oracle.ifs.server

Class PostgresMediaBlobHelper

java.lang.Object

oracle.ifs.server.MediaBlobHelper

oracle.ifs.server.PostgresMediaBlobHelper

public class PostgresMediaBlobHelper
extends MediaBlobHelper

An PostgresMediaBlobHelper is a Postgres implementation of MediaBlobHelper, handling Blob operations for an S_MediaBlob instance.

(Published)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PostgresMediaBlobHelper.LargeObjectProxy LargeObjectProxy is a proxy for LargeObject, used so that the availability of the LargeObject can be managed to avoid SQL failures on the LibraryConnection from which the LargeObject was obtained.

Field Summary

Fields inherited from class oracle.ifs.server.MediaBlobHelper

m_MediaBlob, m_Session

Constructor Summary

Constructors

Constructor and Description
PostgresMediaBlobHelper(S_MediaBlob mediaBlob) Constructs an PostgresMediaBlobHelper instance.

Method Summary

Modifier and Type	Method and Description
protected void	copyContent(S_MediaBfile srcMedia, Long srcCid, Long dstCid, Long partitionValue, AttributeValue[] mediaOptions) Stores a copy of existing content as the content for the specified content id, with a S_MediaBfile being the source.
protected void	copyContent(S_MediaBlob srcMedia, Long srcCid, Long dstCid, Long partitionValue, AttributeValue[] mediaOptions) Stores a copy of existing content as the content for the specified content id, with a S_MediaBlob being the source.
void	createContentIndexProcedure(Connection conn) Recreates the content index procedure, if any, for this MediaBlob instance.
protected void	destroyContent(Long cid, AttributeValue[] mediaOptions) Destroys the content for the specified content ID.
protected InputStream	getContent(Long cid) Gets the content stream for the specified content id.
protected long	getContentSize(Long cid) Gets the size of the content stream for the specified content id.
protected PostgresMediaBlobHelper.LargeObjectProxy	getLargeObject(Long cid) Gets the LargeObject for the specified content id.
protected RandomAccessDriver	getRandomAccessDriver(Long cid) Returns a RandomAccessDriver to use to retrieve the indicated content.
protected void	setContent(Long cid, InputStream is, Long partitionValue, AttributeValue[] mediaOptions) Stores content read from the specified InputStream using the specified content id.
protected void	setEmptyContent(Long cid, Long partitionValue, AttributeValue[] mediaOptions) Stores zero-length content for the specified content id.

Methods inherited from class oracle.ifs.server.MediaBlobHelper

getSession

Methods inherited from class java.lang.Object

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

Constructor Detail

PostgresMediaBlobHelper

public PostgresMediaBlobHelper(S_MediaBlob mediaBlob)
                        throws IfsException

Constructs an PostgresMediaBlobHelper instance.

Parameters:

mediaBlob - the S_MediaBlob instance being serviced

Throws:

IfsException - if the operation fails

(Published)

Method Detail

createContentIndexProcedure

public void createContentIndexProcedure(Connection conn)
                                 throws IfsException

Recreates the content index procedure, if any, for this MediaBlob instance.

Specified by:

createContentIndexProcedure in class MediaBlobHelper

Parameters:

conn - the connection

Throws:

IfsException - if the operation fails

(Unpublished)

getContent

protected InputStream getContent(Long cid)
                          throws IfsException

Gets the content stream for the specified content id.

Specified by:

getContent in class MediaBlobHelper

Parameters:

cid - the content id; required

Returns:

the content stream; non-null

Throws:

IfsException - if the operation fails

getLargeObject

protected PostgresMediaBlobHelper.LargeObjectProxy getLargeObject(Long cid)
                                                           throws IfsException

Gets the LargeObject for the specified content id.

Not part of the interface, but closely related to getContent.

Parameters:

cid - the content ID

Returns:

the LargeObject

Throws:

IfsException - if the operation fails

(Unpublished)

getContentSize

protected long getContentSize(Long cid)
                       throws IfsException

Gets the size of the content stream for the specified content id.

Specified by:

getContentSize in class MediaBlobHelper

Parameters:

cid - the content id; required

Returns:

the size, in bytes

Throws:

IfsException - if the operation fails

setContent

protected void setContent(Long cid,
                          InputStream is,
                          Long partitionValue,
                          AttributeValue[] mediaOptions)
                   throws IfsException

Stores content read from the specified InputStream using the specified content id.

The implementation of this method is responsible for inserting a row into the content table whose ID column is cid, storing content read from the InputStream, and closing the InputStream.

Specified by:

setContent in class MediaBlobHelper

Parameters:

cid - the content id; required

is - the InputStream from which content is read

partitionValue - the value for the PARTITIONVALUE column in the content table, or null if none

mediaOptions - a set of name/value pairs whose semantics are Media determined, or null for no media options

Throws:

IfsException - if the operation fails

setEmptyContent

protected void setEmptyContent(Long cid,
                               Long partitionValue,
                               AttributeValue[] mediaOptions)
                        throws IfsException

Stores zero-length content for the specified content id.

The implementation of this method is responsible for inserting a row into the content table whose ID column is cid.

Althrough a concrete implementation is provided here (by calling setContent and immediately closing the returned OutputStream), subclasses should override this method with a more performant implementation, if possible.

Specified by:

setEmptyContent in class MediaBlobHelper

Parameters:

cid - the content id; required

partitionValue - the value for the PARTITIONVALUE column in the content table, or null if none

mediaOptions - a set of name/value pairs whose semantics are Media determined, or null for no media options

Throws:

IfsException - if the operation fails

copyContent

protected void copyContent(S_MediaBlob srcMedia,
                           Long srcCid,
                           Long dstCid,
                           Long partitionValue,
                           AttributeValue[] mediaOptions)
                    throws IfsException

Stores a copy of existing content as the content for the specified content id, with a S_MediaBlob being the source.

The implementation of this method is responsible for inserting a row into the content table whose ID column is dstCid.

Although a concrete implementation is provided here (by copying the InputStream returned by srcMedia.getContent(srcCid) to the OutputStream returned by setContent), subclasses should override this method with a more performant implementation, if possible.

Specified by:

copyContent in class MediaBlobHelper

Parameters:

srcMedia - the S_MediaBlob source media; required

srcCid - the source content id; required

dstCid - the destination content id; required

partitionValue - the value for the PARTITIONVALUE column in the content table, or null if none

mediaOptions - a set of name/value pairs whose semantics are Media determined, or null for no media options

Throws:

IfsException - if the operation fails

copyContent

protected void copyContent(S_MediaBfile srcMedia,
                           Long srcCid,
                           Long dstCid,
                           Long partitionValue,
                           AttributeValue[] mediaOptions)
                    throws IfsException

Stores a copy of existing content as the content for the specified content id, with a S_MediaBfile being the source.

The implementation of this method is responsible for inserting a row into the content table whose ID column is dstCid.

Although a concrete implementation is provided here (by copying the InputStream returned by srcMedia.getContent(srcCid) to the OutputStream returned by setContent), subclasses should override this method with a more performant implementation, if possible.

Specified by:

copyContent in class MediaBlobHelper

Parameters:

srcMedia - the S_MediaBfile source media; required

srcCid - the source content id; required

dstCid - the destination content id; required

partitionValue - the value for the PARTITIONVALUE column in the content table, or null if none

mediaOptions - a set of name/value pairs whose semantics are Media determined, or null for no media options

Throws:

IfsException - if the operation fails

destroyContent

protected void destroyContent(Long cid,
                              AttributeValue[] mediaOptions)
                       throws IfsException

Destroys the content for the specified content ID.

Specified by:

destroyContent in class MediaBlobHelper

Parameters:

cid - the content id; required

mediaOptions - a set of name/value pairs whose semantics are Media determined, or null for no media options

Throws:

IfsException - if the operation fails

getRandomAccessDriver

protected RandomAccessDriver getRandomAccessDriver(Long cid)
                                            throws IfsException

Returns a RandomAccessDriver to use to retrieve the indicated content.

Specified by:

getRandomAccessDriver in class MediaBlobHelper

Parameters:

cid - the content id; required

Returns:

the RandomAccessDriver

Throws:

IfsException - if the operation fails