com.exlibris.digitool.common.storage

Interface StoragePlugin

All Known Subinterfaces:

StorageHandler

All Known Implementing Classes:

AbstractStorageHandler

public interface StoragePlugin

A plugin to handle storage access. This plugin interface supports java implementation only.
Inherit from AbstractStorageHandler and don't implement this interface directly.

In order to enable a storage access check during the system check's StorageAccessChecker, override the method: public boolean isAvailable()

Author:

PeterK

Method Summary

Methods

Modifier and Type	Method and Description
boolean	checkFixity(java.util.List<Fixity> fixities, java.lang.String storedEntityIdentifier) Calculates the fixities and checks that the file fixity hasn't changed. The check is made against the union of the fixities list and the fixities the plugin implementation supports, for example: if the list contains SHA1 and MD5 but the plugin supports only MD5, than the SHA1 entry would be ignored.
boolean	deleteEntity(java.lang.String storedEntityIdentifier) Deletes the entity from the storage
java.lang.String	getFullFilePath(java.lang.String storedEntityIdentifier) This method should return a full path that would be stored in the METS.
java.lang.String	getLocalFilePath(java.lang.String storedEntityIdentifier) Returns a local NFS path which can be used to access the file directly.
java.io.InputStream	retrieveEntity(java.lang.String storedEntityIdentifier) Used to read the entity data.
byte[]	retrieveEntityByRange(java.lang.String storedEntityIdentifier, long start, long end) This method returns an array of bytes containing the content of the StoredEntityIdentifier file within the defined Byte range.
java.lang.String	storeEntity(java.io.InputStream is, StoredEntityMetaData storedEntityMetadata) Stores the entity sent to the function.

Method Detail

storeEntity

java.lang.String storeEntity(java.io.InputStream is,
                           StoredEntityMetaData storedEntityMetadata)
                             throws java.lang.Exception

Stores the entity sent to the function.

Parameters:

is - an input stream to read from, if necessary (the input steam isn't used when storedEntityMetadata.getCurrentFilePath isn't null and can be used instead).

storedEntityMetadata - some metadata about the entity, like its type (IE, FILE, MD, SIP) & location. See StoredEntityMetaData.

Returns:

A stored entity identifier - which can be used in later calls for retrieving,deleting, etc' the stored entity.

Throws:

java.lang.Exception - on any error when saving the entity.

retrieveEntity

java.io.InputStream retrieveEntity(java.lang.String storedEntityIdentifier)
                                   throws java.io.IOException

Used to read the entity data.

Parameters:

storedEntityIdentifier - the identifier returned by storeEntity.

Returns:

An input stream which can be used to read the entity data.

Throws:

java.io.IOException - when failing to get an input stream.

deleteEntity

boolean deleteEntity(java.lang.String storedEntityIdentifier)
                     throws java.io.IOException

Deletes the entity from the storage

Parameters:

storedEntityIdentifier - the identifier returned by storeEntity.

Returns:

true if the file was deleted, false otherwise.

Throws:

java.io.IOException - when an unexpected error occurs.

checkFixity

boolean checkFixity(java.util.List<Fixity> fixities,
                  java.lang.String storedEntityIdentifier)
                    throws java.lang.Exception

Calculates the fixities and checks that the file fixity hasn't changed.
The check is made against the union of the fixities list and the fixities the plugin implementation supports, for example: if the list contains SHA1 and MD5 but the plugin supports only MD5, than the SHA1 entry would be ignored.
If there are no shared fixities - true should be returned. The plugin may delegate the list of fixities it can't calculate to AbstractStorageHandler.getChecksumUsingPlugin(String, String, String).

Parameters:

fixities - a list of the known file fixities to be compared with. When the method is completed each element of the list should have its result set: null if this fixity was ignored, True if the validation succeeded, False if the fixity value that was calculated doesn't match the value sent. In the case of a failure, the value in a fixity element should be set to the new value.

storedEntityIdentifier - the identifier returned by storeEntity.

Returns:

true if all the fixities are correct, false otherwise.

Throws:

java.lang.Exception - on any unexpected error.

getFullFilePath

java.lang.String getFullFilePath(java.lang.String storedEntityIdentifier)

This method should return a full path that would be stored in the METS.

Parameters:

storedEntityIdentifier - the identifier returned by storeEntity.

Returns:

A path to be stored in the METS.

getLocalFilePath

java.lang.String getLocalFilePath(java.lang.String storedEntityIdentifier)

Returns a local NFS path which can be used to access the file directly. This may cause the file to be copied from the storage, if the file isn't present locally.
The recommended location for the file is AbstractStorageHandler.getTempStorageDirectory().

Use this method when you need direct access to the file (for example when performing a virus check).

Parameters:

storedEntityIdentifier - the identifier returned by storeEntity.

Returns:

A local NFS path which can be used to access the file directly.

retrieveEntityByRange

byte[] retrieveEntityByRange(java.lang.String storedEntityIdentifier,
                           long start,
                           long end)
                             throws java.lang.Exception

This method returns an array of bytes containing the content of the StoredEntityIdentifier file within the defined Byte range.

Parameters:

storedEntityIdentifier - the identifier returned by storeEntity.

start - the starting Byte location of the desired range.

end - the ending Byte location of the desired range.

Returns:

an array of bytes containing the content of the StoredEntityIdentifier file within the defined Byte range.

Throws:

java.lang.Exception