org.apache.wiki.providers

Interface WikiAttachmentProvider

All Superinterfaces:

WikiProvider

All Known Implementing Classes:

BasicAttachmentProvider, CachingAttachmentProvider

public interface WikiAttachmentProvider
extends WikiProvider

Defines an attachment provider - a class which is capable of saving binary data as attachments.

The difference between this class and WikiPageProvider is that there PageProviders handle Unicode text, whereas we handle binary data. While there are quite a lot of similarities in how we handle things, many providers can really use just one. In addition, since binary files can be really large, we rely on Input/OutputStreams.

Field Summary

Fields inherited from interface org.apache.wiki.WikiProvider

LATEST_VERSION

Method Summary

Modifier and Type	Method and Description
void	deleteAttachment(Attachment att) Removes an entire page from the repository.
void	deleteVersion(Attachment att) Removes a specific version from the repository.
Collection	findAttachments(QueryItem[] query) Finds attachments based on the query.
InputStream	getAttachmentData(Attachment att) Get attachment data.
Attachment	getAttachmentInfo(WikiPage page, String name, int version) Returns info about an attachment.
List	getVersionHistory(Attachment att) Returns version history.
List	listAllChanged(Date timestamp) Lists changed attachments since given date.
Collection	listAttachments(WikiPage page) Lists all attachments attached to a page.
void	moveAttachmentsForPage(String oldParent, String newParent) Move all the attachments for a given page so that they are attached to a new page.
void	putAttachmentData(Attachment att, InputStream data) Put new attachment data.

Methods inherited from interface org.apache.wiki.WikiProvider

getProviderInfo, initialize

Method Detail

putAttachmentData

void putAttachmentData(Attachment att,
                       InputStream data)
                throws ProviderException,
                       IOException

Put new attachment data.

Parameters:

att - Attachment object to add new data to

data - The stream from which the provider should read the data

Throws:

IOException - If writing fails

ProviderException - If there are other errors.

getAttachmentData

InputStream getAttachmentData(Attachment att)
                       throws ProviderException,
                              IOException

Get attachment data.

Parameters:

att - The attachment

Returns:

An InputStream which you contains the raw data of the object. It's your responsibility to close it.

Throws:

ProviderException - If the attachment cannot be found

IOException - If the attachment cannot be opened

listAttachments

Collection listAttachments(WikiPage page)
                    throws ProviderException

Lists all attachments attached to a page.

Parameters:

page - The page to list the attachments from.

Returns:

A collection of Attachment objects. May be empty, but never null.

Throws:

ProviderException - If something goes wrong when listing the attachments.

findAttachments

Collection findAttachments(QueryItem[] query)

Finds attachments based on the query.

Parameters:

query - An array of QueryItem objects to search for

Returns:

A Collection of Attachment objects. May be empty, but never null.

listAllChanged

List listAllChanged(Date timestamp)
             throws ProviderException

Lists changed attachments since given date. Can also be used to fetch a list of all pages.

This is different from WikiPageProvider, where you basically get a list of all pages, then sort them locally. However, since some providers can be more efficient in locating recently changed files (like any database) than our non-optimized Java code, it makes more sense to fetch the whole list this way.

To get all files, call this with Date(0L);

Parameters:

timestamp - List all files from this date onward.

Returns:

A List of Attachment objects, in most-recently-changed first order.

Throws:

ProviderException - If something goes wrong.

getAttachmentInfo

Attachment getAttachmentInfo(WikiPage page,
                             String name,
                             int version)
                      throws ProviderException

Returns info about an attachment.

Parameters:

page - The parent page

name - The name of the attachment

version - The version of the attachment (it's okay to use WikiPage.LATEST_VERSION to find the latest one)

Returns:

An attachment object

Throws:

ProviderException - If the attachment cannot be found or some other error occurs.

getVersionHistory

List getVersionHistory(Attachment att)

Returns version history. Each element should be an Attachment.

Parameters:

att - The attachment for which to find the version history for.

Returns:

A List of Attachment objects.

deleteVersion

void deleteVersion(Attachment att)
            throws ProviderException

Removes a specific version from the repository. The implementations should really do no more security checks, since that is the domain of the AttachmentManager. Just delete it as efficiently as you can.

Parameters:

att - Attachment to be removed. The version field is checked, and thus only that version is removed.

Throws:

ProviderException - If the attachment cannot be removed for some reason.

Since:

2.0.19.

deleteAttachment

void deleteAttachment(Attachment att)
               throws ProviderException

Removes an entire page from the repository. The implementations should really do no more security checks, since that is the domain of the AttachmentManager. Just delete it as efficiently as you can. You should also delete any auxiliary files and directories that belong to this attachment, IF they were created by this provider.

Parameters:

att - Attachment to delete.

Throws:

ProviderException - If the page could not be removed for some reason.

Since:

2.0.17.

moveAttachmentsForPage

void moveAttachmentsForPage(String oldParent,
                            String newParent)
                     throws ProviderException

Move all the attachments for a given page so that they are attached to a new page.

Parameters:

oldParent - Name of the page we are to move the attachments from.

newParent - Name of the page we are to move the attachments to.

Throws:

ProviderException - If the attachments could not be moved for some reason.