/*
* Copyright 2002-2013 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 com.xiongyingqi.util;
import java.io.File;
import java.io.FileNotFoundException;
import java.net.*;
/**
* 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.
* method can resolve any location to a 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
*/
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 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 JBoss jar file: "vfszip"
*/
public static final String URL_PROTOCOL_VFSZIP = "vfszip";
/**
* URL protocol for a JBoss VFS resource: "vfs"
*/
public static final String URL_PROTOCOL_VFS = "vfs";
/**
* URL protocol for an entry from a WebSphere jar file: "wsjar"
*/
public static final String URL_PROTOCOL_WSJAR = "wsjar";
/**
* 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 java.io.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());
URL url = ClassUtils.getDefaultClassLoader().getResource(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 java.io.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 + "]";
URL url = ClassUtils.getDefaultClassLoader().getResource(path);
if (url == null) {
throw new FileNotFoundException(
description + " cannot be resolved to absolute file path " +
"because it does not reside in the file system"
);
}
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 java.io.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 java.io.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 java.io.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 java.io.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" 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) || protocol.startsWith(URL_PROTOCOL_VFS));
}
/**
* Determine whether the given URL points to a resource in a jar file,
* that is, has protocol "jar", "zip", "wsjar" or "code-source".
* <p>"zip" and "wsjar" are used by WebLogic Server and WebSphere, respectively,
* but can be treated like jar files.
*
* @param url the URL to check
* @return whether the URL has been identified as a JAR URL
*/
public static boolean isJarURL(URL url) {
String up = url.getProtocol();
return (URL_PROTOCOL_JAR.equals(up) || URL_PROTOCOL_ZIP.equals(up) || URL_PROTOCOL_WSJAR.equals(up));
}
/**
* 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 java.net.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 java.net.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 java.net.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 java.net.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"));
}
}