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

    • Method Detail

      • 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:
        ContentReader.exists()

      • 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:
        exists(String), ContentReader.exists(), org.alfresco.repo.content.EmptyContentReader

      • 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:
        ContentAccessor.addListener(ContentStreamListener), ContentAccessor.getContentUrl()

      • 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

      • getObjectStorageProperties

        @Experimental
default Map<String,​String> getObjectStorageProperties​(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.