/*
* 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 com.hp.hpl.jena.assembler;
import java.util.*;
import com.hp.hpl.jena.graph.Graph;
import com.hp.hpl.jena.graph.compose.MultiUnion;
import com.hp.hpl.jena.rdf.model.*;
import com.hp.hpl.jena.util.FileManager;
import com.hp.hpl.jena.vocabulary.*;
public class ImportManager
{
public ImportManager()
{}
/**
A shared instance of ImportManage, used as a default by several other
assembler methods.
*/
public final static ImportManager instance = new ImportManager();
/**
The cache of models already read by this manager.
*/
protected Map<String, Graph> cache = new HashMap<>();
/**
Clear this ImportManager's cache.
*/
public void clear()
{ cache.clear(); }
/**
Answer <code>model</code> if it has no imports, or a union model with
<code>model</code> as its base and its imported models as the other
components. The default file manager is used to load the models.
*/
public Model withImports( Model model )
{ return withImports( FileManager.get(), model ); }
/**
Answer <code>model</code> if it has no imports, or a union model with
<code>model</code> as its base and its imported models as the other
components. The file manager <code>fm</code> is used to load the
imported models.
*/
public Model withImports( FileManager fm, Model model )
{ return withImports( fm, model, new HashSet<String>() ); }
private Model withImports( FileManager fm, Model model, Set<String> loading )
{
StmtIterator oit = model.listStatements( null, OWL.imports, (RDFNode) null );
StmtIterator jit = model.listStatements( null, JA.imports, (RDFNode) null );
if (oit.hasNext() || jit.hasNext())
{
MultiUnion g = new MultiUnion( new Graph[] { model.getGraph() } );
addImportedGraphs( fm, loading, oit, g );
addImportedGraphs( fm, loading, jit, g );
return ModelFactory.createModelForGraph( g );
}
else
return model;
}
private void addImportedGraphs( FileManager fm, Set<String> loading, StmtIterator oit, MultiUnion g )
{
while (oit.hasNext())
{
String path = getObjectURI( oit.nextStatement() );
if (loading.add( path )) g.addGraph( graphFor( fm, loading, path ) );
}
}
private String getObjectURI( Statement s )
{
RDFNode ob = s.getObject();
if (ob.isLiteral()) return AssemblerHelp.getString( s );
if (ob.isAnon()) throw new BadObjectException( s );
return ((Resource) ob).getURI();
}
protected Graph graphFor( FileManager fm, Set<String> loading, String path )
{
Graph already = cache.get( path );
if (already == null)
{
Graph result = withImports( fm, fm.loadModel( path ), loading ).getGraph();
cache.put( path, result );
return result;
}
else
return already;
}
}