/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.rdf.model;
/**
A ModelGetter object can retrieve a Model given a URL for it. If it doesn't
have such a Model, it returns null.
<p>
ModelGetters are very weakly constrained. They need not contain any
models at all; they may forget models they have just delivered; they may
deliver different models given the same URL. They <i>are</i> constrained to
deliver an "appropriate" model for the URL, however - whatever they return
should be strongly related to the RDF which might, at some time or another,
be retrieved from that URL.
*/
public interface ModelGetter
{
/**
Answer a Model whose content is that associated with the URL, if possible,
and otherwise answer null.
*/
public Model getModel( String URL );
/**
Answer a model appropriate for <code>URL</code>, If none is to hand,
and it's possible to create one, create it and load it using <code>loadIfAbsent</code>.
Otherwise throw CannotCreateException. This method never returns null.
*/
public Model getModel( String URL, ModelReader loadIfAbsent );
}