org.springframework.util
Class ResourceUtils

java.lang.Object
  extended by org.springframework.util.ResourceUtils

public abstract class ResourceUtils
extends java.lang.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 to obtain a java.io.File in the file system through its getFile() method.

The main reason for these utility methods for resource location handling is to support Log4jConfigurer, which must be able to resolve resource locations before the logging system has been initialized. Spring' Resource abstraction in the core package, on the other hand, already expects the logging system to be available.

Since:
1.1.5
Author:
Juergen Hoeller
See Also:
Resource, ClassPathResource, FileSystemResource, UrlResource, ResourceLoader

Field Summary
static java.lang.String CLASSPATH_URL_PREFIX
          Pseudo URL prefix for loading from the class path: "classpath:"
static java.lang.String FILE_URL_PREFIX
          URL prefix for loading from the file system: "file:"
static java.lang.String JAR_URL_SEPARATOR
          Separator between JAR URL and file path within the JAR
static java.lang.String URL_PROTOCOL_CODE_SOURCE
          URL protocol for an entry from an OC4J jar file: "code-source"
static java.lang.String URL_PROTOCOL_FILE
          URL protocol for a file in the file system: "file"
static java.lang.String URL_PROTOCOL_JAR
          URL protocol for an entry from a jar file: "jar"
static java.lang.String URL_PROTOCOL_VFSZIP
          URL protocol for an entry from a JBoss jar file: "vfszip"
static java.lang.String URL_PROTOCOL_WSJAR
          URL protocol for an entry from a WebSphere jar file: "wsjar"
static java.lang.String URL_PROTOCOL_ZIP
          URL protocol for an entry from a zip file: "zip"
 
Constructor Summary
ResourceUtils()
           
 
Method Summary
static java.net.URL extractJarFileURL(java.net.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 java.io.File getFile(java.lang.String resourceLocation)
          Resolve the given resource location to a java.io.File, i.e.
static java.io.File getFile(java.net.URI resourceUri)
          Resolve the given resource URI to a java.io.File, i.e.
static java.io.File getFile(java.net.URI resourceUri, java.lang.String description)
          Resolve the given resource URI to a java.io.File, i.e.
static java.io.File getFile(java.net.URL resourceUrl)
          Resolve the given resource URL to a java.io.File, i.e.
static java.io.File getFile(java.net.URL resourceUrl, java.lang.String description)
          Resolve the given resource URL to a java.io.File, i.e.
static java.net.URL getURL(java.lang.String resourceLocation)
          Resolve the given resource location to a java.net.URL.
static boolean isJarURL(java.net.URL url)
          Determine whether the given URL points to a resource in a jar file, that is, has protocol "jar", "zip", "wsjar" or "code-source".
static boolean isUrl(java.lang.String resourceLocation)
          Return whether the given resource location is a URL: either a special "classpath" pseudo URL or a standard URL.
static java.net.URI toURI(java.lang.String location)
          Create a URI instance for the given location String, replacing spaces with "%20" quotes first.
static java.net.URI toURI(java.net.URL url)
          Create a URI instance for the given URL, replacing spaces with "%20" quotes first.
 
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 java.lang.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 java.lang.String FILE_URL_PREFIX
URL prefix for loading from the file system: "file:"

See Also:
Constant Field Values

URL_PROTOCOL_FILE

public static final java.lang.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 java.lang.String URL_PROTOCOL_JAR
URL protocol for an entry from a jar file: "jar"

See Also:
Constant Field Values

URL_PROTOCOL_ZIP

public static final java.lang.String URL_PROTOCOL_ZIP
URL protocol for an entry from a zip file: "zip"

See Also:
Constant Field Values

URL_PROTOCOL_VFSZIP

public static final java.lang.String URL_PROTOCOL_VFSZIP
URL protocol for an entry from a JBoss jar file: "vfszip"

See Also:
Constant Field Values

URL_PROTOCOL_WSJAR

public static final java.lang.String URL_PROTOCOL_WSJAR
URL protocol for an entry from a WebSphere jar file: "wsjar"

See Also:
Constant Field Values

URL_PROTOCOL_CODE_SOURCE

public static final java.lang.String URL_PROTOCOL_CODE_SOURCE
URL protocol for an entry from an OC4J jar file: "code-source"

See Also:
Constant Field Values

JAR_URL_SEPARATOR

public static final java.lang.String JAR_URL_SEPARATOR
Separator between JAR URL and file path within the JAR

See Also:
Constant Field Values
Constructor Detail

ResourceUtils

public ResourceUtils()
Method Detail

isUrl

public static boolean isUrl(java.lang.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 java.net.URL getURL(java.lang.String resourceLocation)
                           throws java.io.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:
java.io.FileNotFoundException - if the resource cannot be resolved to a URL

getFile

public static java.io.File getFile(java.lang.String resourceLocation)
                            throws java.io.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 fil 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:
java.io.FileNotFoundException - if the resource cannot be resolved to a file in the file system

getFile

public static java.io.File getFile(java.net.URL resourceUrl)
                            throws java.io.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:
java.io.FileNotFoundException - if the URL cannot be resolved to a file in the file system

getFile

public static java.io.File getFile(java.net.URL resourceUrl,
                                   java.lang.String description)
                            throws java.io.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:
java.io.FileNotFoundException - if the URL cannot be resolved to a file in the file system

getFile

public static java.io.File getFile(java.net.URI resourceUri)
                            throws java.io.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:
java.io.FileNotFoundException - if the URL cannot be resolved to a file in the file system

getFile

public static java.io.File getFile(java.net.URI resourceUri,
                                   java.lang.String description)
                            throws java.io.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:
java.io.FileNotFoundException - if the URL cannot be resolved to a file in the file system

isJarURL

public static boolean isJarURL(java.net.URL url)
Determine whether the given URL points to a resource in a jar file, that is, has protocol "jar", "zip", "wsjar" or "code-source".

"zip" and "wsjar" are used by BEA WebLogic Server and IBM WebSphere, respectively, but can be treated like jar files. The same applies to "code-source" URLs on Oracle OC4J, provided that the path contains a jar separator.

Parameters:
url - the URL to check
Returns:
whether the URL has been identified as a JAR URL

extractJarFileURL

public static java.net.URL extractJarFileURL(java.net.URL jarUrl)
                                      throws java.net.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:
java.net.MalformedURLException - if no valid jar file URL could be extracted

toURI

public static java.net.URI toURI(java.net.URL url)
                          throws java.net.URISyntaxException
Create a URI instance for the given URL, replacing spaces with "%20" quotes first.

Furthermore, this method works on JDK 1.4 as well, in contrast to the URL.toURI() method.

Parameters:
url - the URL to convert into a URI instance
Returns:
the URI instance
Throws:
java.net.URISyntaxException - if the URL wasn't a valid URI
See Also:
URL.toURI()

toURI

public static java.net.URI toURI(java.lang.String location)
                          throws java.net.URISyntaxException
Create a URI instance for the given location String, replacing spaces with "%20" quotes first.

Parameters:
location - the location String to convert into a URI instance
Returns:
the URI instance
Throws:
java.net.URISyntaxException - if the location wasn't a valid URI