/*
* 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) {
out.print(FmtUtils.stringForTriple(triple)) ;
}
@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 ;
}
}
}