Package org.springframework.core.io
Class AbstractResource
java.lang.Object
org.springframework.core.io.AbstractResource
- All Implemented Interfaces:
InputStreamSource
,Resource
- Direct Known Subclasses:
AbstractFileResolvingResource
,ByteArrayResource
,DescriptiveResource
,FileSystemResource
,InputStreamResource
,PathResource
,VfsResource
Convenience base class for
Resource
implementations,
pre-implementing typical behavior.
The "exists" method will check whether a File or InputStream can be opened; "isOpen" will always return false; "getURL" and "getFile" throw an exception; and "toString" will return the description.
- Since:
- 28.12.2003
- Author:
- Juergen Hoeller, Sam Brannen
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionlong
This method reads the entire InputStream to determine the content length.createRelative
(String relativePath) This implementation throws a FileNotFoundException, assuming that relative resources cannot be created for this resource.boolean
This implementation compares description strings.boolean
exists()
This implementation checks whether a File can be opened, falling back to whether an InputStream can be opened.getFile()
This implementation throws a FileNotFoundException, assuming that the resource cannot be resolved to an absolute file path.protected File
Determine the File to use for timestamp checking.This implementation always returnsnull
, assuming that this resource type does not have a filename.getURI()
This implementation builds a URI based on the URL returned bygetURL()
.getURL()
This implementation throws a FileNotFoundException, assuming that the resource cannot be resolved to a URL.int
hashCode()
This implementation returns the description's hash code.boolean
isFile()
This implementation always returnsfalse
.boolean
isOpen()
This implementation always returnsfalse
.boolean
This implementation always returnstrue
for a resource thatexists
(revised as of 5.1).long
This implementation checks the timestamp of the underlying File, if available.This implementation returnsChannels.newChannel(InputStream)
with the result ofInputStreamSource.getInputStream()
.toString()
This implementation returns the description of this resource.Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.springframework.core.io.InputStreamSource
getInputStream
Methods inherited from interface org.springframework.core.io.Resource
getContentAsByteArray, getContentAsString, getDescription
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Constructor Details
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AbstractResource
public AbstractResource()
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Method Details
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exists
public boolean exists()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.
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isReadable
public boolean isReadable()This implementation always returnstrue
for a resource thatexists
(revised as of 5.1).- Specified by:
isReadable
in interfaceResource
- See Also:
-
isOpen
public boolean isOpen()This implementation always returnsfalse
. -
isFile
public boolean isFile()This implementation always returnsfalse
. -
getURL
This implementation throws a FileNotFoundException, assuming that the resource cannot be resolved to a URL.- Specified by:
getURL
in interfaceResource
- Throws:
IOException
- if the resource cannot be resolved as URL, i.e. if the resource is not available as a descriptor
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getURI
This implementation builds a URI based on the URL returned bygetURL()
.- Specified by:
getURI
in interfaceResource
- Throws:
IOException
- if the resource cannot be resolved as URI, i.e. if the resource is not available as a descriptor
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getFile
This implementation throws a FileNotFoundException, assuming that the resource cannot be resolved to an absolute file path.- Specified by:
getFile
in interfaceResource
- Throws:
FileNotFoundException
- if the resource cannot be resolved as absolute file path, i.e. if the resource is not available in a file systemIOException
- in case of general resolution/reading failures- See Also:
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readableChannel
This implementation returnsChannels.newChannel(InputStream)
with the result ofInputStreamSource.getInputStream()
.This is the same as in
Resource
's corresponding default method but mirrored here for efficient JVM-level dispatching in a class hierarchy.- Specified by:
readableChannel
in interfaceResource
- Returns:
- the byte channel for the underlying resource (must not be
null
) - Throws:
FileNotFoundException
- if the underlying resource doesn't existIOException
- if the content channel could not be opened- See Also:
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contentLength
This method reads the entire InputStream to determine the content length.For a custom subclass of
InputStreamResource
, we strongly recommend overriding this method with a more optimal implementation, e.g. checking File length, or possibly simply returning -1 if the stream can only be read once.- Specified by:
contentLength
in interfaceResource
- Throws:
IOException
- if the resource cannot be resolved (in the file system or as some other known physical resource type)- See Also:
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lastModified
This implementation checks the timestamp of the underlying File, if available.- Specified by:
lastModified
in interfaceResource
- Throws:
IOException
- if the resource cannot be resolved (in the file system or as some other known physical resource type)- See Also:
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getFileForLastModifiedCheck
Determine the File to use for timestamp checking.The default implementation delegates to
getFile()
.- Returns:
- the File to use for timestamp checking (never
null
) - Throws:
FileNotFoundException
- if the resource cannot be resolved as an absolute file path, i.e. is not available in a file systemIOException
- in case of general resolution/reading failures
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createRelative
This implementation throws a FileNotFoundException, assuming that relative resources cannot be created for this resource.- Specified by:
createRelative
in interfaceResource
- Parameters:
relativePath
- the relative path (relative to this resource)- Returns:
- the resource handle for the relative resource
- Throws:
IOException
- if the relative resource cannot be determined
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getFilename
This implementation always returnsnull
, assuming that this resource type does not have a filename.- Specified by:
getFilename
in interfaceResource
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equals
This implementation compares description strings. -
hashCode
public int hashCode()This implementation returns the description's hash code. -
toString
This implementation returns the description of this resource.
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