org.xmldb.api.base
Interface Collection

All Superinterfaces:

Configurable

All Known Implementing Classes:

CollectionImpl, SimpleCollection

public interface Collection

extends Configurable

A Collection represents a collection of Resources stored within an XML database. An XML database MAY expose collections as a hierarchical set of parent and child collections.

A Collection provides access to the Resources stored by the Collection and to Service instances that can operate against the Collection and the Resources stored within it. The Service mechanism provides the ability to extend the functionality of a Collection in ways that allows optional functionality to be enabled for the Collection.

Method Summary

void	close() Releases all resources consumed by the Collection.
java.lang.String	createId() Creates a new unique ID within the context of the Collection
Resource	createResource(java.lang.String id, java.lang.String type) Creates a new empty Resource with the provided id.
Collection	getChildCollection(java.lang.String name) Returns a Collection instance for the requested child collection if it exists.
int	getChildCollectionCount() Returns the number of child collections under this Collection or 0 if no child collections exist.
java.lang.String	getName() Returns the name associated with the Collection instance.
Collection	getParentCollection() Returns the parent collection for this collection or null if no parent collection exists.
Resource	getResource(java.lang.String id) Retrieves a Resource from the database.
int	getResourceCount() Returns the number of resources currently stored in this collection or 0 if the collection is empty.
Service	getService(java.lang.String name, java.lang.String version) Returns a Service instance for the requested service name and version.
Service[]	getServices() Provides a list of all services known to the collection.
boolean	isOpen() Returns true if the Collection is open false otherwise.
java.lang.String[]	listChildCollections() Returns a list of collection names naming all child collections of the current collection.
java.lang.String[]	listResources() Returns a list of the ids for all resources stored in the collection.
void	removeResource(Resource res) Removes the Resource from the database.
void	storeResource(Resource res) Stores the provided resource into the database.

Methods inherited from interface org.xmldb.api.base.Configurable

getProperty, setProperty

Method Detail

getName

public java.lang.String getName()
                         throws XMLDBException

Returns the name associated with the Collection instance.

Returns:

the name of the object.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.

getServices

public Service[] getServices()
                      throws XMLDBException

Provides a list of all services known to the collection. If no services are known an empty list is returned.

Returns:

An array of registered Service implementations.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

getService

public Service getService(java.lang.String name,
                          java.lang.String version)
                   throws XMLDBException

Returns a Service instance for the requested service name and version. If no Service exists for those parameters a null value is returned.

Parameters:

name - Description of Parameter

version - Description of Parameter

Returns:

the Service instance or null if no Service could be found.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

getParentCollection

public Collection getParentCollection()
                               throws XMLDBException

Returns the parent collection for this collection or null if no parent collection exists.

Returns:

the parent Collection instance.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

getChildCollectionCount

public int getChildCollectionCount()
                            throws XMLDBException

Returns the number of child collections under this Collection or 0 if no child collections exist.

Returns:

the number of child collections.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

listChildCollections

public java.lang.String[] listChildCollections()
                                        throws XMLDBException

Returns a list of collection names naming all child collections of the current collection. If no child collections exist an empty list is returned.

Returns:

an array containing collection names for all child collections.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

getChildCollection

public Collection getChildCollection(java.lang.String name)
                              throws XMLDBException

Returns a Collection instance for the requested child collection if it exists.

Parameters:

name - the name of the child collection to retrieve.

Returns:

the requested child collection or null if it couldn't be found.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

getResourceCount

public int getResourceCount()
                     throws XMLDBException

Returns the number of resources currently stored in this collection or 0 if the collection is empty.

Returns:

the number of resource in the collection.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

listResources

public java.lang.String[] listResources()
                                 throws XMLDBException

Returns a list of the ids for all resources stored in the collection.

Returns:

a string array containing the names for all Resources in the collection.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

createResource

public Resource createResource(java.lang.String id,
                               java.lang.String type)
                        throws XMLDBException

Creates a new empty Resource with the provided id. The type of Resource returned is determined by the type parameter. The XML:DB API currently defines "XMLResource" and "BinaryResource" as valid resource types. The id provided must be unique within the scope of the collection. If id is null or its value is empty then an id is generated by calling createId(). The Resource created is not stored to the database until storeResource() is called.

Parameters:

id - the unique id to associate with the created Resource.

type - the Resource type to create.

Returns:

an empty Resource instance.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.UNKNOWN_RESOURCE_TYPE if the type parameter is not a known Resource type. ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

removeResource

public void removeResource(Resource res)
                    throws XMLDBException

Removes the Resource from the database.

Parameters:

res - the resource to remove.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.INVALID_RESOURCE if the Resource is not valid.
ErrorCodes.NO_SUCH_RESOURCE if the Resource is not known to this Collection. ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

storeResource

public void storeResource(Resource res)
                   throws XMLDBException

Stores the provided resource into the database. If the resource does not already exist it will be created. If it does already exist it will be updated.

Parameters:

res - the resource to store in the database.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.INVALID_RESOURCE if the Resource is not valid. ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

getResource

public Resource getResource(java.lang.String id)
                     throws XMLDBException

Retrieves a Resource from the database. If the Resource could not be located a null value will be returned.

Parameters:

id - the unique id for the requested resource.

Returns:

The retrieved Resource instance.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

createId

public java.lang.String createId()
                          throws XMLDBException

Creates a new unique ID within the context of the Collection

Returns:

the created id as a string.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.
ErrorCodes.COLLECTION_CLOSED if the close method has been called on the Collection

isOpen

public boolean isOpen()
               throws XMLDBException

Returns true if the Collection is open false otherwise. Calling the close method on Collection will result in isOpen returning false. It is not safe to use Collection instances that have been closed.

Returns:

true if the Collection is open, false otherwise.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.

close

public void close()
           throws XMLDBException

Releases all resources consumed by the Collection. The close method must always be called when use of a Collection is complete. It is not safe to use a Collection after the close method has been called.

Throws:

XMLDBException - with expected error codes.
ErrorCodes.VENDOR_ERROR for any vendor specific errors that occur.