/**
* 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.resultset;
import static org.apache.jena.riot.resultset.ResultSetLang.SPARQLResultSetCSV ;
import static org.apache.jena.riot.resultset.ResultSetLang.SPARQLResultSetJSON ;
import static org.apache.jena.riot.resultset.ResultSetLang.SPARQLResultSetTSV ;
import static org.apache.jena.riot.resultset.ResultSetLang.SPARQLResultSetThrift ;
import static org.apache.jena.riot.resultset.ResultSetLang.SPARQLResultSetXML ;
import java.io.InputStream ;
import java.io.Reader ;
import java.util.HashMap ;
import java.util.Map ;
import java.util.Objects ;
import org.apache.jena.atlas.lib.NotImplemented ;
import org.apache.jena.query.ResultSet ;
import org.apache.jena.riot.Lang ;
import org.apache.jena.riot.RiotException ;
import org.apache.jena.riot.thrift.BinRDF ;
import org.apache.jena.sparql.resultset.CSVInput ;
import org.apache.jena.sparql.resultset.JSONInput ;
import org.apache.jena.sparql.resultset.TSVInput ;
import org.apache.jena.sparql.resultset.XMLInput ;
import org.apache.jena.sparql.util.Context ;
public class ResultSetReaderRegistry {
/** Lookup a {@link Lang} to get the registered {@link ResultSetReaderFactory} (or null) */
public static ResultSetReaderFactory getFactory(Lang lang) {
Objects.requireNonNull(lang) ;
return registry.get(lang) ;
}
/** Register a {@link ResultSetReaderFactory} for a {@link Lang} */
public static void register(Lang lang, ResultSetReaderFactory factory) {
Objects.requireNonNull(lang) ;
Objects.requireNonNull(factory) ;
registry.put(lang, factory) ;
}
private static Map<Lang, ResultSetReaderFactory> registry = new HashMap<>() ;
private static boolean initialized = false ;
public static void init() {
if ( initialized )
return ;
initialized = true ;
ResultSetReaderFactory factory = new ResultSetReaderFactoryStd() ;
register(SPARQLResultSetXML, factory) ;
register(SPARQLResultSetJSON, factory) ;
register(SPARQLResultSetCSV, factory) ;
register(SPARQLResultSetTSV, factory) ;
register(SPARQLResultSetThrift, factory) ;
}
static { ResultSetLang.init(); }
private static class ResultSetReaderFactoryStd implements ResultSetReaderFactory {
@Override
public ResultSetReader create(Lang lang) {
lang = Objects.requireNonNull(lang, "Language must not be null") ;
if ( lang.equals(SPARQLResultSetXML) ) return readerXML ;
if ( lang.equals(SPARQLResultSetJSON) ) return readerJSON ;
if ( lang.equals(SPARQLResultSetCSV) ) return readerCSV ;
if ( lang.equals(SPARQLResultSetTSV) ) return readerTSV ;
if ( lang.equals(SPARQLResultSetThrift) ) return readerThrift ;
throw new RiotException("Lang not registered (ResultSet reader)") ;
}
}
private static class ResultSetReaderThriftFactory implements ResultSetReaderFactory {
@Override
public ResultSetReader create(Lang lang) {
return new ResultSetReader() {
@Override
public ResultSet read(InputStream in, Context context) {
return BinRDF.readResultSet(in) ;
}
@Override
public ResultSet read(Reader in, Context context) {
throw new NotImplemented("Reading binary data from a java.io.Reader is not possible") ;
}} ;
}
}
// These all call static methods, so have no state and so don't
// need to be created for each read operation.
private static ResultSetReader readerXML = new ResultSetReader() {
@Override public ResultSet read(InputStream in, Context context) { return XMLInput.fromXML(in); }
@Override public ResultSet read(Reader in, Context context) { return XMLInput.fromXML(in); }
} ;
private static ResultSetReader readerJSON = new ResultSetReader() {
@Override public ResultSet read(InputStream in, Context context) { return JSONInput.fromJSON(in) ; }
@Override public ResultSet read(Reader in, Context context) { throw new NotImplemented("Reader") ; }
} ;
private static ResultSetReader readerCSV = new ResultSetReader() {
@Override public ResultSet read(InputStream in, Context context) { return CSVInput.fromCSV(in) ; }
@Override public ResultSet read(Reader in, Context context) { throw new NotImplemented("Reader") ; }
} ;
private static ResultSetReader readerTSV = new ResultSetReader() {
@Override public ResultSet read(InputStream in, Context context) { return TSVInput.fromTSV(in); }
@Override public ResultSet read(Reader in, Context context) { throw new NotImplemented("Reader") ; }
} ;
private static ResultSetReader readerThrift = new ResultSetReader() {
@Override public ResultSet read(InputStream in, Context context) { return BinRDF.readResultSet(in) ;}
@Override public ResultSet read(Reader in, Context context) {
throw new NotImplemented("Reading binary data from a java.io.Reader is not possible") ;
}
} ;
private static ResultSetReader readerNo = new ResultSetReader() {
@Override public ResultSet read(InputStream in, Context context) { return null ; }
@Override public ResultSet read(Reader in, Context context) { return null ; }
} ;
}