```
@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 Summary

Fields
Modifier and Type	Field	Description
`static ContentContext`	`NEW_CONTENT_CONTEXT`	An empty content context used to retrieve completely new content.
`static String`	`PROTOCOL_DELIMITER`	The delimiter that must be found in all URLS, i.e ://

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`boolean`	`delete(String contentUrl)`	Deletes the content at the given URL.
`boolean`	`exists(String contentUrl)`	Check for the existence of content in the store.
`default DirectAccessUrl`	`getDirectAccessUrl(String contentUrl, Date expiresAt)`	Gets a presigned URL to directly access a binary content.
`ContentReader`	`getReader(String contentUrl)`	Get the accessor with which to read from the content at the given URL.
`String`	`getRootLocation()`	Get the location where the store is rooted.
`long`	`getSpaceFree()`	Calculates the remaning free space in the underlying store.
`long`	`getSpaceTotal()`	Calculates the total storage space of the underlying store.
`ContentWriter`	`getWriter(ContentContext context)`	Get an accessor with which to write content to a location within the store.
`boolean`	`isContentUrlSupported(String contentUrl)`	Check if the content URL format is supported by the store.
`default boolean`	`isDirectAccessSupported()`	Checks if the store supports the retrieving of direct access URLs.
`boolean`	`isWriteSupported()`	Check if the store supports write requests.

- Field Detail
  - NEW_CONTENT_CONTEXT
```
static final ContentContext NEW_CONTENT_CONTEXT
```
    An empty content context used to retrieve completely new content.
    
    See Also:
    
    getWriter(ContentContext)
  - PROTOCOL_DELIMITER
```
static final String PROTOCOL_DELIMITER
```
    The delimiter that must be found in all URLS, i.e ://
    
    See Also:
    
    Constant Field Values
- 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
  - getDirectAccessUrl
```
default DirectAccessUrl getDirectAccessUrl(String contentUrl,
                                           Date expiresAt)
```
    Gets a presigned URL to directly access a binary 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
    
    expiresAt - An optional expiry date, so the direct access url would become invalid when the expiry date is reached
    
    Returns:
    
    A direct access URL object for a binary content
    
    Throws:
    
    UnsupportedOperationException - if the store is unable to provide the information
  - isDirectAccessSupported
```
default boolean isDirectAccessSupported()
```
    Checks if the store supports the retrieving of direct access URLs.
    
    Returns:
    
    true if direct access URLs retrieving is supported, false otherwise

Interface ContentStore

Field Summary

Method Summary

Field Detail

NEW_CONTENT_CONTEXT

PROTOCOL_DELIMITER

Method Detail

isContentUrlSupported

isWriteSupported

getSpaceFree

getSpaceTotal

getRootLocation

exists

getReader

getWriter

delete

getDirectAccessUrl

isDirectAccessSupported