org.alfresco.repo.content
Class AbstractContentWriter

java.lang.Object
  org.alfresco.repo.content.AbstractContentAccessor
      org.alfresco.repo.content.AbstractContentWriter

All Implemented Interfaces:

ContentAccessor, ContentWriter

Direct Known Subclasses:

FileContentWriter

public abstract class AbstractContentWriter
extends AbstractContentAccessor
implements ContentWriter

Implements all the convenience methods of the interface. The only methods that need to be implemented, i.e. provide low-level content access are:

• AbstractContentWriter.getReader() to create a reader to the underlying content
• AbstractContentWriter.getDirectWritableChannel() to write content to the repository

Nested Class Summary

Nested classes/interfaces inherited from class org.alfresco.repo.content.AbstractContentAccessor

AbstractContentAccessor.CallbackFileChannel, AbstractContentAccessor.ChannelCloseCallbackAdvise

Constructor Summary

protected

AbstractContentWriter(java.lang.String contentUrl, ContentReader existingContentReader)

Method Summary

void	addListener(ContentStreamListener listener) Adds the listener after checking that the output stream isn't already in use.
protected abstract ContentReader	createReader() A factory method for subclasses to implement that will ensure the proper implementation of the ContentWriter.getReader() method.
java.io.OutputStream	getContentOutputStream() Get a stream to write to the underlying channel.
protected abstract java.nio.channels.WritableByteChannel	getDirectWritableChannel() Provides low-level access to write content to the repository.
protected ContentReader	getExistingContentReader()
java.nio.channels.FileChannel	getFileChannel(boolean truncate) Provides read-write, random-access to the underlying content.
ContentReader	getReader() Performs checks and copies required reader attributes
java.nio.channels.WritableByteChannel	getWritableChannel() Provides low-level access to write to repository content.
boolean	isChannelOpen() Gets the open/close state of the underlying IO Channel.
boolean	isClosed() An automatically created listener sets the flag
void	putContent(ContentReader reader) Copies content from the reader.
void	putContent(java.io.File file) Puts content to the repository direct from file
void	putContent(java.io.InputStream is) Puts content to the repository
void	putContent(java.lang.String content) Makes use of the encoding, if available, to convert the string to bytes.

Methods inherited from class org.alfresco.repo.content.AbstractContentAccessor

channelOpened, finalize, getCallbackFileChannel, getContentData, getContentUrl, getEncoding, getLocale, getMimetype, setContentUrl, setEncoding, setLocale, setMimetype, setRetryingTransactionHelper, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.alfresco.service.cmr.repository.ContentAccessor

getContentData, getContentUrl, getEncoding, getLocale, getMimetype, getSize, setEncoding, setLocale, setMimetype, setRetryingTransactionHelper

Constructor Detail

AbstractContentWriter

protected AbstractContentWriter(java.lang.String contentUrl,
                                ContentReader existingContentReader)

Parameters:

contentUrl - the content URL

existingContentReader - a reader of a previous version of this content

Method Detail

getExistingContentReader

protected ContentReader getExistingContentReader()

Returns:

Returns a reader onto the previous version of this content

addListener

public void addListener(ContentStreamListener listener)

Adds the listener after checking that the output stream isn't already in use.

Specified by:

addListener in interface ContentAccessor

Parameters:

listener - a listener that will be called for output stream event notification

See Also:

ContentAccessor.setRetryingTransactionHelper(RetryingTransactionHelper)

createReader

protected abstract ContentReader createReader()
                                       throws ContentIOException

A factory method for subclasses to implement that will ensure the proper implementation of the ContentWriter.getReader() method.

Only the instance need be constructed. The required mimetype, encoding, etc will be copied across by this class.

Returns:

Returns a reader onto the location referenced by this instance. The instance must always be a new instance and never null.

Throws:

ContentIOException

getReader

public final ContentReader getReader()
                              throws ContentIOException

Performs checks and copies required reader attributes

Specified by:

getReader in interface ContentWriter

Returns:

Returns a reader onto the underlying content that this writer will or has written to

Throws:

ContentIOException

isClosed

public final boolean isClosed()

An automatically created listener sets the flag

Specified by:

isClosed in interface ContentWriter

Returns:

Return true if the content output stream has been used and closed otherwise false.

isChannelOpen

public boolean isChannelOpen()

Description copied from interface: ContentAccessor

Gets the open/close state of the underlying IO Channel.

Specified by:

isChannelOpen in interface ContentAccessor

Returns:

Returns true if the underlying IO Channel is open

getDirectWritableChannel

protected abstract java.nio.channels.WritableByteChannel getDirectWritableChannel()
                                                                           throws ContentIOException

Provides low-level access to write content to the repository.

This is the only of the content writing methods that needs to be implemented by derived classes. All other content access methods make use of this in their underlying implementations.

Returns:

Returns a channel with which to write content

Throws:

ContentIOException - if the channel could not be opened

getWritableChannel

public final java.nio.channels.WritableByteChannel getWritableChannel()
                                                               throws ContentIOException

Description copied from interface: ContentWriter

Provides low-level access to write to repository content.

The channel returned to the client should remain open (subject to timeouts) until closed by the client. All lock detection, read-only access and other concurrency issues are dealt with during this operation. It remains possible that implementations will throw exceptions when the channel is closed.

The stream will notify any listeners according to the listener interface.

Specified by:

getWritableChannel in interface ContentWriter

Returns:

Returns a channel with which to write content

Throws:

ContentIOException

See Also:

AbstractContentWriter.getDirectWritableChannel(), #getCallbackWritableChannel()

getFileChannel

public java.nio.channels.FileChannel getFileChannel(boolean truncate)
                                             throws ContentIOException

Provides read-write, random-access to the underlying content. In general, this method should be considered more expensive than the sequential-access method, ContentWriter.getWritableChannel().

Underlying implementations use the truncate parameter to determine the most effective means of providing access to the content.

Specified by:

getFileChannel in interface ContentWriter

Parameters:

truncate - true to start with zero length content

Returns:

Returns a random-access channel onto the content

Throws:

ContentIOException

See Also:

ContentWriter.getWritableChannel(), RandomAccessFile.getChannel()

getContentOutputStream

public java.io.OutputStream getContentOutputStream()
                                            throws ContentIOException

Description copied from interface: ContentWriter

Get a stream to write to the underlying channel.

Specified by:

getContentOutputStream in interface ContentWriter

Returns:

Returns an output stream onto the underlying channel

Throws:

ContentIOException

See Also:

Channels.newOutputStream(java.nio.channels.WritableByteChannel)

putContent

public void putContent(ContentReader reader)
                throws ContentIOException

Description copied from interface: ContentWriter

Copies content from the reader.

All resources will be closed automatically.

Specified by:

putContent in interface ContentWriter

Parameters:

reader - the reader acting as the source of the content

Throws:

ContentIOException

See Also:

ContentReader.getContentInputStream(), AbstractContentWriter.putContent(InputStream)

putContent

public final void putContent(java.io.InputStream is)
                      throws ContentIOException

Description copied from interface: ContentWriter

Puts content to the repository

All resources will be closed automatically.

Specified by:

putContent in interface ContentWriter

Parameters:

is - the input stream from which the content will be read

Throws:

ContentIOException

See Also:

ContentWriter.getWritableChannel()

putContent

public final void putContent(java.io.File file)
                      throws ContentIOException

Description copied from interface: ContentWriter

Puts content to the repository direct from file

All resources will be closed automatically.

Specified by:

putContent in interface ContentWriter

Parameters:

file - the file to load the content from

Throws:

ContentIOException

See Also:

ContentWriter.getWritableChannel()

putContent

public final void putContent(java.lang.String content)
                      throws ContentIOException

Makes use of the encoding, if available, to convert the string to bytes.

Specified by:

putContent in interface ContentWriter

Parameters:

content - a string representation of the content

Throws:

ContentIOException

See Also:

ContentAccessor.getEncoding()