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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.
*/
package org.apache.jena.riot.lang;
import org.apache.jena.graph.Node ;
import org.apache.jena.riot.Lang ;
import org.apache.jena.riot.RDFLanguages ;
import org.apache.jena.riot.system.ParserProfile ;
import org.apache.jena.riot.system.StreamRDF ;
import org.apache.jena.riot.tokens.Token ;
import org.apache.jena.riot.tokens.TokenType ;
import org.apache.jena.riot.tokens.Tokenizer ;
import org.apache.jena.sparql.core.Quad ;
/**
* N-Quads.
*
* @see http://www.w3.org/TR/n-quads/
*/
public class LangNQuads extends LangNTuple
{
// Null for no graph.
private Node currentGraph = null ;
public LangNQuads(Tokenizer tokens, ParserProfile profile, StreamRDF dest)
{
super(tokens, profile, dest) ;
}
@Override
public Lang getLang() { return RDFLanguages.NQUADS ; }
/** Method to parse the whole stream of triples, sending each to the sink */
@Override
protected final void runParser()
{
while(hasNext())
{
Quad x = parseOne() ;
if ( x != null )
dest.quad(x) ;
}
}
@Override
protected final Quad parseOne()
{
Token sToken = nextToken() ;
if ( sToken.getType() == TokenType.EOF )
exception(sToken, "Premature end of file: %s", sToken) ;
Token pToken = nextToken() ;
if ( pToken.getType() == TokenType.EOF )
exception(pToken, "Premature end of file: %s", pToken) ;
Token oToken = nextToken() ;
if ( oToken.getType() == TokenType.EOF )
exception(oToken, "Premature end of file: %s", oToken) ;
Token xToken = nextToken() ; // Maybe DOT
if ( xToken.getType() == TokenType.EOF )
exception(xToken, "Premature end of file: Quad not terminated by DOT: %s", xToken) ;
// Process graph node first, before S,P,O
// to set bnode label scope (if not global)
Node c = null ;
if ( xToken.getType() != TokenType.DOT )
{
// Allow bNodes for graph names.
checkIRIOrBNode(xToken) ;
// Allow only IRIs
//checkIRI(xToken) ;
c = tokenAsNode(xToken) ;
xToken = nextToken() ;
currentGraph = c ;
}
else
{
c = Quad.defaultGraphNodeGenerated ;
currentGraph = null ;
}
// createQuad may also check but these checks are cheap and do form syntax errors.
checkIRIOrBNode(sToken) ;
checkIRI(pToken) ;
checkRDFTerm(oToken) ;
// xToken already checked.
Node s = tokenAsNode(sToken) ;
Node p = tokenAsNode(pToken) ;
Node o = tokenAsNode(oToken) ;
// Check end of tuple.
if ( xToken.getType() != TokenType.DOT )
exception(xToken, "Quad not terminated by DOT: %s", xToken) ;
return profile.createQuad(c, s, p, o, sToken.getLine(), sToken.getColumn()) ;
}
@Override
protected final Node tokenAsNode(Token token) {
return profile.create(currentGraph, token);
}
}