org.springframework.http

Class HttpRangeResource

java.lang.Object

org.springframework.http.HttpRangeResource

All Implemented Interfaces:

InputStreamSource, Resource

public class HttpRangeResource
extends java.lang.Object
implements Resource

Holder that combines a Resource descriptor with HttpRange information to be used for reading selected parts of the resource.

Used as an argument for partial conversion operations in ResourceHttpMessageConverter.

Since:

4.3

Author:

Brian Clozel

See Also:

HttpRange

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.List<HttpRange>	httpRanges
private Resource	resource

Constructor Summary

Constructors

Constructor and Description
HttpRangeResource(java.util.List<HttpRange> httpRanges, Resource resource)

Method Summary

Modifier and Type	Method and Description
long	contentLength() Determine the content length for this resource.
Resource	createRelative(java.lang.String relativePath) Create a resource relative to this resource.
boolean	exists() Return whether this resource actually exists in physical form.
java.lang.String	getDescription() Return a description for this resource, to be used for error output when working with the resource.
java.io.File	getFile() Return a File handle for this resource.
java.lang.String	getFilename() Determine a filename for this resource, i.e.
java.util.List<HttpRange>	getHttpRanges() Return the list of HTTP (byte) ranges describing the requested parts of the Resource, as provided by the HTTP Range request.
java.io.InputStream	getInputStream() Return an InputStream.
java.net.URI	getURI() Return a URI handle for this resource.
java.net.URL	getURL() Return a URL handle for this resource.
boolean	isOpen() Return whether this resource represents a handle with an open stream.
boolean	isReadable() Return whether the contents of this resource can be read, e.g.
long	lastModified() Determine the last-modified timestamp for this resource.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

httpRanges

private final java.util.List<HttpRange> httpRanges

resource

private final Resource resource

Constructor Detail

HttpRangeResource

public HttpRangeResource(java.util.List<HttpRange> httpRanges,
                         Resource resource)

Method Detail

getHttpRanges

public final java.util.List<HttpRange> getHttpRanges()

Return the list of HTTP (byte) ranges describing the requested parts of the Resource, as provided by the HTTP Range request.

exists

public boolean exists()

Description copied from interface: Resource

Return whether this resource actually exists in physical form.

This method performs a definitive existence check, whereas the existence of a Resource handle only guarantees a valid descriptor handle.

Specified by:

exists in interface Resource

isReadable

public boolean isReadable()

Description copied from interface: Resource

Return whether the contents of this resource can be read, e.g. via InputStreamSource.getInputStream() or Resource.getFile().

Will be true for typical resource descriptors; note that actual content reading may still fail when attempted. However, a value of false is a definitive indication that the resource content cannot be read.

Specified by:

isReadable in interface Resource

See Also:

InputStreamSource.getInputStream()

isOpen

public boolean isOpen()

Description copied from interface: Resource

Return whether this resource represents a handle with an open stream. If true, the InputStream cannot be read multiple times, and must be read and closed to avoid resource leaks.

Will be false for typical resource descriptors.

Specified by:

isOpen in interface Resource

getURL

public java.net.URL getURL()
                    throws java.io.IOException

Description copied from interface: Resource

Return a URL handle for this resource.

Specified by:

getURL in interface Resource

Throws:

java.io.IOException - if the resource cannot be resolved as URL, i.e. if the resource is not available as descriptor

getURI

public java.net.URI getURI()
                    throws java.io.IOException

Description copied from interface: Resource

Return a URI handle for this resource.

Specified by:

getURI in interface Resource

Throws:

java.io.IOException - if the resource cannot be resolved as URI, i.e. if the resource is not available as descriptor

getFile

public java.io.File getFile()
                     throws java.io.IOException

Description copied from interface: Resource

Return a File handle for this resource.

Specified by:

getFile in interface Resource

Throws:

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

contentLength

public long contentLength()
                   throws java.io.IOException

Description copied from interface: Resource

Determine the content length for this resource.

Specified by:

contentLength in interface Resource

Throws:

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

lastModified

public long lastModified()
                  throws java.io.IOException

Description copied from interface: Resource

Determine the last-modified timestamp for this resource.

Specified by:

lastModified in interface Resource

Throws:

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

createRelative

public Resource createRelative(java.lang.String relativePath)
                        throws java.io.IOException

Description copied from interface: Resource

Create a resource relative to this resource.

Specified by:

createRelative in interface Resource

Parameters:

relativePath - the relative path (relative to this resource)

Returns:

the resource handle for the relative resource

Throws:

java.io.IOException - if the relative resource cannot be determined

getFilename

public java.lang.String getFilename()

Description copied from interface: Resource

Determine a filename for this resource, i.e. typically the last part of the path: for example, "myfile.txt".

Returns null if this type of resource does not have a filename.

Specified by:

getFilename in interface Resource

getDescription

public java.lang.String getDescription()

Description copied from interface: Resource

Return a description for this resource, to be used for error output when working with the resource.

Implementations are also encouraged to return this value from their toString method.

Specified by:

getDescription in interface Resource

See Also:

Object.toString()

getInputStream

public java.io.InputStream getInputStream()
                                   throws java.io.IOException

Description copied from interface: InputStreamSource

Return an InputStream.

It is expected that each call creates a fresh stream.

This requirement is particularly important when you consider an API such as JavaMail, which needs to be able to read the stream multiple times when creating mail attachments. For such a use case, it is required that each getInputStream() call returns a fresh stream.

Specified by:

getInputStream in interface InputStreamSource

Returns:

the input stream for the underlying resource (must not be null)

Throws:

java.io.IOException - if the stream could not be opened

See Also:

MimeMessageHelper.addAttachment(String, InputStreamSource)