jena-arq/src/main/java/org/apache/jena/sparql/resultset/ResultSetApply.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 org.apache.jena.sparql.resultset;

import org.apache.jena.query.QuerySolution;
import org.apache.jena.query.ResultSet;
import org.apache.jena.rdf.model.RDFNode;

/** A class to walk a result set. */

public class ResultSetApply {
    ResultSetProcessor proc = null;
    ResultSet          rs   = null;

    public ResultSetApply(ResultSet rs, ResultSetProcessor proc) {
        this.proc = proc;
        this.rs = rs;
    }

    public void apply() {
        proc.start(rs);
        for ( ; rs.hasNext() ; ) {
            QuerySolution qs = rs.next();
            proc.start(qs);
            for ( String varName : rs.getResultVars() ) {
                RDFNode node = qs.get(varName);
                // node may be null
                proc.binding(varName, node);
            }
            proc.finish(qs);
        }
        proc.finish(rs);
    }

    public static void apply(ResultSet rs, ResultSetProcessor proc) {
        ResultSetApply rsa = new ResultSetApply(rs, proc);
        rsa.apply();
    }
}