Package org.apache.wiki.providers

Class CachingAttachmentProvider

java.lang.Object
org.apache.wiki.providers.CachingAttachmentProvider
All Implemented Interfaces:
AttachmentProvider, WikiProvider
public class CachingAttachmentProvider
extends java.lang.Object
implements AttachmentProvider
Provides a caching attachment provider. This class rests on top of a real provider class and provides a cache to speed things up. Only the Attachment objects are cached; the actual attachment contents are fetched always from the provider.
Since:
2.1.64.

  • Field Details

  • Constructor Details

  • Method Details

    • initialize

      public void initialize​(Engine engine, java.util.Properties properties) throws NoRequiredPropertyException, java.io.IOException
      Initializes the page provider.
      Specified by:
      initialize in interface WikiProvider
      Parameters:
      engine - Engine to own this provider
      properties - A set of properties used to initialize this provider
      Throws:
      NoRequiredPropertyException - If the provider needs a property which is not found in the property set
      java.io.IOException - If there is an IO problem

    • putAttachmentData

      public void putAttachmentData​(Attachment att, java.io.InputStream data) throws ProviderException, java.io.IOException
      Put new attachment data.
      Specified by:
      putAttachmentData in interface AttachmentProvider
      Parameters:
      att - Attachment object to add new data to
      data - The stream from which the provider should read the data
      Throws:
      ProviderException - If there are other errors.
      java.io.IOException - If writing fails

    • getAttachmentData

      public java.io.InputStream getAttachmentData​(Attachment att) throws ProviderException, java.io.IOException
      Get attachment data.
      Specified by:
      getAttachmentData in interface AttachmentProvider
      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
      java.io.IOException - If the attachment cannot be opened

    • listAttachments

      public java.util.List<Attachment> listAttachments​(Page page) throws ProviderException
      Lists all attachments attached to a page.
      Specified by:
      listAttachments in interface AttachmentProvider
      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

      public java.util.Collection<Attachment> findAttachments​(QueryItem[] query)
      Finds attachments based on the query.
      Specified by:
      findAttachments in interface AttachmentProvider
      Parameters:
      query - An array of QueryItem objects to search for
      Returns:
      A Collection of Attachment objects. May be empty, but never null.

    • listAllChanged

      public java.util.List<Attachment> listAllChanged​(java.util.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);

      Specified by:
      listAllChanged in interface AttachmentProvider
      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

      public Attachment getAttachmentInfo​(Page page, java.lang.String name, int version) throws ProviderException
      Returns info about an attachment.
      Specified by:
      getAttachmentInfo in interface AttachmentProvider
      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

      public java.util.List<Attachment> getVersionHistory​(Attachment att)
      Returns version history. Each element should be an Attachment.
      Specified by:
      getVersionHistory in interface AttachmentProvider
      Parameters:
      att - The attachment for which to find the version history for.
      Returns:
      A List of Attachment objects.

    • deleteVersion

      public 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.
      Specified by:
      deleteVersion in interface AttachmentProvider
      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.

    • deleteAttachment

      public 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.
      Specified by:
      deleteAttachment in interface AttachmentProvider
      Parameters:
      att - Attachment to delete.
      Throws:
      ProviderException - If the page could not be removed for some reason.

    • getProviderInfo

      public java.lang.String getProviderInfo()
      Gets the provider class name, and cache statistics (misscount and,hitcount of the attachment cache).
      Specified by:
      getProviderInfo in interface WikiProvider
      Returns:
      A plain string with all the above mentioned values.

    • getRealProvider

      public AttachmentProvider getRealProvider()
      Returns the WikiAttachmentProvider that this caching provider delegates to.
      Returns:
      The real provider underneath this one.

    • moveAttachmentsForPage

      public void moveAttachmentsForPage​(java.lang.String oldParent, java.lang.String newParent) throws ProviderException
      Move all the attachments for a given page so that they are attached to a new page.
      Specified by:
      moveAttachmentsForPage in interface AttachmentProvider
      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.