which only returns file system locations for a passed-in empty String (indicating potential roots to search). This ResourcePatternResolver implementation is trying to mitigate the jar root lookup limitation through URLClassLoader introspection and "java.class.path" manifest evaluation; however, without portability guarantees. 
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. This is because a resource such as

    com/mycompany/package1/service-context.xml


may be in only one location, but when a path such as

    classpath:com/mycompany/**/service-context.xml

 is used to try to resolve it, the resolver will work off the (first) URL returned by getResource("com/mycompany");. If this base package node exists in multiple classloader locations, the actual end resource may not be underneath. Therefore, preferably, use "classpath*:" with the same Ant-style pattern in such a case, which will search all class path
locations that contain the root package.

Author:Juergen Hoeller, Colin Sampaleanu, Marius Bogoevici, Costin Leau, Phillip Webb
See Also:
Since:1.0.2
/**
 * A {@link ResourcePatternResolver} implementation that is able to resolve a
 * specified resource location path into one or more matching Resources.
 * The source path may be a simple path which has a one-to-one mapping to a
 * target {@link org.springframework.core.io.Resource}, or alternatively
 * may contain the special "{@code classpath*:}" prefix and/or
 * internal Ant-style regular expressions (matched using Spring's
 * {@link org.springframework.util.AntPathMatcher} utility).
 * Both of the latter are effectively wildcards.
 *
 * <p><b>No Wildcards:</b>
 *
 * <p>In the simple case, if the specified location path does not start with the
 * {@code "classpath*:}" prefix, and does not contain a PathMatcher pattern,
 * this resolver will simply return a single resource via a
 * {@code getResource()} call on the underlying {@code ResourceLoader}.
 * Examples are real URLs such as "{@code file:C:/context.xml}", pseudo-URLs
 * such as "{@code classpath:/context.xml}", and simple unprefixed paths
 * such as "{@code /WEB-INF/context.xml}". The latter will resolve in a
 * fashion specific to the underlying {@code ResourceLoader} (e.g.
 * {@code ServletContextResource} for a {@code WebApplicationContext}).
 *
 * <p><b>Ant-style Patterns:</b>
 *
 * <p>When the path location contains an Ant-style pattern, e.g.:
 * <pre class="code">
 * /WEB-INF/*-context.xml
 * com/mycompany/**&#47;applicationContext.xml
 * file:C:/some/path/*-context.xml
 * classpath:com/mycompany/**&#47;applicationContext.xml</pre>
 * the resolver follows a more complex but defined procedure to try to resolve
 * the wildcard. It produces a {@code Resource} for the path up to the last
 * non-wildcard segment and obtains a {@code URL} from it. If this URL is
 * not a "{@code jar:}" URL or container-specific variant (e.g.
 * "{@code zip:}" in WebLogic, "{@code wsjar}" in WebSphere", etc.),
 * then a {@code java.io.File} is obtained from it, and used to resolve the
 * wildcard by walking the filesystem. In the case of a jar URL, the resolver
 * either gets a {@code java.net.JarURLConnection} from it, or manually parses
 * the jar URL, and then traverses the contents of the jar file, to resolve the
 * wildcards.
 *
 * <p><b>Implications on portability:</b>
 *
 * <p>If the specified path is already a file URL (either explicitly, or
 * implicitly because the base {@code ResourceLoader} is a filesystem one,
 * then wildcarding is guaranteed to work in a completely portable fashion.
 *
 * <p>If the specified path is a classpath location, then the resolver must
 * obtain the last non-wildcard path segment URL via a
 * {@code Classloader.getResource()} call. Since this is just a
 * node of the path (not the file at the end) it is actually undefined
 * (in the ClassLoader Javadocs) exactly what sort of a URL is returned in
 * this case. In practice, it is usually a {@code java.io.File} representing
 * the directory, where the classpath resource resolves to a filesystem
 * location, or a jar URL of some sort, where the classpath resource resolves
 * to a jar location. Still, there is a portability concern on this operation.
 *
 * <p>If a jar URL is obtained for the last non-wildcard segment, the resolver
 * must be able to get a {@code java.net.JarURLConnection} from it, or
 * manually parse the jar URL, to be able to walk the contents of the jar,
 * and resolve the wildcard. This will work in most environments, but will
 * fail in others, and it is strongly recommended that the wildcard
 * resolution of resources coming from jars be thoroughly tested in your
 * specific environment before you rely on it.
 *
 * <p><b>{@code classpath*:} Prefix:</b>
 *
 * <p>There is special support for retrieving multiple class path resources with
 * the same name, via the "{@code classpath*:}" prefix. For example,
 * "{@code 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 autodetecting config files of the same name
 * at the same location within each jar file. Internally, this happens via a
 * {@code ClassLoader.getResources()} call, and is completely portable.
 *
 * <p>The "classpath*:" prefix can also be combined with a PathMatcher pattern in
 * the rest of the location path, for example "classpath*:META-INF/*-beans.xml".
 * In this case, the resolution strategy is fairly simple: a
 * {@code ClassLoader.getResources()} call is used on the last non-wildcard
 * path segment to get all the matching resources in the class loader hierarchy,
 * and then off each resource the same PathMatcher resolution strategy described
 * above is used for the wildcard subpath.
 *
 * <p><b>Other notes:</b>
 *
 * <p><b>WARNING:</b> Note that "{@code classpath*:}" when combined with
 * Ant-style patterns will only work reliably with at least one root directory
 * before the pattern starts, unless the actual target files reside in the file
 * system. This means that a pattern like "{@code classpath*:*.xml}" will
 * <i>not</i> retrieve files from the root of jar files but rather only from the
 * root of expanded directories. This originates from a limitation in the JDK's
 * {@code ClassLoader.getResources()} method which only returns file system
 * locations for a passed-in empty String (indicating potential roots to search).
 * This {@code ResourcePatternResolver} implementation is trying to mitigate the
 * jar root lookup limitation through {@link URLClassLoader} introspection and
 * "java.class.path" manifest evaluation; however, without portability guarantees.
 *
 * <p><b>WARNING:</b> 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. This is because a resource such as
 * <pre class="code">
 *     com/mycompany/package1/service-context.xml
 * </pre>
 * may be in only one location, but when a path such as
 * <pre class="code">
 *     classpath:com/mycompany/**&#47;service-context.xml
 * </pre>
 * is used to try to resolve it, the resolver will work off the (first) URL
 * returned by {@code getResource("com/mycompany");}. If this base package node
 * exists in multiple classloader locations, the actual end resource may not be
 * underneath. Therefore, preferably, use "{@code 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.
 *
 * @author Juergen Hoeller
 * @author Colin Sampaleanu
 * @author Marius Bogoevici
 * @author Costin Leau
 * @author Phillip Webb
 * @since 1.0.2
 * @see #CLASSPATH_ALL_URL_PREFIX
 * @see org.springframework.util.AntPathMatcher
 * @see org.springframework.core.io.ResourceLoader#getResource(String)
 * @see ClassLoader#getResources(String)
 */
public class PathMatchingResourcePatternResolver implements ResourcePatternResolver {

	private static final Log logger = LogFactory.getLog(PathMatchingResourcePatternResolver.class);

	@Nullable
	private static Method equinoxResolveMethod;

	static {
		try {
			// Detect Equinox OSGi (e.g. on WebSphere 6.1)
			Class<?> fileLocatorClass = ClassUtils.forName("org.eclipse.core.runtime.FileLocator",
					PathMatchingResourcePatternResolver.class.getClassLoader());
			equinoxResolveMethod = fileLocatorClass.getMethod("resolve", URL.class);
			logger.trace("Found Equinox FileLocator for OSGi bundle URL resolution");
		}
		catch (Throwable ex) {
			equinoxResolveMethod = null;
		}
	}


	private final ResourceLoader resourceLoader;

	private PathMatcher pathMatcher = new AntPathMatcher();


	
Create a new PathMatchingResourcePatternResolver with a DefaultResourceLoader.

ClassLoader access will happen via the thread context class loader.

See Also:
  • DefaultResourceLoader
/**
	 * Create a new PathMatchingResourcePatternResolver with a DefaultResourceLoader.
	 * <p>ClassLoader access will happen via the thread context class loader.
	 * @see org.springframework.core.io.DefaultResourceLoader
	 */
	public PathMatchingResourcePatternResolver() {
		this.resourceLoader = new DefaultResourceLoader();
	}

	
Create a new PathMatchingResourcePatternResolver.

ClassLoader access will happen via the thread context class loader.

Params:
  • resourceLoader – the ResourceLoader to load root directories and
actual resources with
/**
	 * Create a new PathMatchingResourcePatternResolver.
	 * <p>ClassLoader access will happen via the thread context class loader.
	 * @param resourceLoader the ResourceLoader to load root directories and
	 * actual resources with
	 */
	public PathMatchingResourcePatternResolver(ResourceLoader resourceLoader) {
		Assert.notNull(resourceLoader, "ResourceLoader must not be null");
		this.resourceLoader = resourceLoader;
	}

	
Create a new PathMatchingResourcePatternResolver with a DefaultResourceLoader.

Params:
  • classLoader – the ClassLoader to load classpath resources with, or null for using the thread context class loader at the time of actual resource access
See Also:
/**
	 * Create a new PathMatchingResourcePatternResolver with a DefaultResourceLoader.
	 * @param classLoader the ClassLoader to load classpath resources with,
	 * or {@code null} for using the thread context class loader
	 * at the time of actual resource access
	 * @see org.springframework.core.io.DefaultResourceLoader
	 */
	public PathMatchingResourcePatternResolver(@Nullable ClassLoader classLoader) {
		this.resourceLoader = new DefaultResourceLoader(classLoader);
	}


	
Return the ResourceLoader that this pattern resolver works with.

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

	@Override
	@Nullable
	public ClassLoader getClassLoader() {
		return getResourceLoader().getClassLoader();
	}

	
Set the PathMatcher implementation to use for this
resource pattern resolver. Default is AntPathMatcher.

See Also:
  • AntPathMatcher
/**
	 * Set the PathMatcher implementation to use for this
	 * resource pattern resolver. Default is AntPathMatcher.
	 * @see org.springframework.util.AntPathMatcher
	 */
	public void setPathMatcher(PathMatcher pathMatcher) {
		Assert.notNull(pathMatcher, "PathMatcher must not be null");
		this.pathMatcher = pathMatcher;
	}

	
Return the PathMatcher that this resource pattern resolver uses.

/**
	 * Return the PathMatcher that this resource pattern resolver uses.
	 */
	public PathMatcher getPathMatcher() {
		return this.pathMatcher;
	}


	@Override
	public Resource getResource(String location) {
		return getResourceLoader().getResource(location);
	}

	@Override
	public Resource[] getResources(String locationPattern) throws IOException {
		Assert.notNull(locationPattern, "Location pattern must not be null");
		if (locationPattern.startsWith(CLASSPATH_ALL_URL_PREFIX)) {
			// a class path resource (multiple resources for same name possible)
			if (getPathMatcher().isPattern(locationPattern.substring(CLASSPATH_ALL_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_ALL_URL_PREFIX.length()));
			}
		}
		else {
			// Generally only look for a pattern after a prefix here,
			// and on Tomcat only after the "*/" separator for its "war:" protocol.
			int prefixEnd = (locationPattern.startsWith("war:") ? locationPattern.indexOf("*/") + 1 :
					locationPattern.indexOf(':') + 1);
			if (getPathMatcher().isPattern(locationPattern.substring(prefixEnd))) {
				// a file pattern
				return findPathMatchingResources(locationPattern);
			}
			else {
				// a single resource with the given name
				return new Resource[] {getResourceLoader().getResource(locationPattern)};
			}
		}
	}

	
Find all class location resources with the given location via the ClassLoader. Delegates to doFindAllClassPathResources(String). 
Params:
  • location – the absolute path within the classpath
Throws:
See Also:
Returns:the result as Resource array
/**
	 * Find all class location resources with the given location via the ClassLoader.
	 * Delegates to {@link #doFindAllClassPathResources(String)}.
	 * @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
	 * @see #convertClassLoaderURL
	 */
	protected Resource[] findAllClassPathResources(String location) throws IOException {
		String path = location;
		if (path.startsWith("/")) {
			path = path.substring(1);
		}
		Set<Resource> result = doFindAllClassPathResources(path);
		if (logger.isTraceEnabled()) {
			logger.trace("Resolved classpath location [" + location + "] to resources " + result);
		}
		return result.toArray(new Resource[0]);
	}

	
Find all class location resources with the given path via the ClassLoader. Called by findAllClassPathResources(String). 
Params:
  • path – the absolute path within the classpath (never a leading slash)
Returns:a mutable Set of matching Resource instances
Since:4.1.1
/**
	 * Find all class location resources with the given path via the ClassLoader.
	 * Called by {@link #findAllClassPathResources(String)}.
	 * @param path the absolute path within the classpath (never a leading slash)
	 * @return a mutable Set of matching Resource instances
	 * @since 4.1.1
	 */
	protected Set<Resource> doFindAllClassPathResources(String path) throws IOException {
		Set<Resource> result = new LinkedHashSet<>(16);
		ClassLoader cl = getClassLoader();
		Enumeration<URL> resourceUrls = (cl != null ? cl.getResources(path) : ClassLoader.getSystemResources(path));
		while (resourceUrls.hasMoreElements()) {
			URL url = resourceUrls.nextElement();
			result.add(convertClassLoaderURL(url));
		}
		if (!StringUtils.hasLength(path)) {
			// The above result is likely to be incomplete, i.e. only containing file system references.
			// We need to have pointers to each of the jar files on the classpath as well...
			addAllClassLoaderJarRoots(cl, result);
		}
		return result;
	}

	
Convert the given URL as returned from the ClassLoader into a Resource. 
The default implementation simply creates a UrlResource instance. 
Params:
  • url – a URL as returned from the ClassLoader
See Also:
Returns:the corresponding Resource object
/**
	 * Convert the given URL as returned from the ClassLoader into a {@link Resource}.
	 * <p>The default implementation simply creates a {@link UrlResource} instance.
	 * @param url a URL as returned from the ClassLoader
	 * @return the corresponding Resource object
	 * @see java.lang.ClassLoader#getResources
	 * @see org.springframework.core.io.Resource
	 */
	protected Resource convertClassLoaderURL(URL url) {
		return new UrlResource(url);
	}

	
Search all URLClassLoader URLs for jar file references and add them to the given set of resources in the form of pointers to the root of the jar file content. 
Params:
  • classLoader – the ClassLoader to search (including its ancestors)
  • result – the set of resources to add jar roots to
Since:4.1.1
/**
	 * Search all {@link URLClassLoader} URLs for jar file references and add them to the
	 * given set of resources in the form of pointers to the root of the jar file content.
	 * @param classLoader the ClassLoader to search (including its ancestors)
	 * @param result the set of resources to add jar roots to
	 * @since 4.1.1
	 */
	protected void addAllClassLoaderJarRoots(@Nullable ClassLoader classLoader, Set<Resource> result) {
		if (classLoader instanceof URLClassLoader) {
			try {
				for (URL url : ((URLClassLoader) classLoader).getURLs()) {
					try {
						UrlResource jarResource = (ResourceUtils.URL_PROTOCOL_JAR.equals(url.getProtocol()) ?
								new UrlResource(url) :
								new UrlResource(ResourceUtils.JAR_URL_PREFIX + url + ResourceUtils.JAR_URL_SEPARATOR));
						if (jarResource.exists()) {
							result.add(jarResource);
						}
					}
					catch (MalformedURLException ex) {
						if (logger.isDebugEnabled()) {
							logger.debug("Cannot search for matching files underneath [" + url +
									"] because it cannot be converted to a valid 'jar:' URL: " + ex.getMessage());
						}
					}
				}
			}
			catch (Exception ex) {
				if (logger.isDebugEnabled()) {
					logger.debug("Cannot introspect jar files since ClassLoader [" + classLoader +
							"] does not support 'getURLs()': " + ex);
				}
			}
		}

		if (classLoader == ClassLoader.getSystemClassLoader()) {
			// "java.class.path" manifest evaluation...
			addClassPathManifestEntries(result);
		}

		if (classLoader != null) {
			try {
				// Hierarchy traversal...
				addAllClassLoaderJarRoots(classLoader.getParent(), result);
			}
			catch (Exception ex) {
				if (logger.isDebugEnabled()) {
					logger.debug("Cannot introspect jar files in parent ClassLoader since [" + classLoader +
							"] does not support 'getParent()': " + ex);
				}
			}
		}
	}

	
Determine jar file references from the "java.class.path." manifest property and add them
to the given set of resources in the form of pointers to the root of the jar file content.

Params:
  • result – the set of resources to add jar roots to
Since:4.3
/**
	 * Determine jar file references from the "java.class.path." manifest property and add them
	 * to the given set of resources in the form of pointers to the root of the jar file content.
	 * @param result the set of resources to add jar roots to
	 * @since 4.3
	 */
	protected void addClassPathManifestEntries(Set<Resource> result) {
		try {
			String javaClassPathProperty = System.getProperty("java.class.path");
			for (String path : StringUtils.delimitedListToStringArray(
					javaClassPathProperty, System.getProperty("path.separator"))) {
				try {
					String filePath = new File(path).getAbsolutePath();
					int prefixIndex = filePath.indexOf(':');
					if (prefixIndex == 1) {
						// Possibly "c:" drive prefix on Windows, to be upper-cased for proper duplicate detection
						filePath = StringUtils.capitalize(filePath);
					}
					// # can appear in directories/filenames, java.net.URL should not treat it as a fragment
					filePath = StringUtils.replace(filePath, "#", "%23");
					// Build URL that points to the root of the jar file
					UrlResource jarResource = new UrlResource(ResourceUtils.JAR_URL_PREFIX +
							ResourceUtils.FILE_URL_PREFIX + filePath + ResourceUtils.JAR_URL_SEPARATOR);
					// Potentially overlapping with URLClassLoader.getURLs() result above!
					if (!result.contains(jarResource) && !hasDuplicate(filePath, result) && jarResource.exists()) {
						result.add(jarResource);
					}
				}
				catch (MalformedURLException ex) {
					if (logger.isDebugEnabled()) {
						logger.debug("Cannot search for matching files underneath [" + path +
								"] because it cannot be converted to a valid 'jar:' URL: " + ex.getMessage());
					}
				}
			}
		}
		catch (Exception ex) {
			if (logger.isDebugEnabled()) {
				logger.debug("Failed to evaluate 'java.class.path' manifest entries: " + ex);
			}
		}
	}

	
Check whether the given file path has a duplicate but differently structured entry
in the existing result, i.e. with or without a leading slash.

Params:
  • filePath – the file path (with or without a leading slash)
  • result – the current result
Returns:true if there is a duplicate (i.e. to ignore the given file path), false to proceed with adding a corresponding resource to the current result
/**
	 * Check whether the given file path has a duplicate but differently structured entry
	 * in the existing result, i.e. with or without a leading slash.
	 * @param filePath the file path (with or without a leading slash)
	 * @param result the current result
	 * @return {@code true} if there is a duplicate (i.e. to ignore the given file path),
	 * {@code false} to proceed with adding a corresponding resource to the current result
	 */
	private boolean hasDuplicate(String filePath, Set<Resource> result) {
		if (result.isEmpty()) {
			return false;
		}
		String duplicatePath = (filePath.startsWith("/") ? filePath.substring(1) : "/" + filePath);
		try {
			return result.contains(new UrlResource(ResourceUtils.JAR_URL_PREFIX + ResourceUtils.FILE_URL_PREFIX +
					duplicatePath + ResourceUtils.JAR_URL_SEPARATOR));
		}
		catch (MalformedURLException ex) {
			// Ignore: just for testing against duplicate.
			return false;
		}
	}

	
Find all resources that match the given location pattern via the
Ant-style PathMatcher. Supports resources in jar files and zip files
and in the file system.

Params:
  • locationPattern – the location pattern to match
Throws:
See Also:
Returns:the result as Resource array
/**
	 * Find all resources that match the given location pattern via the
	 * Ant-style PathMatcher. Supports resources in jar files and zip files
	 * and in the file system.
	 * @param locationPattern the location pattern to match
	 * @return the result as Resource array
	 * @throws IOException in case of I/O errors
	 * @see #doFindPathMatchingJarResources
	 * @see #doFindPathMatchingFileResources
	 * @see org.springframework.util.PathMatcher
	 */
	protected Resource[] findPathMatchingResources(String locationPattern) throws IOException {
		String rootDirPath = determineRootDir(locationPattern);
		String subPattern = locationPattern.substring(rootDirPath.length());
		Resource[] rootDirResources = getResources(rootDirPath);
		Set<Resource> result = new LinkedHashSet<>(16);
		for (Resource rootDirResource : rootDirResources) {
			rootDirResource = resolveRootDirResource(rootDirResource);
			URL rootDirUrl = rootDirResource.getURL();
			if (equinoxResolveMethod != null && rootDirUrl.getProtocol().startsWith("bundle")) {
				URL resolvedUrl = (URL) ReflectionUtils.invokeMethod(equinoxResolveMethod, null, rootDirUrl);
				if (resolvedUrl != null) {
					rootDirUrl = resolvedUrl;
				}
				rootDirResource = new UrlResource(rootDirUrl);
			}
			if (rootDirUrl.getProtocol().startsWith(ResourceUtils.URL_PROTOCOL_VFS)) {
				result.addAll(VfsResourceMatchingDelegate.findMatchingResources(rootDirUrl, subPattern, getPathMatcher()));
			}
			else if (ResourceUtils.isJarURL(rootDirUrl) || isJarResource(rootDirResource)) {
				result.addAll(doFindPathMatchingJarResources(rootDirResource, rootDirUrl, subPattern));
			}
			else {
				result.addAll(doFindPathMatchingFileResources(rootDirResource, subPattern));
			}
		}
		if (logger.isTraceEnabled()) {
			logger.trace("Resolved location pattern [" + locationPattern + "] to resources " + result);
		}
		return result.toArray(new Resource[0]);
	}

	
Determine the root directory for the given location.

Used for determining the starting point for file matching, resolving the root directory location to a java.io.File and passing it into retrieveMatchingFiles, with the remainder of the location as pattern. 
Will return "/WEB-INF/" for the pattern "/WEB-INF/*.xml",
for example.

Params:
  • location – the location to check
See Also:
Returns:the part of the location that denotes the root directory
/**
	 * Determine the root directory for the given location.
	 * <p>Used for determining the starting point for file matching,
	 * resolving the root directory location to a {@code java.io.File}
	 * and passing it into {@code retrieveMatchingFiles}, with the
	 * remainder of the location as pattern.
	 * <p>Will return "/WEB-INF/" for the pattern "/WEB-INF/*.xml",
	 * for example.
	 * @param location the location to check
	 * @return the part of the location that denotes the root directory
	 * @see #retrieveMatchingFiles
	 */
	protected String determineRootDir(String location) {
		int prefixEnd = location.indexOf(':') + 1;
		int rootDirEnd = location.length();
		while (rootDirEnd > prefixEnd && getPathMatcher().isPattern(location.substring(prefixEnd, rootDirEnd))) {
			rootDirEnd = location.lastIndexOf('/', rootDirEnd - 2) + 1;
		}
		if (rootDirEnd == 0) {
			rootDirEnd = prefixEnd;
		}
		return location.substring(0, rootDirEnd);
	}

	
Resolve the specified resource for path matching.

By default, Equinox OSGi "bundleresource:" / "bundleentry:" URL will be
resolved into a standard jar file URL that be traversed using Spring's
standard jar file traversal algorithm. For any preceding custom resolution,
override this method and replace the resource handle accordingly.

Params:
  • original – the resource to resolve
Throws:
Returns:the resolved resource (may be identical to the passed-in resource)
/**
	 * Resolve the specified resource for path matching.
	 * <p>By default, Equinox OSGi "bundleresource:" / "bundleentry:" URL will be
	 * resolved into a standard jar file URL that be traversed using Spring's
	 * standard jar file traversal algorithm. For any preceding custom resolution,
	 * override this method and replace the resource handle accordingly.
	 * @param original the resource to resolve
	 * @return the resolved resource (may be identical to the passed-in resource)
	 * @throws IOException in case of resolution failure
	 */
	protected Resource resolveRootDirResource(Resource original) throws IOException {
		return original;
	}

	
Return whether the given resource handle indicates a jar resource that the doFindPathMatchingJarResources method can handle. 
By default, the URL protocols "jar", "zip", "vfszip and "wsjar" will be treated as jar resources. This template method allows for detecting further kinds of jar-like resources, e.g. through instanceof checks on the resource handle type. 
Params:
  • resource – the resource handle to check
(usually the root directory to start path matching from)
See Also:
/**
	 * Return whether the given resource handle indicates a jar resource
	 * that the {@code doFindPathMatchingJarResources} method can handle.
	 * <p>By default, the URL protocols "jar", "zip", "vfszip and "wsjar"
	 * will be treated as jar resources. This template method allows for
	 * detecting further kinds of jar-like resources, e.g. through
	 * {@code instanceof} checks on the resource handle type.
	 * @param resource the resource handle to check
	 * (usually the root directory to start path matching from)
	 * @see #doFindPathMatchingJarResources
	 * @see org.springframework.util.ResourceUtils#isJarURL
	 */
	protected boolean isJarResource(Resource resource) throws IOException {
		return false;
	}

	
Find all resources in jar files that match the given location pattern
via the Ant-style PathMatcher.

Params:
  • rootDirResource – the root directory as Resource
  • rootDirURL – the pre-resolved root directory URL
  • subPattern – the sub pattern to match (below the root directory)
Throws:
See Also:
Returns:a mutable Set of matching Resource instances
Since:4.3
/**
	 * Find all resources in jar files that match the given location pattern
	 * via the Ant-style PathMatcher.
	 * @param rootDirResource the root directory as Resource
	 * @param rootDirURL the pre-resolved root directory URL
	 * @param subPattern the sub pattern to match (below the root directory)
	 * @return a mutable Set of matching Resource instances
	 * @throws IOException in case of I/O errors
	 * @since 4.3
	 * @see java.net.JarURLConnection
	 * @see org.springframework.util.PathMatcher
	 */
	protected Set<Resource> doFindPathMatchingJarResources(Resource rootDirResource, URL rootDirURL, String subPattern)
			throws IOException {

		URLConnection con = rootDirURL.openConnection();
		JarFile jarFile;
		String jarFileUrl;
		String rootEntryPath;
		boolean closeJarFile;

		if (con instanceof JarURLConnection) {
			// Should usually be the case for traditional JAR files.
			JarURLConnection jarCon = (JarURLConnection) con;
			ResourceUtils.useCachesIfNecessary(jarCon);
			jarFile = jarCon.getJarFile();
			jarFileUrl = jarCon.getJarFileURL().toExternalForm();
			JarEntry jarEntry = jarCon.getJarEntry();
			rootEntryPath = (jarEntry != null ? jarEntry.getName() : "");
			closeJarFile = !jarCon.getUseCaches();
		}
		else {
			// No JarURLConnection -> need to resort to URL file parsing.
			// We'll assume URLs of the format "jar:path!/entry", with the protocol
			// being arbitrary as long as following the entry format.
			// We'll also handle paths with and without leading "file:" prefix.
			String urlFile = rootDirURL.getFile();
			try {
				int separatorIndex = urlFile.indexOf(ResourceUtils.WAR_URL_SEPARATOR);
				if (separatorIndex == -1) {
					separatorIndex = urlFile.indexOf(ResourceUtils.JAR_URL_SEPARATOR);
				}
				if (separatorIndex != -1) {
					jarFileUrl = urlFile.substring(0, separatorIndex);
					rootEntryPath = urlFile.substring(separatorIndex + 2);  // both separators are 2 chars
					jarFile = getJarFile(jarFileUrl);
				}
				else {
					jarFile = new JarFile(urlFile);
					jarFileUrl = urlFile;
					rootEntryPath = "";
				}
				closeJarFile = true;
			}
			catch (ZipException ex) {
				if (logger.isDebugEnabled()) {
					logger.debug("Skipping invalid jar classpath entry [" + urlFile + "]");
				}
				return Collections.emptySet();
			}
		}

		try {
			if (logger.isTraceEnabled()) {
				logger.trace("Looking for matching resources in jar file [" + jarFileUrl + "]");
			}
			if (StringUtils.hasLength(rootEntryPath) && !rootEntryPath.endsWith("/")) {
				// Root entry path must end with slash to allow for proper matching.
				// The Sun JRE does not return a slash here, but BEA JRockit does.
				rootEntryPath = rootEntryPath + "/";
			}
			Set<Resource> result = new LinkedHashSet<>(8);
			for (Enumeration<JarEntry> entries = jarFile.entries(); entries.hasMoreElements();) {
				JarEntry entry = entries.nextElement();
				String entryPath = entry.getName();
				if (entryPath.startsWith(rootEntryPath)) {
					String relativePath = entryPath.substring(rootEntryPath.length());
					if (getPathMatcher().match(subPattern, relativePath)) {
						result.add(rootDirResource.createRelative(relativePath));
					}
				}
			}
			return result;
		}
		finally {
			if (closeJarFile) {
				jarFile.close();
			}
		}
	}

	
Resolve the given jar file URL into a JarFile object.

/**
	 * Resolve the given jar file URL into a JarFile object.
	 */
	protected JarFile getJarFile(String jarFileUrl) throws IOException {
		if (jarFileUrl.startsWith(ResourceUtils.FILE_URL_PREFIX)) {
			try {
				return new JarFile(ResourceUtils.toURI(jarFileUrl).getSchemeSpecificPart());
			}
			catch (URISyntaxException ex) {
				// Fallback for URLs that are not valid URIs (should hardly ever happen).
				return new JarFile(jarFileUrl.substring(ResourceUtils.FILE_URL_PREFIX.length()));
			}
		}
		else {
			return new JarFile(jarFileUrl);
		}
	}

	
Find all resources in the file system that match the given location pattern
via the Ant-style PathMatcher.

Params:
  • rootDirResource – the root directory as Resource
  • subPattern – the sub pattern to match (below the root directory)
Throws:
See Also:
Returns:a mutable Set of matching Resource instances
/**
	 * Find all resources in the file system that match the given location pattern
	 * via the Ant-style PathMatcher.
	 * @param rootDirResource the root directory as Resource
	 * @param subPattern the sub pattern to match (below the root directory)
	 * @return a mutable Set of matching Resource instances
	 * @throws IOException in case of I/O errors
	 * @see #retrieveMatchingFiles
	 * @see org.springframework.util.PathMatcher
	 */
	protected Set<Resource> doFindPathMatchingFileResources(Resource rootDirResource, String subPattern)
			throws IOException {

		File rootDir;
		try {
			rootDir = rootDirResource.getFile().getAbsoluteFile();
		}
		catch (FileNotFoundException ex) {
			if (logger.isDebugEnabled()) {
				logger.debug("Cannot search for matching files underneath " + rootDirResource +
						" in the file system: " + ex.getMessage());
			}
			return Collections.emptySet();
		}
		catch (Exception ex) {
			if (logger.isInfoEnabled()) {
				logger.info("Failed to resolve " + rootDirResource + " in the file system: " + ex);
			}
			return Collections.emptySet();
		}
		return doFindMatchingFileSystemResources(rootDir, subPattern);
	}

	
Find all resources in the file system that match the given location pattern
via the Ant-style PathMatcher.

Params:
  • rootDir – the root directory in the file system
  • subPattern – the sub pattern to match (below the root directory)
Throws:
See Also:
Returns:a mutable Set of matching Resource instances
/**
	 * Find all resources in the file system that match the given location pattern
	 * via the Ant-style PathMatcher.
	 * @param rootDir the root directory in the file system
	 * @param subPattern the sub pattern to match (below the root directory)
	 * @return a mutable Set of matching Resource instances
	 * @throws IOException in case of I/O errors
	 * @see #retrieveMatchingFiles
	 * @see org.springframework.util.PathMatcher
	 */
	protected Set<Resource> doFindMatchingFileSystemResources(File rootDir, String subPattern) throws IOException {
		if (logger.isTraceEnabled()) {
			logger.trace("Looking for matching resources in directory tree [" + rootDir.getPath() + "]");
		}
		Set<File> matchingFiles = retrieveMatchingFiles(rootDir, subPattern);
		Set<Resource> result = new LinkedHashSet<>(matchingFiles.size());
		for (File file : matchingFiles) {
			result.add(new FileSystemResource(file));
		}
		return result;
	}

	
Retrieve files that match the given path pattern,
checking the given directory and its subdirectories.

Params:
  • rootDir – the directory to start from
  • pattern – the pattern to match against,
relative to the root directory
Throws:
  • IOException – if directory contents could not be retrieved
Returns:a mutable Set of matching Resource instances
/**
	 * Retrieve files that match the given path pattern,
	 * checking the given directory and its subdirectories.
	 * @param rootDir the directory to start from
	 * @param pattern the pattern to match against,
	 * relative to the root directory
	 * @return a mutable Set of matching Resource instances
	 * @throws IOException if directory contents could not be retrieved
	 */
	protected Set<File> retrieveMatchingFiles(File rootDir, String pattern) throws IOException {
		if (!rootDir.exists()) {
			// Silently skip non-existing directories.
			if (logger.isDebugEnabled()) {
				logger.debug("Skipping [" + rootDir.getAbsolutePath() + "] because it does not exist");
			}
			return Collections.emptySet();
		}
		if (!rootDir.isDirectory()) {
			// Complain louder if it exists but is no directory.
			if (logger.isInfoEnabled()) {
				logger.info("Skipping [" + rootDir.getAbsolutePath() + "] because it does not denote a directory");
			}
			return Collections.emptySet();
		}
		if (!rootDir.canRead()) {
			if (logger.isInfoEnabled()) {
				logger.info("Skipping search for matching files underneath directory [" + rootDir.getAbsolutePath() +
						"] because the application is not allowed to read the directory");
			}
			return Collections.emptySet();
		}
		String fullPattern = StringUtils.replace(rootDir.getAbsolutePath(), File.separator, "/");
		if (!pattern.startsWith("/")) {
			fullPattern += "/";
		}
		fullPattern = fullPattern + StringUtils.replace(pattern, File.separator, "/");
		Set<File> result = new LinkedHashSet<>(8);
		doRetrieveMatchingFiles(fullPattern, rootDir, result);
		return result;
	}

	
Recursively retrieve files that match the given pattern,
adding them to the given result list.

Params:
  • fullPattern – the pattern to match against,
with prepended root directory path
  • dir – the current directory
  • result – the Set of matching File instances to add to
Throws:
  • IOException – if directory contents could not be retrieved
/**
	 * Recursively retrieve files that match the given pattern,
	 * adding them to the given result list.
	 * @param fullPattern the pattern to match against,
	 * with prepended root directory path
	 * @param dir the current directory
	 * @param result the Set of matching File instances to add to
	 * @throws IOException if directory contents could not be retrieved
	 */
	protected void doRetrieveMatchingFiles(String fullPattern, File dir, Set<File> result) throws IOException {
		if (logger.isTraceEnabled()) {
			logger.trace("Searching directory [" + dir.getAbsolutePath() +
					"] for files matching pattern [" + fullPattern + "]");
		}
		for (File content : listDirectory(dir)) {
			String currPath = StringUtils.replace(content.getAbsolutePath(), File.separator, "/");
			if (content.isDirectory() && getPathMatcher().matchStart(fullPattern, currPath + "/")) {
				if (!content.canRead()) {
					if (logger.isDebugEnabled()) {
						logger.debug("Skipping subdirectory [" + dir.getAbsolutePath() +
								"] because the application is not allowed to read the directory");
					}
				}
				else {
					doRetrieveMatchingFiles(fullPattern, content, result);
				}
			}
			if (getPathMatcher().match(fullPattern, currPath)) {
				result.add(content);
			}
		}
	}

	
Determine a sorted list of files in the given directory.

Params:
  • dir – the directory to introspect
See Also:
Returns:the sorted list of files (by default in alphabetical order)
Since:5.1
/**
	 * Determine a sorted list of files in the given directory.
	 * @param dir the directory to introspect
	 * @return the sorted list of files (by default in alphabetical order)
	 * @since 5.1
	 * @see File#listFiles()
	 */
	protected File[] listDirectory(File dir) {
		File[] files = dir.listFiles();
		if (files == null) {
			if (logger.isInfoEnabled()) {
				logger.info("Could not retrieve contents of directory [" + dir.getAbsolutePath() + "]");
			}
			return new File[0];
		}
		Arrays.sort(files, Comparator.comparing(File::getName));
		return files;
	}


	
Inner delegate class, avoiding a hard JBoss VFS API dependency at runtime.

/**
	 * Inner delegate class, avoiding a hard JBoss VFS API dependency at runtime.
	 */
	private static class VfsResourceMatchingDelegate {

		public static Set<Resource> findMatchingResources(
				URL rootDirURL, String locationPattern, PathMatcher pathMatcher) throws IOException {

			Object root = VfsPatternUtils.findRoot(rootDirURL);
			PatternVirtualFileVisitor visitor =
					new PatternVirtualFileVisitor(VfsPatternUtils.getPath(root), locationPattern, pathMatcher);
			VfsPatternUtils.visit(root, visitor);
			return visitor.getResources();
		}
	}


	
VFS visitor for path matching purposes.

/**
	 * VFS visitor for path matching purposes.
	 */
	@SuppressWarnings("unused")
	private static class PatternVirtualFileVisitor implements InvocationHandler {

		private final String subPattern;

		private final PathMatcher pathMatcher;

		private final String rootPath;

		private final Set<Resource> resources = new LinkedHashSet<>();

		public PatternVirtualFileVisitor(String rootPath, String subPattern, PathMatcher pathMatcher) {
			this.subPattern = subPattern;
			this.pathMatcher = pathMatcher;
			this.rootPath = (rootPath.isEmpty() || rootPath.endsWith("/") ? rootPath : rootPath + "/");
		}

		@Override
		@Nullable
		public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
			String methodName = method.getName();
			if (Object.class == method.getDeclaringClass()) {
				if (methodName.equals("equals")) {
					// Only consider equal when proxies are identical.
					return (proxy == args[0]);
				}
				else if (methodName.equals("hashCode")) {
					return System.identityHashCode(proxy);
				}
			}
			else if ("getAttributes".equals(methodName)) {
				return getAttributes();
			}
			else if ("visit".equals(methodName)) {
				visit(args[0]);
				return null;
			}
			else if ("toString".equals(methodName)) {
				return toString();
			}

			throw new IllegalStateException("Unexpected method invocation: " + method);
		}

		public void visit(Object vfsResource) {
			if (this.pathMatcher.match(this.subPattern,
					VfsPatternUtils.getPath(vfsResource).substring(this.rootPath.length()))) {
				this.resources.add(new VfsResource(vfsResource));
			}
		}

		@Nullable
		public Object getAttributes() {
			return VfsPatternUtils.getVisitorAttributes();
		}

		public Set<Resource> getResources() {
			return this.resources;
		}

		public int size() {
			return this.resources.size();
		}

		@Override
		public String toString() {
			return "sub-pattern: " + this.subPattern + ", resources: " + this.resources;
		}
	}

}