/*
* Copyright 2002-2014 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.hotswap.agent.util.spring.util;
import java.io.File;
import java.io.FileNotFoundException;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.URLConnection;
/**
* Utility methods for resolving resource locations to files in the file system.
* Mainly for internal use within the framework.
*
* <p>
* Consider using Spring's Resource abstraction in the core package for handling
* all kinds of file resources in a uniform manner.
* {@link org.hotswap.agent.util.spring.io.loader.springframework.core.io.ResourceLoader}
* 's {@code getResource()} method can resolve any location to a
* {@link org.hotswap.agent.util.spring.io.resource.springframework.core.io.Resource}
* object, which in turn allows one to obtain a {@code java.io.File} in the file
* system through its {@code getFile()} method.
*
* <p>
* The main reason for these utility methods for resource location handling is
* to support {@link Log4jConfigurer}, which must be able to resolve resource
* locations <i>before the logging system has been initialized</i>. Spring's
* {@code Resource} abstraction in the core package, on the other hand, already
* expects the logging system to be available.
*
* @author Juergen Hoeller
* @since 1.1.5
* @see org.hotswap.agent.util.spring.io.resource.springframework.core.io.
* Resource
* @see org.hotswap.agent.util.spring.io.resource.springframework.core.io.
* ClassPathResource
* @see org.hotswap.agent.util.spring.io.resource.springframework.core.io.
* FileSystemResource
* @see org.hotswap.agent.util.spring.io.resource.springframework.core.io.
* UrlResource
* @see org.hotswap.agent.util.spring.io.loader.springframework.core.io.
* ResourceLoader
*/
public abstract class ResourceUtils {
/** Pseudo URL prefix for loading from the class path: "classpath:" */
public static final String CLASSPATH_URL_PREFIX = "classpath:";
/** URL prefix for loading from the file system: "file:" */
public static final String FILE_URL_PREFIX = "file:";
/** URL prefix for loading from the file system: "jar:" */
public static final String JAR_URL_PREFIX = "jar:";
/** URL protocol for a file in the file system: "file" */
public static final String URL_PROTOCOL_FILE = "file";
/** URL protocol for an entry from a jar file: "jar" */
public static final String URL_PROTOCOL_JAR = "jar";
/** URL protocol for an entry from a zip file: "zip" */
public static final String URL_PROTOCOL_ZIP = "zip";
/** URL protocol for an entry from a WebSphere jar file: "wsjar" */
public static final String URL_PROTOCOL_WSJAR = "wsjar";
/** URL protocol for an entry from a JBoss jar file: "vfszip" */
public static final String URL_PROTOCOL_VFSZIP = "vfszip";
/** URL protocol for a JBoss file system resource: "vfsfile" */
public static final String URL_PROTOCOL_VFSFILE = "vfsfile";
/** URL protocol for a general JBoss VFS resource: "vfs" */
public static final String URL_PROTOCOL_VFS = "vfs";
/** File extension for a regular jar file: ".jar" */
public static final String JAR_FILE_EXTENSION = ".jar";
/** Separator between JAR URL and file path within the JAR: "!/" */
public static final String JAR_URL_SEPARATOR = "!/";
/**
* Return whether the given resource location is a URL: either a special
* "classpath" pseudo URL or a standard URL.
*
* @param resourceLocation
* the location String to check
* @return whether the location qualifies as a URL
* @see #CLASSPATH_URL_PREFIX
* @see java.net.URL
*/
public static boolean isUrl(String resourceLocation) {
if (resourceLocation == null) {
return false;
}
if (resourceLocation.startsWith(CLASSPATH_URL_PREFIX)) {
return true;
}
try {
new URL(resourceLocation);
return true;
} catch (MalformedURLException ex) {
return false;
}
}
/**
* Resolve the given resource location to a {@code java.net.URL}.
* <p>
* Does not check whether the URL actually exists; simply returns the URL
* that the given location would correspond to.
*
* @param resourceLocation
* the resource location to resolve: either a "classpath:" pseudo
* URL, a "file:" URL, or a plain file path
* @return a corresponding URL object
* @throws FileNotFoundException
* if the resource cannot be resolved to a URL
*/
public static URL getURL(String resourceLocation) throws FileNotFoundException {
Assert.notNull(resourceLocation, "Resource location must not be null");
if (resourceLocation.startsWith(CLASSPATH_URL_PREFIX)) {
String path = resourceLocation.substring(CLASSPATH_URL_PREFIX.length());
ClassLoader cl = ClassUtils.getDefaultClassLoader();
URL url = (cl != null ? cl.getResource(path) : ClassLoader.getSystemResource(path));
if (url == null) {
String description = "class path resource [" + path + "]";
throw new FileNotFoundException(description + " cannot be resolved to URL because it does not exist");
}
return url;
}
try {
// try URL
return new URL(resourceLocation);
} catch (MalformedURLException ex) {
// no URL -> treat as file path
try {
return new File(resourceLocation).toURI().toURL();
} catch (MalformedURLException ex2) {
throw new FileNotFoundException("Resource location [" + resourceLocation + "] is neither a URL not a well-formed file path");
}
}
}
/**
* Resolve the given resource location to a {@code java.io.File}, i.e. to a
* file in the file system.
* <p>
* Does not check whether the file actually exists; simply returns the File
* that the given location would correspond to.
*
* @param resourceLocation
* the resource location to resolve: either a "classpath:" pseudo
* URL, a "file:" URL, or a plain file path
* @return a corresponding File object
* @throws FileNotFoundException
* if the resource cannot be resolved to a file in the file
* system
*/
public static File getFile(String resourceLocation) throws FileNotFoundException {
Assert.notNull(resourceLocation, "Resource location must not be null");
if (resourceLocation.startsWith(CLASSPATH_URL_PREFIX)) {
String path = resourceLocation.substring(CLASSPATH_URL_PREFIX.length());
String description = "class path resource [" + path + "]";
ClassLoader cl = ClassUtils.getDefaultClassLoader();
URL url = (cl != null ? cl.getResource(path) : ClassLoader.getSystemResource(path));
if (url == null) {
throw new FileNotFoundException(description + " cannot be resolved to absolute file path because it does not exist");
}
return getFile(url, description);
}
try {
// try URL
return getFile(new URL(resourceLocation));
} catch (MalformedURLException ex) {
// no URL -> treat as file path
return new File(resourceLocation);
}
}
/**
* Resolve the given resource URL to a {@code java.io.File}, i.e. to a file
* in the file system.
*
* @param resourceUrl
* the resource URL to resolve
* @return a corresponding File object
* @throws FileNotFoundException
* if the URL cannot be resolved to a file in the file system
*/
public static File getFile(URL resourceUrl) throws FileNotFoundException {
return getFile(resourceUrl, "URL");
}
/**
* Resolve the given resource URL to a {@code java.io.File}, i.e. to a file
* in the file system.
*
* @param resourceUrl
* the resource URL to resolve
* @param description
* a description of the original resource that the URL was
* created for (for example, a class path location)
* @return a corresponding File object
* @throws FileNotFoundException
* if the URL cannot be resolved to a file in the file system
*/
public static File getFile(URL resourceUrl, String description) throws FileNotFoundException {
Assert.notNull(resourceUrl, "Resource URL must not be null");
if (!URL_PROTOCOL_FILE.equals(resourceUrl.getProtocol())) {
throw new FileNotFoundException(description + " cannot be resolved to absolute file path " + "because it does not reside in the file system: " + resourceUrl);
}
try {
return new File(toURI(resourceUrl).getSchemeSpecificPart());
} catch (URISyntaxException ex) {
// Fallback for URLs that are not valid URIs (should hardly ever
// happen).
return new File(resourceUrl.getFile());
}
}
/**
* Resolve the given resource URI to a {@code java.io.File}, i.e. to a file
* in the file system.
*
* @param resourceUri
* the resource URI to resolve
* @return a corresponding File object
* @throws FileNotFoundException
* if the URL cannot be resolved to a file in the file system
*/
public static File getFile(URI resourceUri) throws FileNotFoundException {
return getFile(resourceUri, "URI");
}
/**
* Resolve the given resource URI to a {@code java.io.File}, i.e. to a file
* in the file system.
*
* @param resourceUri
* the resource URI to resolve
* @param description
* a description of the original resource that the URI was
* created for (for example, a class path location)
* @return a corresponding File object
* @throws FileNotFoundException
* if the URL cannot be resolved to a file in the file system
*/
public static File getFile(URI resourceUri, String description) throws FileNotFoundException {
Assert.notNull(resourceUri, "Resource URI must not be null");
if (!URL_PROTOCOL_FILE.equals(resourceUri.getScheme())) {
throw new FileNotFoundException(description + " cannot be resolved to absolute file path " + "because it does not reside in the file system: " + resourceUri);
}
return new File(resourceUri.getSchemeSpecificPart());
}
/**
* Determine whether the given URL points to a resource in the file system,
* that is, has protocol "file", "vfsfile" or "vfs".
*
* @param url
* the URL to check
* @return whether the URL has been identified as a file system URL
*/
public static boolean isFileURL(URL url) {
String protocol = url.getProtocol();
return (URL_PROTOCOL_FILE.equals(protocol) || URL_PROTOCOL_VFSFILE.equals(protocol) || URL_PROTOCOL_VFS.equals(protocol));
}
/**
* Determine whether the given URL points to a resource in a jar file, that
* is, has protocol "jar", "zip", "vfszip" or "wsjar".
*
* @param url
* the URL to check
* @return whether the URL has been identified as a JAR URL
*/
public static boolean isJarURL(URL url) {
String protocol = url.getProtocol();
return (URL_PROTOCOL_JAR.equals(protocol) || URL_PROTOCOL_ZIP.equals(protocol) || URL_PROTOCOL_VFSZIP.equals(protocol) || URL_PROTOCOL_WSJAR.equals(protocol));
}
/**
* Determine whether the given URL points to a jar file itself, that is, has
* protocol "file" and ends with the ".jar" extension.
*
* @param url
* the URL to check
* @return whether the URL has been identified as a JAR file URL
* @since 4.1
*/
public static boolean isJarFileURL(URL url) {
return (URL_PROTOCOL_FILE.equals(url.getProtocol()) && url.getPath().toLowerCase().endsWith(JAR_FILE_EXTENSION));
}
/**
* Extract the URL for the actual jar file from the given URL (which may
* point to a resource in a jar file or to a jar file itself).
*
* @param jarUrl
* the original URL
* @return the URL for the actual jar file
* @throws MalformedURLException
* if no valid jar file URL could be extracted
*/
public static URL extractJarFileURL(URL jarUrl) throws MalformedURLException {
String urlFile = jarUrl.getFile();
int separatorIndex = urlFile.indexOf(JAR_URL_SEPARATOR);
if (separatorIndex != -1) {
String jarFile = urlFile.substring(0, separatorIndex);
try {
return new URL(jarFile);
} catch (MalformedURLException ex) {
// Probably no protocol in original jar URL, like
// "jar:C:/mypath/myjar.jar".
// This usually indicates that the jar file resides in the file
// system.
if (!jarFile.startsWith("/")) {
jarFile = "/" + jarFile;
}
return new URL(FILE_URL_PREFIX + jarFile);
}
} else {
return jarUrl;
}
}
/**
* Create a URI instance for the given URL, replacing spaces with "%20" URI
* encoding first.
* <p>
* Furthermore, this method works on JDK 1.4 as well, in contrast to the
* {@code URL.toURI()} method.
*
* @param url
* the URL to convert into a URI instance
* @return the URI instance
* @throws URISyntaxException
* if the URL wasn't a valid URI
* @see java.net.URL#toURI()
*/
public static URI toURI(URL url) throws URISyntaxException {
return toURI(url.toString());
}
/**
* Create a URI instance for the given location String, replacing spaces
* with "%20" URI encoding first.
*
* @param location
* the location String to convert into a URI instance
* @return the URI instance
* @throws URISyntaxException
* if the location wasn't a valid URI
*/
public static URI toURI(String location) throws URISyntaxException {
return new URI(StringUtils.replace(location, " ", "%20"));
}
/**
* Set the {@link URLConnection#setUseCaches "useCaches"} flag on the given
* connection, preferring {@code false} but leaving the flag at {@code true}
* for JNLP based resources.
*
* @param con
* the URLConnection to set the flag on
*/
public static void useCachesIfNecessary(URLConnection con) {
con.setUseCaches(con.getClass().getSimpleName().startsWith("JNLP"));
}
}