iudex.da.ContentReader.java Source code

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Here is the source code for iudex.da.ContentReader.java

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/*
 * Copyright (c) 2008-2012 David Kellum
 *
 * Licensed 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 iudex.da;

import iudex.core.VisitURL;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import javax.sql.DataSource;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;

import com.gravitext.htmap.UniMap;

public class ContentReader {
    public ContentReader(DataSource source, ContentMapper mapper) {
        _mapper = mapper;
        _dsource = source;
    }

    public ContentMapper mapper() {
        return _mapper;
    }

    public DataSource dataSource() {
        return _dsource;
    }

    public UniMap read(VisitURL url) throws SQLException {
        final StringBuilder qb = new StringBuilder(256);
        qb.append("SELECT ");
        mapper().appendFieldNames(qb);
        qb.append(" FROM urls WHERE uhash = ?;");

        List<UniMap> list = select(qb.toString(), url.uhash());

        if (list.size() == 1)
            return list.get(0);
        if (list.size() > 1) {
            throw new IllegalStateException("Multiple url rows returned for uhash=" + url.uhash());
        }
        return null;
    }

    public List<UniMap> select(String query, Object... params) throws SQLException {
        QueryRunner runner = new QueryRunner(_dsource);

        return runner.query(query, new MapHandler(), params);
    }

    protected final class MapHandler implements ResultSetHandler<List<UniMap>> {
        @Override
        public List<UniMap> handle(ResultSet rset) throws SQLException {
            ArrayList<UniMap> contents = new ArrayList<UniMap>(128);
            while (rset.next()) {
                contents.add(_mapper.fromResultSet(rset));
            }
            return contents;
        }

    }

    private final DataSource _dsource;
    private final ContentMapper _mapper;
}