java.lang.Object
- org.springframework.util.ResourceUtils

```
public abstract class ResourceUtils
extends Object
```
Utility methods for resolving resource locations to files in the file system. Mainly for internal use within the framework.
Consider using Spring's Resource abstraction in the core package for handling all kinds of file resources in a uniform manner. ResourceLoader's getResource() method can resolve any location to a Resource object, which in turn allows one to obtain a java.io.File in the file system through its getFile() method.
Since:
1.1.5
Author:
Juergen Hoeller
See Also:
Resource, ClassPathResource, FileSystemResource, UrlResource, ResourceLoader

Field Summary

Fields
Modifier and Type	Field	Description
`static String`	`CLASSPATH_URL_PREFIX`	Pseudo URL prefix for loading from the class path: "classpath:"
`static String`	`FILE_URL_PREFIX`	URL prefix for loading from the file system: "file:"
`static String`	`JAR_FILE_EXTENSION`	File extension for a regular jar file: ".jar"
`static String`	`JAR_URL_PREFIX`	URL prefix for loading from a jar file: "jar:"
`static String`	`JAR_URL_SEPARATOR`	Separator between JAR URL and file path within the JAR: "!/"
`static String`	`URL_PROTOCOL_FILE`	URL protocol for a file in the file system: "file"
`static String`	`URL_PROTOCOL_JAR`	URL protocol for an entry from a jar file: "jar"
`static String`	`URL_PROTOCOL_VFS`	URL protocol for a general JBoss VFS resource: "vfs"
`static String`	`URL_PROTOCOL_VFSFILE`	URL protocol for a JBoss file system resource: "vfsfile"
`static String`	`URL_PROTOCOL_VFSZIP`	URL protocol for an entry from a JBoss jar file: "vfszip"
`static String`	`URL_PROTOCOL_WAR`	URL protocol for an entry from a war file: "war"
`static String`	`URL_PROTOCOL_WSJAR`	URL protocol for an entry from a WebSphere jar file: "wsjar"
`static String`	`URL_PROTOCOL_ZIP`	URL protocol for an entry from a zip file: "zip"
`static String`	`WAR_URL_PREFIX`	URL prefix for loading from a war file on Tomcat: "war:"
`static String`	`WAR_URL_SEPARATOR`	Special separator between WAR URL and jar part on Tomcat

Constructor Summary
Constructors
Constructor Description
ResourceUtils()

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static URL`	`extractArchiveURL(URL jarUrl)`	Extract the URL for the outermost archive from the given jar/war URL (which may point to a resource in a jar file or to a jar file itself).
`static URL`	`extractJarFileURL(URL jarUrl)`	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).
`static File`	`getFile(String resourceLocation)`	Resolve the given resource location to a `java.io.File`, i.e.
`static File`	`getFile(URI resourceUri)`	Resolve the given resource URI to a `java.io.File`, i.e.
`static File`	`getFile(URI resourceUri, String description)`	Resolve the given resource URI to a `java.io.File`, i.e.
`static File`	`getFile(URL resourceUrl)`	Resolve the given resource URL to a `java.io.File`, i.e.
`static File`	`getFile(URL resourceUrl, String description)`	Resolve the given resource URL to a `java.io.File`, i.e.
`static URL`	`getURL(String resourceLocation)`	Resolve the given resource location to a `java.net.URL`.
`static boolean`	`isFileURL(URL url)`	Determine whether the given URL points to a resource in the file system, i.e.
`static boolean`	`isJarFileURL(URL url)`	Determine whether the given URL points to a jar file itself, that is, has protocol "file" and ends with the ".jar" extension.
`static boolean`	`isJarURL(URL url)`	Determine whether the given URL points to a resource in a jar file.
`static boolean`	`isUrl(String resourceLocation)`	Return whether the given resource location is a URL: either a special "classpath" pseudo URL or a standard URL.
`static URI`	`toURI(String location)`	Create a URI instance for the given location String, replacing spaces with "%20" URI encoding first.
`static URI`	`toURI(URL url)`	Create a URI instance for the given URL, replacing spaces with "%20" URI encoding first.
`static void`	`useCachesIfNecessary(URLConnection con)`	Set the `"useCaches"` flag on the given connection, preferring `false` but leaving the flag at `true` for JNLP based resources.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - CLASSPATH_URL_PREFIX
```
public static final String CLASSPATH_URL_PREFIX
```
    Pseudo URL prefix for loading from the class path: "classpath:"
    See Also:
    Constant Field Values
  - FILE_URL_PREFIX
```
public static final String FILE_URL_PREFIX
```
    URL prefix for loading from the file system: "file:"
    See Also:
    Constant Field Values
  - JAR_URL_PREFIX
```
public static final String JAR_URL_PREFIX
```
    URL prefix for loading from a jar file: "jar:"
    See Also:
    Constant Field Values
  - WAR_URL_PREFIX
```
public static final String WAR_URL_PREFIX
```
    URL prefix for loading from a war file on Tomcat: "war:"
    See Also:
    Constant Field Values
  - URL_PROTOCOL_FILE
```
public static final String URL_PROTOCOL_FILE
```
    URL protocol for a file in the file system: "file"
    See Also:
    Constant Field Values
  - URL_PROTOCOL_JAR
```
public static final String URL_PROTOCOL_JAR
```
    URL protocol for an entry from a jar file: "jar"
    See Also:
    Constant Field Values
  - URL_PROTOCOL_WAR
```
public static final String URL_PROTOCOL_WAR
```
    URL protocol for an entry from a war file: "war"
    See Also:
    Constant Field Values
  - URL_PROTOCOL_ZIP
```
public static final String URL_PROTOCOL_ZIP
```
    URL protocol for an entry from a zip file: "zip"
    See Also:
    Constant Field Values
  - URL_PROTOCOL_WSJAR
```
public static final String URL_PROTOCOL_WSJAR
```
    URL protocol for an entry from a WebSphere jar file: "wsjar"
    See Also:
    Constant Field Values
  - URL_PROTOCOL_VFSZIP
```
public static final String URL_PROTOCOL_VFSZIP
```
    URL protocol for an entry from a JBoss jar file: "vfszip"
    See Also:
    Constant Field Values
  - URL_PROTOCOL_VFSFILE
```
public static final String URL_PROTOCOL_VFSFILE
```
    URL protocol for a JBoss file system resource: "vfsfile"
    See Also:
    Constant Field Values
  - URL_PROTOCOL_VFS
```
public static final String URL_PROTOCOL_VFS
```
    URL protocol for a general JBoss VFS resource: "vfs"
    See Also:
    Constant Field Values
  - JAR_FILE_EXTENSION
```
public static final String JAR_FILE_EXTENSION
```
    File extension for a regular jar file: ".jar"
    See Also:
    Constant Field Values
  - JAR_URL_SEPARATOR
```
public static final String JAR_URL_SEPARATOR
```
    Separator between JAR URL and file path within the JAR: "!/"
    See Also:
    Constant Field Values
  - WAR_URL_SEPARATOR
```
public static final String WAR_URL_SEPARATOR
```
    Special separator between WAR URL and jar part on Tomcat
    See Also:
    Constant Field Values
- Constructor Detail
  - ResourceUtils
```
public ResourceUtils()
```
- Method Detail
  - isUrl
```
public static boolean isUrl(String resourceLocation)
```
    Return whether the given resource location is a URL: either a special "classpath" pseudo URL or a standard URL.
    Parameters:
    resourceLocation - the location String to check
    Returns:
    whether the location qualifies as a URL
    See Also:
    CLASSPATH_URL_PREFIX, URL
  - getURL
```
public static URL getURL(String resourceLocation)
                  throws FileNotFoundException
```
    Resolve the given resource location to a java.net.URL.
    Does not check whether the URL actually exists; simply returns the URL that the given location would correspond to.
    Parameters:
    resourceLocation - the resource location to resolve: either a "classpath:" pseudo URL, a "file:" URL, or a plain file path
    Returns:
    a corresponding URL object
    Throws:
    FileNotFoundException - if the resource cannot be resolved to a URL
  - getFile
```
public static File getFile(String resourceLocation)
                    throws FileNotFoundException
```
    Resolve the given resource location to a java.io.File, i.e. to a file in the file system.
    Does not check whether the file actually exists; simply returns the File that the given location would correspond to.
    Parameters:
    resourceLocation - the resource location to resolve: either a "classpath:" pseudo URL, a "file:" URL, or a plain file path
    Returns:
    a corresponding File object
    Throws:
    FileNotFoundException - if the resource cannot be resolved to a file in the file system
  - getFile
```
public static File getFile(URL resourceUrl)
                    throws FileNotFoundException
```
    Resolve the given resource URL to a java.io.File, i.e. to a file in the file system.
    Parameters:
    resourceUrl - the resource URL to resolve
    Returns:
    a corresponding File object
    Throws:
    FileNotFoundException - if the URL cannot be resolved to a file in the file system
  - getFile
```
public static File getFile(URL resourceUrl,
                           String description)
                    throws FileNotFoundException
```
    Resolve the given resource URL to a java.io.File, i.e. to a file in the file system.
    Parameters:
    resourceUrl - the resource URL to resolve
    description - a description of the original resource that the URL was created for (for example, a class path location)
    Returns:
    a corresponding File object
    Throws:
    FileNotFoundException - if the URL cannot be resolved to a file in the file system
  - getFile
```
public static File getFile(URI resourceUri)
                    throws FileNotFoundException
```
    Resolve the given resource URI to a java.io.File, i.e. to a file in the file system.
    Parameters:
    resourceUri - the resource URI to resolve
    Returns:
    a corresponding File object
    Throws:
    FileNotFoundException - if the URL cannot be resolved to a file in the file system
    Since:
    2.5
  - getFile
```
public static File getFile(URI resourceUri,
                           String description)
                    throws FileNotFoundException
```
    Resolve the given resource URI to a java.io.File, i.e. to a file in the file system.
    Parameters:
    resourceUri - the resource URI to resolve
    description - a description of the original resource that the URI was created for (for example, a class path location)
    Returns:
    a corresponding File object
    Throws:
    FileNotFoundException - if the URL cannot be resolved to a file in the file system
    Since:
    2.5
  - isFileURL
```
public static boolean isFileURL(URL url)
```
    Determine whether the given URL points to a resource in the file system, i.e. has protocol "file", "vfsfile" or "vfs".
    Parameters:
    url - the URL to check
    Returns:
    whether the URL has been identified as a file system URL
  - isJarURL
```
public static boolean isJarURL(URL url)
```
    Determine whether the given URL points to a resource in a jar file. i.e. has protocol "jar", "war, ""zip", "vfszip" or "wsjar".
    Parameters:
    url - the URL to check
    Returns:
    whether the URL has been identified as a JAR URL
  - isJarFileURL
```
public static boolean isJarFileURL(URL url)
```
    Determine whether the given URL points to a jar file itself, that is, has protocol "file" and ends with the ".jar" extension.
    Parameters:
    url - the URL to check
    Returns:
    whether the URL has been identified as a JAR file URL
    Since:
    4.1
  - extractJarFileURL
```
public static URL extractJarFileURL(URL jarUrl)
                             throws MalformedURLException
```
    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).
    Parameters:
    jarUrl - the original URL
    Returns:
    the URL for the actual jar file
    Throws:
    MalformedURLException - if no valid jar file URL could be extracted
  - extractArchiveURL
```
public static URL extractArchiveURL(URL jarUrl)
                             throws MalformedURLException
```
    Extract the URL for the outermost archive from the given jar/war URL (which may point to a resource in a jar file or to a jar file itself).
    In the case of a jar file nested within a war file, this will return a URL to the war file since that is the one resolvable in the file system.
    Parameters:
    jarUrl - the original URL
    Returns:
    the URL for the actual jar file
    Throws:
    MalformedURLException - if no valid jar file URL could be extracted
    Since:
    4.1.8
    See Also:
    extractJarFileURL(URL)
  - toURI
```
public static URI toURI(URL url)
                 throws URISyntaxException
```
    Create a URI instance for the given URL, replacing spaces with "%20" URI encoding first.
    Parameters:
    url - the URL to convert into a URI instance
    Returns:
    the URI instance
    Throws:
    URISyntaxException - if the URL wasn't a valid URI
    See Also:
    URL.toURI()
  - toURI
```
public static URI toURI(String location)
                 throws URISyntaxException
```
    Create a URI instance for the given location String, replacing spaces with "%20" URI encoding first.
    Parameters:
    location - the location String to convert into a URI instance
    Returns:
    the URI instance
    Throws:
    URISyntaxException - if the location wasn't a valid URI
  - useCachesIfNecessary
```
public static void useCachesIfNecessary(URLConnection con)
```
    Set the "useCaches" flag on the given connection, preferring false but leaving the flag at true for JNLP based resources.
    Parameters:
    con - the URLConnection to set the flag on

Class ResourceUtils

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

CLASSPATH_URL_PREFIX

FILE_URL_PREFIX

JAR_URL_PREFIX

WAR_URL_PREFIX

URL_PROTOCOL_FILE

URL_PROTOCOL_JAR

URL_PROTOCOL_WAR

URL_PROTOCOL_ZIP

URL_PROTOCOL_WSJAR

URL_PROTOCOL_VFSZIP

URL_PROTOCOL_VFSFILE

URL_PROTOCOL_VFS

JAR_FILE_EXTENSION

JAR_URL_SEPARATOR

WAR_URL_SEPARATOR

Constructor Detail

ResourceUtils

Method Detail

isUrl

getURL

getFile

getFile

getFile

getFile

getFile

isFileURL

isJarURL

isJarFileURL

extractJarFileURL

extractArchiveURL

toURI

toURI

useCachesIfNecessary