Package org.dspace.ctask.replicate

Interface ObjectStore

All Known Implementing Classes:

DuraCloudObjectStore, LocalObjectStore, MountableObjectStore

public interface ObjectStore

An ObjectStore provides access to a managed store containing objects that possess a set of attributes. ObjectStores allow storage within named containers, here called groups.

Author:

richardrodgers

Method Summary

Modifier and Type	Method	Description
long	fetchObject(String group, String id, File file)	Fetches a copy of the object with passed ID, and places it in passed file.
void	init()	Initializes the storage service for use.
long	moveObject(String srcgroup, String destGroup, String id)	Moves the passed object from one storage group to another.
String	objectAttribute(String group, String id, String attrName)	Obtains attributes of the representation of the object with passed ID.
boolean	objectExists(String group, String id)	Returns whether an object with the passed id exists in the store.
long	removeObject(String group, String id)	Removes the passed object from the store.
long	transferObject(String group, File file)	Transfers a copy of this file to the object store

Method Detail

init

void init()
   throws IOException

Initializes the storage service for use.

Throws:

IOException - if I/O error

objectExists

boolean objectExists(String group,
                     String id)
              throws IOException

Returns whether an object with the passed id exists in the store.

Parameters:

group - Group

id - ID

Returns:

true if a representation of the object named by ID exists

Throws:

IOException - if I/O error

objectAttribute

String objectAttribute(String group,
                       String id,
                       String attrName)
                throws IOException

Obtains attributes of the representation of the object with passed ID.

Parameters:

group - Group

id - ID

attrName - - name of the attribute

Returns:

value of the attribute if it exists, else null

Throws:

IOException - if I/O error

fetchObject

long fetchObject(String group,
                 String id,
                 File file)
          throws IOException

Fetches a copy of the object with passed ID, and places it in passed file.

Parameters:

group - Group

id - ID

file - File

Returns:

number of bytes the replica used

Throws:

IOException - if I/O error

transferObject

long transferObject(String group,
                    File file)
             throws IOException

Transfers a copy of this file to the object store

Parameters:

group - Group

file - the file to transfer to store

Returns:

number of bytes transferred to store or 0 if transfer failed.

Throws:

IOException - if I/O error

removeObject

long removeObject(String group,
                  String id)
           throws IOException

Removes the passed object from the store.

Parameters:

group - Group

id - the id of the object to remove

Returns:

number of bytes the object was using, or 0 if object did not exist.

Throws:

IOException - if I/O error

moveObject

long moveObject(String srcgroup,
                String destGroup,
                String id)
         throws IOException

Moves the passed object from one storage group to another.

Parameters:

srcgroup - source group

destGroup - destination group

id - the id of the object to move between groups

Returns:

number of bytes moved or 0 if move failed.

Throws:

IOException - if I/O error