spark.resource

Class AbstractFileResolvingResource

java.lang.Object

spark.resource.AbstractResource

spark.resource.AbstractFileResolvingResource

All Implemented Interfaces:

InputStreamResource, Resource

Direct Known Subclasses:

ClassPathResource, ExternalResource

public abstract class AbstractFileResolvingResource
extends AbstractResource

Abstract base class for resources which resolve URLs into File references, such as UrlResource or ClassPathResource.

Detects the "file" protocol as well as the JBoss "vfs" protocol in URLs, resolving file system references accordingly.

Author:

Juergen Hoeller Code copied from Spring source. Modifications made (mostly removal of methods) by Per Wendel.

Constructor Summary

Constructors

Constructor and Description
AbstractFileResolvingResource()

Method Summary

Modifier and Type	Method and Description
long	contentLength() This implementation reads the entire InputStream to calculate the content length.
protected void	customizeConnection(HttpURLConnection con) Customize the given HttpURLConnection, obtained in the course of an exists(), contentLength() or lastModified() call.
protected void	customizeConnection(URLConnection con) Customize the given URLConnection, obtained in the course of an exists(), contentLength() or lastModified() call.
boolean	exists() This implementation checks whether a File can be opened, falling back to whether an InputStream can be opened.
File	getFile() This implementation returns a File reference for the underlying class path resource, provided that it refers to a file in the file system.
protected File	getFileForLastModifiedCheck() This implementation determines the underlying File (or jar file, in case of a resource in a jar/zip).
boolean	isReadable() This implementation always returns true.
long	lastModified() This implementation checks the timestamp of the underlying File, if available.

Methods inherited from class spark.resource.AbstractResource

createRelative, equals, getFilename, getURI, getURL, hashCode, isOpen, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface spark.resource.Resource

getDescription

Methods inherited from interface spark.resource.InputStreamResource

getInputStream

Constructor Detail

AbstractFileResolvingResource

public AbstractFileResolvingResource()

Method Detail

getFile

public File getFile()
             throws IOException

This implementation returns a File reference for the underlying class path resource, provided that it refers to a file in the file system.

Specified by:

getFile in interface Resource

Overrides:

getFile in class AbstractResource

Returns:

a File handle for this resource.

Throws:

IOException - if the resource cannot be resolved as absolute file path, i.e. if the resource is not available in a file system

getFileForLastModifiedCheck

protected File getFileForLastModifiedCheck()
                                    throws IOException

This implementation determines the underlying File (or jar file, in case of a resource in a jar/zip).

Overrides:

getFileForLastModifiedCheck in class AbstractResource

Returns:

the File to use for timestamp checking (never null)

Throws:

IOException - if the resource cannot be resolved as absolute file path, i.e. if the resource is not available in a file system

exists

public boolean exists()

Description copied from class: AbstractResource

This implementation checks whether a File can be opened, falling back to whether an InputStream can be opened. This will cover both directories and content resources.

Specified by:

exists in interface Resource

Overrides:

exists in class AbstractResource

Returns:

if exists

isReadable

public boolean isReadable()

Description copied from class: AbstractResource

This implementation always returns true.

Specified by:

isReadable in interface Resource

Overrides:

isReadable in class AbstractResource

Returns:

if readable

See Also:

InputStreamResource.getInputStream()

contentLength

public long contentLength()
                   throws IOException

Description copied from class: AbstractResource

This implementation reads the entire InputStream to calculate the content length. Subclasses will almost always be able to provide a more optimal version of this, e.g. checking a File length.

Specified by:

contentLength in interface Resource

Overrides:

contentLength in class AbstractResource

Returns:

the content length for this resource.

Throws:

IOException - if the resource cannot be resolved (in the file system or as some other known physical resource type)

See Also:

InputStreamResource.getInputStream()

lastModified

public long lastModified()
                  throws IOException

Description copied from class: AbstractResource

This implementation checks the timestamp of the underlying File, if available.

Specified by:

lastModified in interface Resource

Overrides:

lastModified in class AbstractResource

Returns:

the last-modified timestamp for this resource.

Throws:

IOException - if the resource cannot be resolved (in the file system or as some other known physical resource type)

See Also:

AbstractResource.getFileForLastModifiedCheck()

customizeConnection

protected void customizeConnection(URLConnection con)
                            throws IOException

Customize the given URLConnection, obtained in the course of an exists(), contentLength() or lastModified() call.

Calls ResourceUtils.useCachesIfNecessary(URLConnection) and delegates to customizeConnection(HttpURLConnection) if possible. Can be overridden in subclasses.

Parameters:

con - the URLConnection to customize

Throws:

IOException - if thrown from URLConnection methods

customizeConnection

protected void customizeConnection(HttpURLConnection con)
                            throws IOException

Customize the given HttpURLConnection, obtained in the course of an exists(), contentLength() or lastModified() call.

Sets request method "HEAD" by default. Can be overridden in subclasses.

Parameters:

con - the HttpURLConnection to customize

Throws:

IOException - if thrown from HttpURLConnection methods