/*
* 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.sparql.resultset;
import java.io.BufferedWriter ;
import java.io.IOException ;
import java.io.OutputStream ;
import java.io.Writer ;
import java.util.ArrayList ;
import java.util.List ;
import org.openjena.atlas.lib.StrUtils ;
import org.openjena.riot.out.NodeFormatterTTL;
import com.hp.hpl.jena.graph.Node ;
import com.hp.hpl.jena.query.ResultSet ;
import com.hp.hpl.jena.sparql.ARQException ;
import com.hp.hpl.jena.sparql.core.Var ;
import com.hp.hpl.jena.sparql.engine.binding.Binding ;
import com.hp.hpl.jena.util.FileUtils ;
/**
* Tab Separated Values.
*
* First row is variable names (with ?).
* Subsequent rows are RDF terms, written Turtle style.
*/
public class TSVOutput extends OutputBase
{
// Tab Separated Values
// http://www.iana.org/assignments/media-types/text/tab-separated-values
static String NL = "\n" ;
static String SEP = "\t" ;
@Override
public void format(OutputStream out, ResultSet resultSet)
{
try {
//Use a Turtle formatter to format terms
NodeFormatterTTL formatter = new NodeFormatterTTL(null, null);
Writer w = FileUtils.asUTF8(out) ;
w = new BufferedWriter(w) ;
String sep = null ;
List<String> varNames = resultSet.getResultVars() ;
List<Var> vars = new ArrayList<Var>(varNames.size()) ;
// writes the variables on the first line
for( String v : varNames )
{
if ( sep != null )
w.write(sep) ;
else
sep = SEP ;
Var var = Var.alloc(v) ;
w.write(var.toString()) ;
vars.add(var) ;
}
w.write(NL) ;
// writes one binding by line
for ( ; resultSet.hasNext() ; )
{
sep = null ;
Binding b = resultSet.nextBinding() ;
for( Var v : vars )
{
if ( sep != null )
w.write(sep) ;
sep = SEP ;
Node n = b.get(v) ;
if ( n != null )
{
// This will not include a raw tab.
formatter.format(w, n);
}
}
w.write(NL) ;
}
w.flush() ;
} catch (IOException ex)
{
throw new ARQException(ex) ;
}
}
static final byte[] yesBytes = StrUtils.asUTF8bytes("yes") ;
static final byte[] noBytes = StrUtils.asUTF8bytes("no") ;
static final byte[] NLBytes = StrUtils.asUTF8bytes(NL) ;
@Override
public void format(OutputStream out, boolean booleanResult)
{
try
{
if (booleanResult)
out.write(yesBytes) ;
else
out.write(noBytes) ;
out.write(NLBytes) ;
} catch (IOException ex)
{
throw new ARQException(ex) ;
}
}
}