org.dspace.content

Class Bitstream

java.lang.Object

org.dspace.content.DSpaceObject

org.dspace.content.Bitstream

public class Bitstream
extends DSpaceObject

Class representing bitstreams stored in the DSpace system.

When modifying the bitstream metadata, changes are not reflected in the database until update is called. Note that you cannot alter the contents of a bitstream; you need to create a new bitstream.

Version:

$Revision$

Author:

Robert Tansley

Method Summary

Methods

Modifier and Type	Method and Description
static Bitstream	find(Context context, int id) Get a bitstream from the database.
static Bitstream[]	findAll(Context context)
Bundle[]	getBundles() Get the bundles this bitstream appears in
java.lang.String	getChecksum() Get the checksum of the content of the bitstream, for integrity checking
java.lang.String	getChecksumAlgorithm() Get the algorithm used to calculate the checksum
java.lang.String	getDescription() Get the description of this bitstream - optional free text, typically provided by a user at submission time
BitstreamFormat	getFormat() Get the format of the bitstream
java.lang.String	getFormatDescription() Get the description of the format - either the user's or the description of the format defined by the system.
java.lang.String	getHandle() Get the Handle of the object.
int	getID() Get the internal identifier of this bitstream
java.lang.String	getName() Get the name of this bitstream - typically the filename, without any path information
DSpaceObject	getParentObject() Get the parent object of a bitstream.
int	getSequenceID() Get the sequence ID of this bitstream
long	getSize() Get the size of the bitstream
java.lang.String	getSource() Get the source of this bitstream - typically the filename with path information (if originally provided) or the name of the tool that generated this bitstream
int	getStoreNumber() Get the asset store number where this bitstream is stored
int	getType() return type found in Constants
java.lang.String	getUserFormatDescription() Get the user's format description.
boolean	isRegisteredBitstream() Determine if this bitstream is registered (available elsewhere on filesystem than in assetstore).
java.io.InputStream	retrieve() Retrieve the contents of the bitstream
void	setDescription(java.lang.String n) Set the description of the bitstream
void	setFormat(BitstreamFormat f) Set the format of the bitstream.
void	setName(java.lang.String n) Set the name of the bitstream
void	setSequenceID(int sid) Set the sequence ID of this bitstream
void	setSource(java.lang.String n) Set the source of the bitstream
void	setUserFormatDescription(java.lang.String desc) Set the user's format description.
void	update() Update the bitstream metadata.
void	updateLastModified()

Methods inherited from class org.dspace.content.DSpaceObject

addDetails, clearDetails, find, getAdminObject, getDetails, getTypeText

Methods inherited from class java.lang.Object

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

Method Detail

find

public static Bitstream find(Context context,
             int id)
                      throws java.sql.SQLException

Get a bitstream from the database. The bitstream metadata is loaded into memory.

Parameters:

context - DSpace context object

id - ID of the bitstream

Returns:

the bitstream, or null if the ID is invalid.

Throws:

java.sql.SQLException

findAll

public static Bitstream[] findAll(Context context)
                           throws java.sql.SQLException

Throws:

java.sql.SQLException

getID

public int getID()

Get the internal identifier of this bitstream

Specified by:

getID in class DSpaceObject

Returns:

the internal identifier

getHandle

public java.lang.String getHandle()

Description copied from class: DSpaceObject

Get the Handle of the object. This may return null

Specified by:

getHandle in class DSpaceObject

Returns:

Handle of the object, or null if it doesn't have one

getSequenceID

public int getSequenceID()

Get the sequence ID of this bitstream

Returns:

the sequence ID

setSequenceID

public void setSequenceID(int sid)

Set the sequence ID of this bitstream

Parameters:

sid - the ID

getName

public java.lang.String getName()

Get the name of this bitstream - typically the filename, without any path information

Specified by:

getName in class DSpaceObject

Returns:

the name of the bitstream

setName

public void setName(java.lang.String n)

Set the name of the bitstream

Parameters:

n - the new name of the bitstream

getSource

public java.lang.String getSource()

Get the source of this bitstream - typically the filename with path information (if originally provided) or the name of the tool that generated this bitstream

Returns:

the source of the bitstream

setSource

public void setSource(java.lang.String n)

Set the source of the bitstream

Parameters:

n - the new source of the bitstream

getDescription

public java.lang.String getDescription()

Get the description of this bitstream - optional free text, typically provided by a user at submission time

Returns:

the description of the bitstream

setDescription

public void setDescription(java.lang.String n)

Set the description of the bitstream

Parameters:

n - the new description of the bitstream

getChecksum

public java.lang.String getChecksum()

Get the checksum of the content of the bitstream, for integrity checking

Returns:

the checksum

getChecksumAlgorithm

public java.lang.String getChecksumAlgorithm()

Get the algorithm used to calculate the checksum

Returns:

the algorithm, e.g. "MD5"

getSize

public long getSize()

Get the size of the bitstream

Returns:

the size in bytes

setUserFormatDescription

public void setUserFormatDescription(java.lang.String desc)
                              throws java.sql.SQLException

Set the user's format description. This implies that the format of the bitstream is uncertain, and the format is set to "unknown."

Parameters:

desc - the user's description of the format

Throws:

java.sql.SQLException

getUserFormatDescription

public java.lang.String getUserFormatDescription()

Get the user's format description. Returns null if the format is known by the system.

Returns:

the user's format description.

getFormatDescription

public java.lang.String getFormatDescription()

Get the description of the format - either the user's or the description of the format defined by the system.

Returns:

a description of the format.

getFormat

public BitstreamFormat getFormat()

Get the format of the bitstream

Returns:

the format of this bitstream

setFormat

public void setFormat(BitstreamFormat f)
               throws java.sql.SQLException

Set the format of the bitstream. If the user has supplied a type description, it is cleared. Passing in null sets the type of this bitstream to "unknown".

Parameters:

f - the format of this bitstream, or null for unknown

Throws:

java.sql.SQLException

update

public void update()
            throws java.sql.SQLException,
                   AuthorizeException

Update the bitstream metadata. Note that the content of the bitstream cannot be changed - for that you need to create a new bitstream.

Specified by:

update in class DSpaceObject

Throws:

java.sql.SQLException

AuthorizeException

retrieve

public java.io.InputStream retrieve()
                             throws java.io.IOException,
                                    java.sql.SQLException,
                                    AuthorizeException

Retrieve the contents of the bitstream

Returns:

a stream from which the bitstream can be read.

Throws:

java.io.IOException

java.sql.SQLException

AuthorizeException

getBundles

public Bundle[] getBundles()
                    throws java.sql.SQLException

Get the bundles this bitstream appears in

Returns:

array of Bundle s this bitstream appears in

Throws:

java.sql.SQLException

getType

public int getType()

return type found in Constants

Specified by:

getType in class DSpaceObject

Returns:

int Constants.BITSTREAM

isRegisteredBitstream

public boolean isRegisteredBitstream()

Determine if this bitstream is registered (available elsewhere on filesystem than in assetstore). More about registered items: https://wiki.duraspace.org/display/DSDOC3x/Registering+(not+Importing)+Bitstreams+via+Simple+Archive+Format

Returns:

true if the bitstream is registered, false otherwise

getStoreNumber

public int getStoreNumber()

Get the asset store number where this bitstream is stored

Returns:

the asset store number of the bitstream

getParentObject

public DSpaceObject getParentObject()
                             throws java.sql.SQLException

Get the parent object of a bitstream. The parent can be an item if this is a normal bitstream, or it could be a collection or a community if the bitstream is a logo.

Overrides:

getParentObject in class DSpaceObject

Returns:

this bitstream's parent.

Throws:

java.sql.SQLException

updateLastModified

public void updateLastModified()

Specified by:

updateLastModified in class DSpaceObject