/**
* 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.riot.writer;
import org.apache.jena.atlas.io.AWriter ;
import org.apache.jena.atlas.io.IO ;
import org.apache.jena.atlas.lib.Tuple ;
import org.apache.jena.riot.out.CharSpace ;
import org.apache.jena.riot.out.NodeFormatter ;
import org.apache.jena.riot.out.NodeFormatterNT ;
import org.apache.jena.riot.system.StreamRDF ;
import org.apache.jena.riot.system.StreamRDFLib ;
import com.hp.hpl.jena.graph.Node ;
import com.hp.hpl.jena.graph.Triple ;
import com.hp.hpl.jena.sparql.core.Quad ;
/** An output of triples / quads that is streaming.
* It writes N-triples/N-quads.
*/
public class WriterStreamRDFTuples implements StreamRDF
{
// This class is the overall structure - the NodeFormatter controls the
// appearance of the Nodes themselves.
private final AWriter out ;
private final NodeFormatter nodeFmt ;
/** Output tuples, using UTF8 output
* See {@linkplain StreamRDFLib#writer} for ways to create a AWriter object.
*/
public WriterStreamRDFTuples(AWriter w)
{
this(w, CharSpace.UTF8) ;
}
/** Output tuples, choosing ASCII or UTF8
* See {@linkplain StreamRDFLib#writer} for ways to create a AWriter object.
*/
public WriterStreamRDFTuples(AWriter w, CharSpace charSpace)
{
out = w ;
nodeFmt = new NodeFormatterNT(charSpace) ;
}
@Override
public void start()
{}
@Override
public void finish()
{ IO.flush(out) ; }
@Override
public void triple(Triple triple)
{
Node s = triple.getSubject() ;
Node p = triple.getPredicate() ;
Node o = triple.getObject() ;
format(s) ;
out.print(" ") ;
format(p) ;
out.print(" ") ;
format(o) ;
out.print(" .\n") ;
}
@Override
public void quad(Quad quad)
{
Node s = quad.getSubject() ;
Node p = quad.getPredicate() ;
Node o = quad.getObject() ;
Node g = quad.getGraph() ;
format(s) ;
out.print(" ") ;
format(p) ;
out.print(" ") ;
format(o) ;
if ( outputGraphSlot(g) )
{
out.print(" ") ;
format(g) ;
}
out.print(" .\n") ;
}
@Override
public void tuple(Tuple<Node> tuple)
{
boolean first = true ;
for ( Node n : tuple )
{
if ( ! first )
out.print(" ") ;
first = false ;
format(n) ;
}
out.print(" .\n") ;
}
private void format(Node n)
{
nodeFmt.format(out, n) ;
}
@Override
public void base(String base)
{}
@Override
public void prefix(String prefix, String iri)
{}
private static boolean outputGraphSlot(Node g)
{
return ( g != null && g != Quad.tripleInQuad && ! Quad.isDefaultGraph(g) ) ;
}
}