org.xmldb.api.base

Interface Collection

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
voidclose()
Releases all resources consumed by the Collection.
StringcreateId()
Creates a new unique ID within the context of the Collection
ResourcecreateResource(String id, String type)
Creates a new empty Resource with the provided id.
CollectiongetChildCollection(String name)
Returns a Collection instance for the requested child collection if it exists.
intgetChildCollectionCount()
Returns the number of child collections under this Collection or 0 if no child collections exist.
StringgetName()
Returns the name associated with the Collection instance.
CollectiongetParentCollection()
Returns the parent collection for this collection or null if no parent collection exists.
ResourcegetResource(String id)
Retrieves a Resource from the database.
intgetResourceCount()
Returns the number of resources currently stored in this collection or 0 if the collection is empty.
ServicegetService(String name, 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.
booleanisOpen()
Returns true if the Collection is open false otherwise.
String[]listChildCollections()
Returns a list of collection names naming all child collections of the current collection.
String[]listResources()
Returns a list of the ids for all resources stored in the collection.
voidremoveResource(Resource res)
Removes the Resource from the database.
voidstoreResource(Resource res)
Stores the provided resource into the database.

Method Detail

close

public void close()
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.

createId

public String createId()
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

createResource

public Resource createResource(String id, String type)
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

getChildCollection

public Collection getChildCollection(String name)
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

getChildCollectionCount

public int getChildCollectionCount()
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

getName

public String getName()
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.

getParentCollection

public Collection getParentCollection()
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

getResource

public Resource getResource(String id)
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

getResourceCount

public int getResourceCount()
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

getService

public Service getService(String name, String version)
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

getServices

public Service[] getServices()
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

isOpen

public boolean isOpen()
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.

listChildCollections

public String[] listChildCollections()
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

listResources

public String[] listResources()
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

removeResource

public void removeResource(Resource res)
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)
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