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

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
String	getChecksum() Get the checksum of the content of the bitstream, for integrity checking
String	getChecksumAlgorithm() Get the algorithm used to calculate the checksum
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
String	getFormatDescription() Get the description of the format - either the user's or the description of the format defined by the system.
String	getHandle() Get the Handle of the object.
int	getID() Get the internal identifier of this bitstream
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
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
String	getUserFormatDescription() Get the user's format description.
boolean	isRegisteredBitstream() Determine if this bitstream is registered
InputStream	retrieve() Retrieve the contents of the bitstream
void	setDescription(String n) Set the description of the bitstream
void	setFormat(BitstreamFormat f) Set the format of the bitstream.
void	setName(String n) Set the name of the bitstream
void	setSequenceID(int sid) Set the sequence ID of this bitstream
void	setSource(String n) Set the source of the bitstream
void	setUserFormatDescription(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 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:

SQLException

findAll

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

Throws:

SQLException

getID

public int getID()

Get the internal identifier of this bitstream

Specified by:

getID in class DSpaceObject

Returns:

the internal identifier

getHandle

public 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 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(String n)

Set the name of the bitstream

Parameters:

n - the new name of the bitstream

getSource

public 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(String n)

Set the source of the bitstream

Parameters:

n - the new source of the bitstream

getDescription

public 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(String n)

Set the description of the bitstream

Parameters:

n - the new description of the bitstream

getChecksum

public String getChecksum()

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

Returns:

the checksum

getChecksumAlgorithm

public 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(String desc)
                              throws 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:

SQLException

getUserFormatDescription

public 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 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 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:

SQLException

update

public void update()
            throws 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:

SQLException

AuthorizeException

retrieve

public InputStream retrieve()
                     throws IOException,
                            SQLException,
                            AuthorizeException

Retrieve the contents of the bitstream

Returns:

a stream from which the bitstream can be read.

Throws:

IOException

SQLException

AuthorizeException

getBundles

public Bundle[] getBundles()
                    throws SQLException

Get the bundles this bitstream appears in

Returns:

array of Bundle s this bitstream appears in

Throws:

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

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 SQLException

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

Overrides:

getParentObject in class DSpaceObject

Returns:

Throws:

SQLException

updateLastModified

public void updateLastModified()

Specified by:

updateLastModified in class DSpaceObject