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     */
017    package org.apache.commons.dbutils.handlers;
018    
019    import java.sql.ResultSet;
020    import java.sql.SQLException;
021    
022    import org.apache.commons.dbutils.BasicRowProcessor;
023    import org.apache.commons.dbutils.ResultSetHandler;
024    import org.apache.commons.dbutils.RowProcessor;
025    
026    /**
027     * <code>ResultSetHandler</code> implementation that converts a
028     * <code>ResultSet</code> into an <code>Object[]</code>. This class is
029     * thread safe.
030     *
031     * @see org.apache.commons.dbutils.ResultSetHandler
032     */
033    public class ArrayHandler implements ResultSetHandler<Object[]> {
034    
035        /**
036         * Singleton processor instance that handlers share to save memory.  Notice
037         * the default scoping to allow only classes in this package to use this
038         * instance.
039         */
040        static final RowProcessor ROW_PROCESSOR = new BasicRowProcessor();
041    
042        /**
043         * The RowProcessor implementation to use when converting rows
044         * into arrays.
045         */
046        private final RowProcessor convert;
047    
048        /**
049         * Creates a new instance of ArrayHandler using a
050         * <code>BasicRowProcessor</code> for conversion.
051         */
052        public ArrayHandler() {
053            this(ROW_PROCESSOR);
054        }
055    
056        /**
057         * Creates a new instance of ArrayHandler.
058         *
059         * @param convert The <code>RowProcessor</code> implementation
060         * to use when converting rows into arrays.
061         */
062        public ArrayHandler(RowProcessor convert) {
063            super();
064            this.convert = convert;
065        }
066    
067        /**
068         * Places the column values from the first row in an <code>Object[]</code>.
069         * @param rs <code>ResultSet</code> to process.
070         * @return An Object[] or <code>null</code> if there are no rows in the
071         * <code>ResultSet</code>.
072         *
073         * @throws SQLException if a database access error occurs
074         * @see org.apache.commons.dbutils.ResultSetHandler#handle(java.sql.ResultSet)
075         */
076        public Object[] handle(ResultSet rs) throws SQLException {
077            return rs.next() ? this.convert.toArray(rs) : null;
078        }
079    
080    }