    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.dbutils.handlers;
    018
    019import java.sql.ResultSet;
    020import java.sql.SQLException;
    021import java.util.Map;
    022
    023import org.apache.commons.dbutils.ResultSetHandler;
    024import org.apache.commons.dbutils.RowProcessor;
    025
    026/**
    027 * {@code ResultSetHandler} implementation that converts the first
    028 * {@code ResultSet} row into a {@code Map}. This class is thread
    029 * safe.
    030 *
    031 * @see org.apache.commons.dbutils.ResultSetHandler
    032 */
    033public class MapHandler implements ResultSetHandler<Map<String, Object>> {
    034
    035    /**
    036     * The RowProcessor implementation to use when converting rows
    037     * into Maps.
    038     */
    039    private final RowProcessor convert;
    040
    041    /**
    042     * Creates a new instance of MapHandler using a
    043     * {@code BasicRowProcessor} for conversion.
    044     */
    045    public MapHandler() {
    046        this(ArrayHandler.ROW_PROCESSOR);
    047    }
    048
    049    /**
    050     * Creates a new instance of MapHandler.
    051     *
    052     * @param convert The {@code RowProcessor} implementation
    053     * to use when converting rows into Maps.
    054     */
    055    public MapHandler(final RowProcessor convert) {
    056        this.convert = convert;
    057    }
    058
    059    /**
    060     * Converts the first row in the {@code ResultSet} into a
    061     * {@code Map}.
    062     * @param resultSet {@code ResultSet} to process.
    063     * @return A {@code Map} with the values from the first row or
    064     * {@code null} if there are no rows in the {@code ResultSet}.
    065     *
    066     * @throws SQLException if a database access error occurs
    067     *
    068     * @see org.apache.commons.dbutils.ResultSetHandler#handle(java.sql.ResultSet)
    069     */
    070    @Override
    071    public Map<String, Object> handle(final ResultSet resultSet) throws SQLException {
    072        return resultSet.next() ? this.convert.toMap(resultSet) : null;
    073    }
    074
    075}