org.alfresco.repo.content

Class AbstractContentReader

java.lang.Object

org.alfresco.repo.content.AbstractContentAccessor

org.alfresco.repo.content.AbstractContentReader

All Implemented Interfaces:

ContentAccessor, ContentReader

Direct Known Subclasses:

EmptyContentReader, FileContentReader, HttpAlfrescoContentReader, SpoofedTextContentReader

@AlfrescoPublicApi
public abstract class AbstractContentReader
extends AbstractContentAccessor
implements ContentReader

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

• createReader() to read content from the repository
• getDirectReadableChannel() to provide direct storage access

Author:

Derek Hulley

Nested Class Summary

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

AbstractContentAccessor.CallbackFileChannel, AbstractContentAccessor.ChannelCloseCallbackAdvise

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractContentReader(String contentUrl)

Method Summary

Modifier and Type	Method and Description
void	addListener(ContentStreamListener listener) Adds the listener after checking that the output stream isn't already in use.
static boolean	compareContentReaders(ContentReader left, ContentReader right) Does a comparison of the binaries associated with two readers.
protected abstract ContentReader	createReader() A factory method for subclasses to implement that will ensure the proper implementation of the ContentReader.getReader() method.
void	getContent(File file)
void	getContent(OutputStream os) Copies the input stream to the given OutputStream
InputStream	getContentInputStream()
String	getContentString() Makes use of the encoding, if available, to convert bytes to a string.
String	getContentString(int length)
protected abstract ReadableByteChannel	getDirectReadableChannel() Provides low-level access to read content from the repository.
FileChannel	getFileChannel()
TransformationOptionLimits	getLimits()
ReadableByteChannel	getReadableChannel()
ContentReader	getReader() Performs checks and copies required reader attributes
TransformerDebug	getTransformerDebug()
boolean	getUseBufferedInputStream()
boolean	isChannelOpen()
boolean	isClosed() An automatically created listener sets the flag
void	setLimits(TransformationOptionLimits limits)
void	setTransformerDebug(TransformerDebug transformerDebug)
void	setUseBufferedInputStream(boolean useBufferedInputStream)

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.ContentReader

exists, getLastModified

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

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

Constructor Detail

AbstractContentReader

protected AbstractContentReader(String contentUrl)

Parameters:

contentUrl - the content URL - this should be relative to the root of the store and not absolute: to enable moving of the stores

Method Detail

setLimits

public void setLimits(TransformationOptionLimits limits)

getLimits

public TransformationOptionLimits getLimits()

setTransformerDebug

public void setTransformerDebug(TransformerDebug transformerDebug)

getTransformerDebug

public TransformerDebug getTransformerDebug()

setUseBufferedInputStream

public void setUseBufferedInputStream(boolean useBufferedInputStream)

getUseBufferedInputStream

public boolean getUseBufferedInputStream()

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

createReader

protected abstract ContentReader createReader()
                                       throws ContentIOException

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.

Returns:

Returns a reader onto the location referenced by this instance. The instance must always be a new instance.

Throws:

ContentIOException

getReader

public final ContentReader getReader()
                              throws ContentIOException

Performs checks and copies required reader attributes

Specified by:

getReader in interface ContentReader

Throws:

ContentIOException

isClosed

public final boolean isClosed()

An automatically created listener sets the flag

Specified by:

isClosed in interface ContentReader

isChannelOpen

public boolean isChannelOpen()

Specified by:

isChannelOpen in interface ContentAccessor

getDirectReadableChannel

protected abstract ReadableByteChannel getDirectReadableChannel()
                                                         throws ContentIOException

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.

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

getReadableChannel

public final ReadableByteChannel getReadableChannel()
                                             throws ContentIOException

Specified by:

getReadableChannel in interface ContentReader

Throws:

ContentIOException

See Also:

getDirectReadableChannel(), getCallbackReadableChannel(ReadableByteChannel, List)

getFileChannel

public FileChannel getFileChannel()
                           throws ContentIOException

Specified by:

getFileChannel in interface ContentReader

Throws:

ContentIOException

getContentInputStream

public InputStream getContentInputStream()
                                  throws ContentIOException

Specified by:

getContentInputStream in interface ContentReader

Throws:

ContentIOException

See Also:

Channels.newInputStream(java.nio.channels.ReadableByteChannel)

getContent

public final void getContent(OutputStream os)
                      throws ContentIOException

Copies the input stream to the given OutputStream

Specified by:

getContent in interface ContentReader

Throws:

ContentIOException

getContent

public final void getContent(File file)
                      throws ContentIOException

Specified by:

getContent in interface ContentReader

Throws:

ContentIOException

getContentString

public final String getContentString(int length)
                              throws ContentIOException

Specified by:

getContentString in interface ContentReader

Throws:

ContentIOException

getContentString

public final String getContentString()
                              throws ContentIOException

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

All the content is streamed into memory. So, like the interface said, be careful with this method.

Specified by:

getContentString in interface ContentReader

Throws:

ContentIOException

See Also:

ContentAccessor.getEncoding()

compareContentReaders

public static boolean compareContentReaders(ContentReader left,
                                            ContentReader right)
                                     throws ContentIOException

Does a comparison of the binaries associated with two readers. Several shortcuts are assumed to be valid:
- if the readers are the same instance, then the binaries are the same
- if the size field is different, then the binaries are different
Otherwise the binaries are compared.

Returns:

Returns true if the underlying binaries are the same

Throws:

ContentIOException