Package org.alfresco.repo.content

Class EmptyContentReader

java.lang.Object

org.alfresco.repo.content.AbstractContentAccessor

org.alfresco.repo.content.AbstractContentReader

org.alfresco.repo.content.EmptyContentReader

All Implemented Interfaces:

ContentAccessor, ContentReader

public class EmptyContentReader
extends AbstractContentReader

A blank reader for which exists() always returns false.

Author:

Derek Hulley

Nested Class Summary

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

AbstractContentAccessor.CallbackFileChannel, AbstractContentAccessor.ChannelCloseCallbackAdvise

Constructor Summary

Constructors

Constructor	Description
EmptyContentReader(String contentUrl)

Method Summary

Modifier and Type	Method	Description
protected ContentReader	createReader()	A factory method for subclasses to implement that will ensure the proper implementation of the ContentReader.getReader() method.
boolean	exists()
protected ReadableByteChannel	getDirectReadableChannel()	Provides low-level access to read content from the repository.
long	getLastModified()
long	getSize()

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

addListener, compareContentReaders, getContent, getContent, getContentInputStream, getContentString, getContentString, getFileChannel, getLimits, getReadableChannel, getReader, getTransformerDebug, getUseBufferedInputStream, isChannelOpen, isClosed, setLimits, setTransformerDebug, setUseBufferedInputStream

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

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

Constructor Details

EmptyContentReader

public EmptyContentReader(String contentUrl)

Parameters:

contentUrl - the content URL

Method Details

createReader

protected ContentReader createReader()
                              throws ContentIOException

Description copied from class: AbstractContentReader

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

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

Specified by:

createReader in class AbstractContentReader

Returns:

Returns an instance of the this class

Throws:

ContentIOException

getDirectReadableChannel

protected ReadableByteChannel getDirectReadableChannel()
                                                throws ContentIOException

Description copied from class: AbstractContentReader

Provides low-level access to read content from the repository.

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

Specified by:

getDirectReadableChannel in class AbstractContentReader

Returns:

Returns a channel from which content can be read

Throws:

ContentIOException - if the channel could not be opened or the underlying content has disappeared

exists

public boolean exists()

getLastModified

public long getLastModified()

getSize

public long getSize()