Package org.alfresco.repo.content

Interface ContentStore

@AlfrescoPublicApi public interface ContentStore
Provides low-level retrieval of content readers and writers.

Implementations of this interface should be soley responsible for providing persistence and retrieval of the content against a content URL.

Content URLs must consist of a prefix or protocol followed by an implementation-specific identifier. See TimeBasedFileContentUrlProvider and VolumeAwareContentUrlProvider implementations of FileContentUrlProvider For example, default content URL format for file stores is store://year/month/day/hour/minute/GUID.bin

  • store://: prefix identifying an Alfresco content stores regardless of the persistence mechanism.
  • year: year
  • month: 1-based month of the year
  • day: 1-based day of the month
  • hour: 0-based hour of the day
  • minute: 0-based minute of the hour
  • GUID: A unique identifier

Where the store cannot handle a particular content URL request, the UnsupportedContentUrlException must be generated. This will allow various implementations to provide fallback code to other stores where possible.

Where a store cannot serve a particular request because the functionality is just not available, the UnsupportedOperationException should be thrown. Once again, there may be fallback handling provided for these situations.

Since:
1.0
Author:
Derek Hulley

  • Field Details

  • Method Details

    • isContentUrlSupported

      boolean isContentUrlSupported(String contentUrl)
      Check if the content URL format is supported by the store.
      Parameters:
      contentUrl - the content URL to check
      Returns:
      Returns true if none of the other methods on the store will throw an UnsupportedContentUrlException when given this URL.
      Since:
      2.1

    • isWriteSupported

      boolean isWriteSupported()
      Check if the store supports write requests.
      Returns:
      Return true is the store supports write operations
      Since:
      2.1

    • getSpaceFree

      long getSpaceFree()
      Calculates the remaning free space in the underlying store.

      NOTE: For efficiency, some implementations may provide a guess.

      Implementations should focus on calculating a size value quickly, rather than accurately.

      Returns:
      Returns the total, possibly approximate, free space (in bytes) available to the store or -1 if no size data is available.
      Since:
      3.3.3

    • getSpaceTotal

      long getSpaceTotal()
      Calculates the total storage space of the underlying store.

      NOTE: For efficiency, some implementations may provide a guess.

      Implementations should focus on calculating a size value quickly, rather than accurately.

      Returns:
      Returns the total, possibly approximate, size (in bytes) of the underlying store or -1 if no size data is available.
      Since:
      3.3.3

    • getRootLocation

      String getRootLocation()
      Get the location where the store is rooted. The format of the returned value will depend on the specific implementation of the store.
      Returns:
      Returns the store's root location or . if no information is available

    • exists

      boolean exists(String contentUrl)
      Check for the existence of content in the store.

      The implementation of this may be more efficient than first getting a reader to check for existence, although that check should also be performed.

      Parameters:
      contentUrl - the path to the content
      Returns:
      Returns true if the content exists, otherwise false if the content doesn't exist or if the URL is not applicable to this store.
      Throws:
      org.alfresco.repo.content.UnsupportedContentUrlException - if the content URL supplied is not supported by the store
      ContentIOException - if an IO error occurs
      See Also:

    • getReader

      ContentReader getReader(String contentUrl)
      Get the accessor with which to read from the content at the given URL. The reader is stateful and can only be used once.
      Parameters:
      contentUrl - the path to where the content is located
      Returns:
      Returns a read-only content accessor for the given URL. There may be no content at the given URL, but the reader must still be returned.
      Throws:
      org.alfresco.repo.content.UnsupportedContentUrlException - if the content URL supplied is not supported by the store
      ContentIOException - if an IO error occurs
      See Also:

    • getWriter

      ContentWriter getWriter(ContentContext context)
      Get an accessor with which to write content to a location within the store. The writer is stateful and can only be used once. The location may be specified but must, in that case, be a valid and unused URL.

      The store will ensure that the new content URL will be valid for all subsequent read attempts.

      By supplying a reader to existing content, the store implementation may enable random access. The store implementation can enable this by copying the existing content into the new location before supplying a writer onto the new content.

      Parameters:
      context - the context of content.
      Returns:
      Returns a write-only content accessor
      Throws:
      UnsupportedOperationException - if the store is unable to provide the information
      UnsupportedContentUrlException - if the content URL supplied is not supported by the store
      ContentExistsException - if the content URL is already in use
      ContentIOException - if an IO error occurs
      See Also:

    • delete

      boolean delete(String contentUrl)
      Deletes the content at the given URL.

      A delete cannot be forced since it is much better to have the file remain longer than desired rather than deleted prematurely.

      Parameters:
      contentUrl - the URL of the content to delete
      Returns:
      Returns true if the content was deleted (either by this or another operation), otherwise false. If the content no longer exists, then true is returned.
      Throws:
      UnsupportedOperationException - if the store is unable to perform the action
      UnsupportedContentUrlException - if the content URL supplied is not supported by the store
      ContentIOException - if an error occurs if an IO error occurs

    • isContentDirectUrlEnabled

      default boolean isContentDirectUrlEnabled()
      Checks if the store supports the retrieving of direct access URLs.
      Returns:
      true if direct access URLs retrieving is supported, false otherwise

    • isContentDirectUrlEnabled

      default boolean isContentDirectUrlEnabled(String contentUrl)
      Checks if the store supports the retrieving of a direct access URL for the given node.
      Parameters:
      contentUrl - the URL of the content for which to request a direct access URL
      Returns:
      true if direct access URLs retrieving is supported for the node, false otherwise

    • requestContentDirectUrl

      @Deprecated default DirectAccessUrl requestContentDirectUrl(String contentUrl, boolean attachment, String fileName)
      Deprecated.
      Gets a presigned URL to directly access the content. It is up to the actual store implementation if it can fulfil this request with an expiry time or not.
      Parameters:
      contentUrl - A content store URL
      attachment - true if an attachment URL is requested, false for an embedded URL.
      fileName - File name of the content
      Returns:
      A direct access URL object for the content
      Throws:
      UnsupportedOperationException - if the store is unable to provide the information

    • requestContentDirectUrl

      default DirectAccessUrl requestContentDirectUrl(String contentUrl, boolean attachment, String fileName, String mimetype)
      Gets a presigned URL to directly access the content. It is up to the actual store implementation if it can fulfil this request with an expiry time or not.
      Parameters:
      contentUrl - A content store URL
      attachment - true if an attachment URL is requested, false for an embedded URL.
      fileName - File name of the content
      Returns:
      A direct access URL object for the content
      Throws:
      UnsupportedOperationException - if the store is unable to provide the information

    • requestContentDirectUrl

      @Deprecated default DirectAccessUrl requestContentDirectUrl(String contentUrl, boolean attachment, String fileName, Long validFor)
      Deprecated.
      Gets a presigned URL to directly access the content. It is up to the actual store implementation if it can fulfil this request with an expiry time or not.
      Parameters:
      contentUrl - A content store URL
      attachment - true if an attachment URL is requested, false for an embedded URL.
      fileName - File name of the content
      validFor - The time at which the direct access URL will expire.
      Returns:
      A direct access URL object for the content.
      Throws:
      UnsupportedOperationException - if the store is unable to provide the information

    • requestContentDirectUrl

      default DirectAccessUrl requestContentDirectUrl(String contentUrl, boolean attachment, String fileName, String mimetype, Long validFor)
      Gets a presigned URL to directly access the content. It is up to the actual store implementation if it can fulfil this request with an expiry time or not.
      Parameters:
      contentUrl - A content store URL
      attachment - true if an attachment URL is requested, false for an embedded URL.
      fileName - File name of the content
      mimetype - Mimetype of the content
      validFor - The time at which the direct access URL will expire.
      Returns:
      A direct access URL object for the content.
      Throws:
      UnsupportedOperationException - if the store is unable to provide the information

    • getStorageProperties

      default Map<String,String> getStorageProperties(String contentUrl)
      Gets a key-value (String-String) collection of storage headers/properties with their respective values. A particular Cloud Connector will fill in that data with Cloud Storage Provider generic data. Map may be also filled in with entries consisting of pre-defined Alfresco keys of ObjectStorageProps and their values. If empty Map is returned - no connector is present or connector is not supporting retrieval of the properties or cannot determine the properties.
      Parameters:
      contentUrl - the URL of the content for which the storage properties are to be retrieved.
      Returns:
      Returns a key-value (String-String) collection of storage headers/properties with their respective values.

    • requestSendContentToArchive

      default boolean requestSendContentToArchive(String contentUrl, Map<String,Serializable> archiveParams)
      Submit a request to send content to archive (offline) state. If no connector is present or connector is not supporting sending to archive, then UnsupportedOperationException will be returned. Specific connector will decide which storage class/tier will be set for content.
      Parameters:
      contentUrl - the URL of the content which is to be archived.
      archiveParams - a map of String-Serializable parameters defining Storage Provider specific request parameters (can be empty).
      Returns:
      true when request successful, false when unsuccessful.
      Throws:
      UnsupportedOperationException - when store is unable to handle request.

    • requestRestoreContentFromArchive

      default boolean requestRestoreContentFromArchive(String contentUrl, Map<String,Serializable> restoreParams)
      Submit a request to restore content from archive (offline) state. If no connector is present or connector is not supporting restoring fom archive, then UnsupportedOperationException will be returned. One of input parameters of this method is a map (String-Serializable) of Storage Provider specific input needed to perform proper restore. Keys of this map should be restricted to ContentRestoreParams enumeration. For AWS S3 map can indicating expiry days, Glacier restore tier. For Azure Blob map can indicate rehydrate priority.
      Parameters:
      contentUrl - the URL of the content which is to be archived.
      restoreParams - a map of String-Serializable parameters defining Storage Provider specific request parameters (can be empty).
      Returns:
      true when request successful, false when unsuccessful.
      Throws:
      UnsupportedOperationException - when store is unable to handle request.