net.cnri.repository.layered

Class LayeredRepository

java.lang.Object

net.cnri.repository.AbstractRepository

net.cnri.repository.layered.LayeredRepository

All Implemented Interfaces:

DirectRepository, Repository

Direct Known Subclasses:

MigrationRepository

public class LayeredRepository
extends AbstractRepository
implements DirectRepository

The LayeredRepository is composed of two other repositories, a top and a bottom. When data is written to the LayeredRepository the writes first happen to the top and then are written to the bottom in a low priority background thread. This is useful if you have a slow persistent storage repository such as the EmbededRepository and want to have faster access to it. In such an example you can create a LayeredRepository with a MemoryRepository as the top and an EmbededRepository as the bottom.

Constructor Summary

Constructors

Constructor and Description
LayeredRepository(Repository top, Repository bottom)
LayeredRepository(Repository top, Repository bottom, boolean writesReachBottom)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the repository and release all resources.
static void	copyDataOrSetAttributeForMissing(DataElement source, DataElement target)
static void	copyForLayeredRepo(DigitalObject source, DigitalObject target)
void	createDataElement(java.lang.String handle, java.lang.String name) Creates a new data element with the given name in this digital object.
LayeredDigitalObject	createDigitalObject(java.lang.String handle) Creates a new digital object with the given identifier in this repository.
void	deleteAttribute(java.lang.String handle, java.lang.String elementName, java.lang.String name) Deletes a particular attribute.
void	deleteAttributes(java.lang.String handle, java.lang.String elementName, java.util.List<java.lang.String> names) Deletes multiple attributes.
void	deleteDataElement(java.lang.String handle, java.lang.String name) Deletes any data element of the given name.
void	deleteDigitalObject(java.lang.String handle) Deletes a digital object from the repository.
java.lang.String	getAttribute(java.lang.String handle, java.lang.String elementName, java.lang.String name) Returns the value for a particular attribute
java.util.Map<java.lang.String,java.lang.String>	getAttributes(java.lang.String handle, java.lang.String elementName) Returns a Map view of the attributes of the digital object or data element.
Repository	getBottom()
LayeredDigitalObject	getDigitalObject(java.lang.String handle) Returns the digital object with the given identifier from this repository.
java.io.File	getFile(java.lang.String handle, java.lang.String elementName) Returns a file for the data of the data element.
long	getSize(java.lang.String handle, java.lang.String elementName) Returns the number of bytes of data in this data element.
Repository	getTop()
void	lift(java.lang.String handle)
CloseableIterator<java.util.Map.Entry<java.lang.String,java.lang.String>>	listAttributes(java.lang.String handle, java.lang.String elementName) Returns a CloseableIterator view of the attributes of the digital object or data element.
CloseableIterator<java.lang.String>	listDataElementNames(java.lang.String handle) Provides a CloseableIterator view of the names of the data elements in this digital object.
CloseableIterator<java.lang.String>	listHandles() Provides a CloseableIterator view of the identifiers for digital objects accessible through this repository.
java.io.InputStream	read(java.lang.String handle, java.lang.String elementName) Provides access to the data as an InputStream.
CloseableIterator<DigitalObject>	search(Query query) Provides a CloseableIterator view of the digital objects accessible through this repository under search bounds defined in the Query object with default parameters.
CloseableIterator<java.lang.String>	searchHandles(Query query) Provides a CloseableIterator view of the digital objects handles accessible through this repository under search bounds defined in the Query object with default parameters.
void	setAttribute(java.lang.String handle, java.lang.String elementName, java.lang.String name, java.lang.String value) Sets a particular attribute.
void	setAttributes(java.lang.String handle, java.lang.String elementName, java.util.Map<java.lang.String,java.lang.String> attributes) Sets the value of multiple attributes.
boolean	verifyDataElement(java.lang.String handle, java.lang.String name) Verifies whether a data element with the given name exists within this digital object
boolean	verifyDigitalObject(java.lang.String handle) Verifies whether a digital object with the given identifier can be accessed via this repository.
long	write(java.lang.String handle, java.lang.String elementName, java.io.InputStream data, boolean append) Writes new data into the data element.

Methods inherited from class net.cnri.repository.AbstractRepository

getHandle, getOrCreateDigitalObject, listObjects, search, search, searchHandles, searchHandles, searchMapping

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface net.cnri.repository.Repository

getHandle, getOrCreateDigitalObject, listObjects, search, search, searchHandles, searchHandles, searchMapping

Constructor Detail

LayeredRepository

public LayeredRepository(Repository top,
                 Repository bottom)
                  throws RepositoryException

Throws:

RepositoryException

LayeredRepository

public LayeredRepository(Repository top,
                 Repository bottom,
                 boolean writesReachBottom)
                  throws RepositoryException

Throws:

RepositoryException

Method Detail

getTop

public Repository getTop()

getBottom

public Repository getBottom()

lift

public void lift(java.lang.String handle)
          throws RepositoryException

Throws:

RepositoryException

verifyDigitalObject

public boolean verifyDigitalObject(java.lang.String handle)
                            throws RepositoryException

Description copied from interface: Repository

Verifies whether a digital object with the given identifier can be accessed via this repository.

Specified by:

verifyDigitalObject in interface Repository

Overrides:

verifyDigitalObject in class AbstractRepository

Parameters:

handle - an identifier for a digital object

Returns:

whether a digital object with that identifier can be accessed via this repository

Throws:

RepositoryException

createDigitalObject

public LayeredDigitalObject createDigitalObject(java.lang.String handle)
                                         throws CreationException,
                                                RepositoryException

Description copied from interface: Repository

Creates a new digital object with the given identifier in this repository. Passing null requests that the repository assign a new unique identifier; this method will throw UnsupportedOperationException if the given repository does not support that functionality.

Specified by:

createDigitalObject in interface Repository

Parameters:

handle - the identifier for the new digital object, or null to request that the repository assign a new unique identifier.

Returns:

the newly-created digital object

Throws:

CreationException - if an object with the given identifier already exists within the repository

RepositoryException

getDigitalObject

public LayeredDigitalObject getDigitalObject(java.lang.String handle)
                                      throws RepositoryException

Description copied from interface: Repository

Returns the digital object with the given identifier from this repository.

Specified by:

getDigitalObject in interface Repository

Parameters:

handle - the identifier for the digital object

Returns:

the digital object, or null if no such object can be accessed through this repository

Throws:

RepositoryException

deleteDigitalObject

public void deleteDigitalObject(java.lang.String handle)
                         throws RepositoryException

Description copied from interface: Repository

Deletes a digital object from the repository.

Specified by:

deleteDigitalObject in interface Repository

Overrides:

deleteDigitalObject in class AbstractRepository

Parameters:

handle - the identifier for the digital object

Throws:

RepositoryException

listHandles

public CloseableIterator<java.lang.String> listHandles()

Description copied from interface: Repository

Provides a CloseableIterator view of the identifiers for digital objects accessible through this repository.

Specified by:

listHandles in interface Repository

Overrides:

listHandles in class AbstractRepository

search

public CloseableIterator<DigitalObject> search(Query query)
                                        throws RepositoryException

Description copied from interface: Repository

Provides a CloseableIterator view of the digital objects accessible through this repository under search bounds defined in the Query object with default parameters.

Specified by:

search in interface Repository

Overrides:

search in class AbstractRepository

Parameters:

query - the query to perform

Returns:

a CloseableIterator over the results. Some implementations may return QueryResults.

Throws:

RepositoryException

searchHandles

public CloseableIterator<java.lang.String> searchHandles(Query query)
                                                  throws RepositoryException

Description copied from interface: Repository

Provides a CloseableIterator view of the digital objects handles accessible through this repository under search bounds defined in the Query object with default parameters.

Specified by:

searchHandles in interface Repository

Overrides:

searchHandles in class AbstractRepository

Parameters:

query - the query to perform

Returns:

a CloseableIterator over the results. Some implementations may return QueryResults.

Throws:

RepositoryException

close

public void close()

Description copied from interface: Repository

Close the repository and release all resources.

Specified by:

close in interface Repository

copyForLayeredRepo

public static void copyForLayeredRepo(DigitalObject source,
                      DigitalObject target)
                               throws RepositoryException,
                                      java.io.IOException

Throws:

RepositoryException

java.io.IOException

copyDataOrSetAttributeForMissing

public static void copyDataOrSetAttributeForMissing(DataElement source,
                                    DataElement target)
                                             throws RepositoryException,
                                                    java.io.IOException

Throws:

RepositoryException

java.io.IOException

getAttributes

public java.util.Map<java.lang.String,java.lang.String> getAttributes(java.lang.String handle,
                                                             java.lang.String elementName)
                                                               throws RepositoryException

Description copied from interface: DirectRepository

Returns a Map view of the attributes of the digital object or data element.

Specified by:

getAttributes in interface DirectRepository

Returns:

a Map view of the attributes of the digital object or data element.

Throws:

RepositoryException

listAttributes

public CloseableIterator<java.util.Map.Entry<java.lang.String,java.lang.String>> listAttributes(java.lang.String handle,
                                                                                       java.lang.String elementName)
                                                                                         throws RepositoryException

Description copied from interface: DirectRepository

Returns a CloseableIterator view of the attributes of the digital object or data element.

Specified by:

listAttributes in interface DirectRepository

Returns:

a CloseableIterator view of the attributes of the digital object or data element.

Throws:

RepositoryException

getAttribute

public java.lang.String getAttribute(java.lang.String handle,
                            java.lang.String elementName,
                            java.lang.String name)
                              throws RepositoryException

Description copied from interface: DirectRepository

Returns the value for a particular attribute

Specified by:

getAttribute in interface DirectRepository

name - the attribute name

Returns:

the attribute value

Throws:

RepositoryException

setAttributes

public void setAttributes(java.lang.String handle,
                 java.lang.String elementName,
                 java.util.Map<java.lang.String,java.lang.String> attributes)
                   throws RepositoryException

Description copied from interface: DirectRepository

Sets the value of multiple attributes. Attributes mapped to null will be deleted.

Specified by:

setAttributes in interface DirectRepository

attributes - the attributes to set, mapped to their new values

Throws:

RepositoryException

setAttribute

public void setAttribute(java.lang.String handle,
                java.lang.String elementName,
                java.lang.String name,
                java.lang.String value)
                  throws RepositoryException

Description copied from interface: DirectRepository

Sets a particular attribute.

Specified by:

setAttribute in interface DirectRepository

name - the attribute name

value - the attribute value; if null, the attribute will be deleted.

Throws:

RepositoryException

deleteAttributes

public void deleteAttributes(java.lang.String handle,
                    java.lang.String elementName,
                    java.util.List<java.lang.String> names)
                      throws RepositoryException

Description copied from interface: DirectRepository

Deletes multiple attributes.

Specified by:

deleteAttributes in interface DirectRepository

names - the names of the attributes to delete

Throws:

RepositoryException

deleteAttribute

public void deleteAttribute(java.lang.String handle,
                   java.lang.String elementName,
                   java.lang.String name)
                     throws RepositoryException

Description copied from interface: DirectRepository

Deletes a particular attribute.

Specified by:

deleteAttribute in interface DirectRepository

name - the name of the attribute to delete

Throws:

RepositoryException

verifyDataElement

public boolean verifyDataElement(java.lang.String handle,
                        java.lang.String name)
                          throws RepositoryException

Description copied from interface: DirectRepository

Verifies whether a data element with the given name exists within this digital object

Specified by:

verifyDataElement in interface DirectRepository

name - an identifier for a data element

Returns:

whether that data element exists

Throws:

RepositoryException

createDataElement

public void createDataElement(java.lang.String handle,
                     java.lang.String name)
                       throws CreationException,
                              RepositoryException

Description copied from interface: DirectRepository

Creates a new data element with the given name in this digital object.

Specified by:

createDataElement in interface DirectRepository

name - the identifier for the new data element

Throws:

CreationException - if a data element with the given name already exists

RepositoryException

deleteDataElement

public void deleteDataElement(java.lang.String handle,
                     java.lang.String name)
                       throws RepositoryException

Description copied from interface: DirectRepository

Deletes any data element of the given name.

Specified by:

deleteDataElement in interface DirectRepository

name - the identifier for the data element

Throws:

RepositoryException

listDataElementNames

public CloseableIterator<java.lang.String> listDataElementNames(java.lang.String handle)
                                                         throws RepositoryException

Description copied from interface: DirectRepository

Provides a CloseableIterator view of the names of the data elements in this digital object.

Specified by:

listDataElementNames in interface DirectRepository

Throws:

RepositoryException

read

public java.io.InputStream read(java.lang.String handle,
                       java.lang.String elementName)
                         throws RepositoryException

Description copied from interface: DirectRepository

Provides access to the data as an InputStream.

Specified by:

read in interface DirectRepository

Returns:

an InputStream providing access to the data

Throws:

RepositoryException

write

public long write(java.lang.String handle,
         java.lang.String elementName,
         java.io.InputStream data,
         boolean append)
           throws java.io.IOException,
                  RepositoryException

Description copied from interface: DirectRepository

Writes new data into the data element.

Specified by:

write in interface DirectRepository

data - an InputStream streaming the new data

append - whether to append the new data to the existing data

Returns:

the number of bytes of data written

Throws:

java.io.IOException

RepositoryException

getSize

public long getSize(java.lang.String handle,
           java.lang.String elementName)
             throws RepositoryException

Description copied from interface: DirectRepository

Returns the number of bytes of data in this data element.

Specified by:

getSize in interface DirectRepository

Returns:

the number of bytes of data in this data element

Throws:

RepositoryException

getFile

public java.io.File getFile(java.lang.String handle,
                   java.lang.String elementName)
                     throws RepositoryException

Description copied from interface: DirectRepository

Returns a file for the data of the data element. Reading or writing the file corresponds to reading and writing the data element. If the repository does not support files for data elements, returns null.

Specified by:

getFile in interface DirectRepository

Returns:

A file for the data of the data element, or null if the repository does not support files for data elements.

Throws:

RepositoryException