com.hp.hpl.jena.graph
Interface GraphMaker

public interface GraphMaker

A factory for providing instances of graphs with appropriate storage models. It is not part of the contract for this factory that each instance is unique; some applications may legitimately want to write triples into a single graph (such as a database).

Updated by kers; added methods that create or locate named graphs.

Version:

CVS $Id: GraphMaker.java,v 1.1 2003/05/08 15:19:31 chris-dollin Exp $

Author:

Ian Dickinson, HP Labs (email)

Method Summary

void	close() Close the factory - no more requests need be honoured, and any clean-up can be done.
Graph	createGraph(java.lang.String name) Create a graph that does not already exist - equivalent to createGraph( name, false ).
Graph	createGraph(java.lang.String name, boolean strict) Create a new graph associated with the given name.
Graph	getGraph() Answer an instance of a graph
boolean	hasGraph(java.lang.String name) return true iff the factory has a graph with the given name
Graph	openGraph(java.lang.String name) Equivalent to openGraph( name, false )
Graph	openGraph(java.lang.String name, boolean strict) Find an existing graph that this factory knows about under the given name.
void	removeGraph(java.lang.String name) Remove the association between the name and the graph. create will now be able to create a graph with that name, and open will no longer be able to find it.

Method Detail

getGraph

public Graph getGraph()

Answer an instance of a graph

Returns:

A new or existing graph.

createGraph

public Graph createGraph(java.lang.String name,
                         boolean strict)

Create a new graph associated with the given name. If there is no such association, create one and return it. If one exists but strict is false, return the associated graph. Otherwise throw an AlreadyExistsException.

Parameters:

name - the name to give to the new graph

strict - true to cause existing bindings to throw an exception

Throws:

AlreadyExistsException - if that name is already bound.

createGraph

public Graph createGraph(java.lang.String name)

Create a graph that does not already exist - equivalent to
createGraph( name, false ).

openGraph

public Graph openGraph(java.lang.String name,
                       boolean strict)

Find an existing graph that this factory knows about under the given name. If such a graph exists, return it. Otherwise, if strict is false, create a new graph, associate it with the name, and return it. Otherwise throw a DoesNotExistException.

Parameters:

name - the name of the graph to find and return

strict - false to create a new one if one doesn't already exist

Throws:

DoesNotExistException - if there's no such named graph

openGraph

public Graph openGraph(java.lang.String name)

Equivalent to openGraph( name, false )

removeGraph

public void removeGraph(java.lang.String name)

Remove the association between the name and the graph. create will now be able to create a graph with that name, and open will no longer be able to find it. Throws an exception if there's no such graph. The graph itself is not touched.

Parameters:

name - the name to disassociate

Throws:

DoesNotExistException - if the name is unbound

hasGraph

public boolean hasGraph(java.lang.String name)

return true iff the factory has a graph with the given name

Parameters:

name - the name of the graph to look for

Returns:

true iff there's a graph with that name

close

public void close()

Close the factory - no more requests need be honoured, and any clean-up can be done.