jena-arq/src-examples/arq/examples/riot/ExRIOT_5.java

/*
 * 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 arq.examples.riot ;

import java.io.InputStream ;
import java.io.Reader ;
import java.util.Iterator ;

import org.apache.jena.atlas.web.ContentType ;
import org.apache.jena.graph.Graph ;
import org.apache.jena.graph.Triple ;
import org.apache.jena.rdf.model.Model ;
import org.apache.jena.rdf.model.ModelFactory ;
import org.apache.jena.riot.* ;
import org.apache.jena.riot.adapters.RDFReaderRIOT ;
import org.apache.jena.riot.system.ErrorHandler ;
import org.apache.jena.riot.system.ErrorHandlerFactory ;
import org.apache.jena.riot.system.ParserProfile ;
import org.apache.jena.riot.system.StreamRDF ;
import org.apache.jena.sparql.sse.Item ;
import org.apache.jena.sparql.sse.SSE ;
import org.apache.jena.sparql.sse.builders.BuilderGraph ;
import org.apache.jena.sparql.util.Context ;

/** Example of using RIOT : register a new language */
public class ExRIOT_5
{
    public static void main(String... argv) {
        Lang lang = LangBuilder.create("SSE", "text/x-sse").addFileExtensions("rsse").build() ;
        // This just registers the name, not the parser.
        RDFLanguages.register(lang) ;

        // Register the parser factory.
        ReaderRIOTFactory factory = new SSEReaderFactory() ;
        RDFParserRegistry.registerLangTriples(lang, factory) ;

        // use it ...
        String filename = "data.rsse" ;
        // model.read(filename)
        Model model = RDFDataMgr.loadModel(filename) ;

        // print results.
        model.write(System.out, "TTL") ;

        // Optional extra:
        // If needed to set or override the syntax, register the name explicitly
        // ...
        System.out.println("## --") ;
        IO_Jena.registerForModelRead("SSE", RDFReaderSSE.class) ;
        // and use read( , "SSE")
        Model model2 = ModelFactory.createDefaultModel().read(filename, "SSE") ;
        model2.write(System.out, "TTL") ;
    }

    static class SSEReaderFactory implements ReaderRIOTFactory
    {
        @Override
        public ReaderRIOT create(Lang language) {
            return new SSEReader() ;
        }
    }

    static class SSEReader implements ReaderRIOT
    {
        private ErrorHandler errorHandler = ErrorHandlerFactory.getDefaultErrorHandler() ;
        
        // This is just an example - it reads a graph in
        // http://jena.apache.org/documentation/notes/sse.html
        // format. It is not a streaming parser; it creates some triples,
        // then send them to the output. This style might be useful for creating
        // triples from a converter process or program.

        @Override
        public void read(InputStream in, String baseURI, ContentType ct, StreamRDF output, Context context) {
            Item item = SSE.parse(in) ;
            read(item, baseURI, ct, output, context) ;

        }

        @Override
        public void read(Reader in, String baseURI, ContentType ct, StreamRDF output, Context context) {
            Item item = SSE.parse(in) ;
            read(item, baseURI, ct, output, context) ;
        }

        private void read(Item item, String baseURI, ContentType ct, StreamRDF output, Context context) {
            Graph graph = BuilderGraph.buildGraph(item) ;
            Iterator<Triple> iter = graph.find(null, null, null) ;
            for ( ; iter.hasNext() ; )
                output.triple(iter.next()) ;
        }

        @Override public ErrorHandler getErrorHandler()                     { return errorHandler ; }
        @Override public void setErrorHandler(ErrorHandler errorHandler)    { this.errorHandler = errorHandler ; }

        @Override
        public ParserProfile getParserProfile() {
            return null ;
        }

        @Override
        public void setParserProfile(ParserProfile profile) {}
    }

    // Model.read adapter - must be public.
    public static class RDFReaderSSE extends RDFReaderRIOT
    {
        public RDFReaderSSE() {
            super("SSE") ;
        }
    }

    /*
     * data.rsse : (graph (<s> <p1> 123) (<s> <p2> 456) )
     */
}