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ARQ is a SPARQL 1.1 query engine for Apache Jena
/*
* 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.
*/
/** Code to calculate the transitive-bNode closures */
package org.apache.jena.sparql.util;
import java.util.ArrayList ;
import java.util.Collection ;
import java.util.List ;
import org.apache.jena.rdf.model.* ;
import org.apache.jena.sparql.graph.GraphFactory ;
public class Closure
{
/** Calculate the bNode closure from a statement .
* The Statement itself does not automatically get included.
* @param stmt
* @return A model containing statements
*/
public static Model closure(Statement stmt)
{
return closure(stmt, new ClosureBNode()) ;
}
/** Calculate the bNode closure from a statement .
* The Statement itself does not automatically get included.
* @param statement Starting point for the closure.
* @param test The test object to be applied
* @return A model containing statements
* @see ClosureTest
*/
public static Model closure(Statement statement, ClosureTest test)
{
return closure(statement, test, GraphFactory.makeJenaDefaultModel()) ;
}
/** Calculate the bNode closure from a statement .
* The Statement itself does not automatically get included.
* @param statement Starting point for the closure.
* @param model Add the statements to this model
* @return A model containing statements
* @see ClosureTest
*/
public static Model closure(Statement statement, Model model)
{
return closure(statement, new ClosureBNode(), model) ;
}
/** Calculate the bNode closure from a statement .
* The Statement itself does not automatically get included.
* @param statement Starting point for the closure.
* @param test The test object to be applied
* @param model Add the statements to this model
* @return A model containing statements
* @see ClosureTest
*/
public static Model closure(Statement statement, ClosureTest test, Model model)
{
//Set visited = new HashSet() ;
List visited = new ArrayList<>() ;
closure(statement, model, visited, test) ;
return model ;
}
/** Calculate the bNode closure from a resource.
* The Statement itself does not automatically get included.
* @param resource Starting point for the closure.
* @param testThisNode Indicate whether to apply the closure test to the Resource argument.
* @return A model containing statements
*/
public static Model closure(Resource resource, boolean testThisNode)
{
return closure(resource, new ClosureBNode(), testThisNode) ;
}
/** Calculate the bNode closure from a resource .
* The Statement itself does not automatically get included.
* @param resource
* @param test The test object to be applied
* @param testThisNode Indicate whether to apply the closure test to the Resource argument.
* @return A model containing statements
*/
public static Model closure(Resource resource, ClosureTest test, boolean testThisNode)
{
return closure(resource, test, testThisNode, GraphFactory.makeJenaDefaultModel()) ;
}
/** Calculate the bNode closure from a resource .
* The Statement itself does not automatically get included.
* @param resource
* @param testThisNode Indicate whether to apply the closure test to the Resource argument.
* @param results Add the statements to this model
* @return A model containing statements
*/
public static Model closure(Resource resource, boolean testThisNode, Model results)
{
return closure(resource, new ClosureBNode(), testThisNode, results) ;
}
/** Calculate the bNode closure from a resource .
* The Statement itself does not automatically get included.
* @param resource
* @param test The test object to be applied
* @param testThisNode Indicate whether to apply the closure test to the Resource argument.
* @param results Add the statements to this model
* @return A model containing statements
*/
public static Model closure(Resource resource, ClosureTest test,
boolean testThisNode, Model results)
{
//Set s = new HashSet() ;
//Set visited = new HashSet() ;
List visited = new ArrayList<>() ;
if ( ! testThisNode )
closureNoTest(resource, results, visited, test) ;
else
closure(resource, results, visited, test) ;
return results ;
}
// --------------------------------------------------------------------------------
private static void closure(Statement stmt,
Model closureBlob, Collection visited,
ClosureTest test)
{
if ( test.includeStmt(stmt) )
closureBlob.add(stmt) ;
closure(stmt.getSubject(), closureBlob, visited, test) ;
closure(stmt.getObject(), closureBlob, visited, test) ;
}
private static void closure(RDFNode n,
Model closureBlob, Collection visited,
ClosureTest test)
{
if ( ! ( n instanceof Resource ) )
return ;
Resource r = (Resource)n ;
if ( visited.contains(r) )
return ;
if ( ! test.traverse(r) )
return ;
closureNoTest(r, closureBlob, visited, test) ;
}
private static void closureNoTest(Resource r,
Model closureBlob, Collection visited,
ClosureTest test)
{
visited.add(r) ;
StmtIterator sIter = r.listProperties() ;
for ( ; sIter.hasNext() ; )
{
Statement stmt = sIter.nextStatement() ;
closure(stmt, closureBlob, visited, test) ;
}
}
private static String dbg_string(Collection s)
{
String tmp = "" ;
for ( Object value : s )
{
tmp = tmp + " " + value.toString();
}
return tmp ;
}
// Defines the bNode closure
public static class ClosureBNode implements ClosureTest
{
@Override
public boolean traverse(Resource r)
{
return r.isAnon() ;
}
@Override
public boolean includeStmt(Statement s)
{
return true ;
}
}
// Defines the reachable (on forward arcs) subgraph.
public static class ClosureReachable implements ClosureTest
{
@Override
public boolean traverse(Resource r)
{
return true ;
}
@Override
public boolean includeStmt(Statement s)
{
return true ;
}
}
}