/*
* 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.out;
import java.io.OutputStream;
import org.apache.jena.atlas.io.IndentedWriter ;
import org.apache.jena.atlas.lib.Closeable ;
import org.apache.jena.atlas.lib.Lib ;
import org.apache.jena.atlas.lib.Sink ;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.graph.Triple;
import com.hp.hpl.jena.sparql.core.Quad;
import com.hp.hpl.jena.sparql.serializer.SerializationContext;
import com.hp.hpl.jena.sparql.util.FmtUtils;
/**
* A class that print quads, SPARQL style (maybe good for Trig too?)
*/
public class SinkQuadBracedOutput implements Sink<Quad>, Closeable
{
protected static final int BLOCK_INDENT = 2 ;
protected final IndentedWriter out;
protected final SerializationContext sCxt;
protected boolean opened = false;
protected Node currentGraph;
public SinkQuadBracedOutput(OutputStream out)
{
this(out, null);
}
public SinkQuadBracedOutput(OutputStream out, SerializationContext sCxt)
{
this(new IndentedWriter(out), sCxt);
}
public SinkQuadBracedOutput(IndentedWriter out, SerializationContext sCxt)
{
if (out == null)
{
throw new IllegalArgumentException("out may not be null") ;
}
if (sCxt == null)
{
sCxt = new SerializationContext();
}
this.out = out;
this.sCxt = sCxt;
}
public void open()
{
out.println("{");
out.incIndent(BLOCK_INDENT);
opened = true;
}
private void checkOpen()
{
if (!opened)
{
throw new IllegalStateException("SinkQuadBracedOutput is not opened. Call open() first.");
}
}
@Override
public void send(Quad quad)
{
send(quad.getGraph(), quad.asTriple());
}
public void send(Node graphName, Triple triple)
{
checkOpen();
if (Quad.isDefaultGraph(graphName))
{
graphName = null;
}
if (!Lib.equal(currentGraph, graphName))
{
if (null != currentGraph)
{
out.decIndent(BLOCK_INDENT);
out.println("}");
}
if (null != graphName)
{
out.print("GRAPH ");
output(graphName);
out.println(" {");
out.incIndent(BLOCK_INDENT);
}
}
output(triple);
out.println(" .");
currentGraph = graphName;
}
private void output(Node node)
{
String n = FmtUtils.stringForNode(node, sCxt);
out.print(n);
}
private void output(Triple triple)
{
String s = FmtUtils.stringForNode(triple.getSubject(), sCxt) ;
String p = FmtUtils.stringForNode(triple.getPredicate(), sCxt) ;
String o = FmtUtils.stringForNode(triple.getObject(), sCxt) ;
out.print(s);
out.print(" ");
out.print(p);
out.print(" ");
out.print(o);
}
@Override
public void flush()
{
out.flush();
}
@Override
public void close()
{
if (opened)
{
if (null != currentGraph)
{
out.decIndent(BLOCK_INDENT);
out.println("}");
}
out.decIndent(BLOCK_INDENT);
out.print("}");
// Since we didn't create the OutputStream, we'll just flush it
flush();
opened = false;
}
}
}