1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.dbutils.handlers;
18
19 import java.sql.ResultSet;
20 import java.sql.SQLException;
21 import java.util.Map;
22
23 import org.apache.commons.dbutils.ResultSetHandler;
24 import org.apache.commons.dbutils.RowProcessor;
25
26 /**
27 * {@code ResultSetHandler} implementation that converts the first
28 * {@code ResultSet} row into a {@code Map}. This class is thread
29 * safe.
30 *
31 * @see org.apache.commons.dbutils.ResultSetHandler
32 */
33 public class MapHandler implements ResultSetHandler<Map<String, Object>> {
34
35 /**
36 * The RowProcessor implementation to use when converting rows
37 * into Maps.
38 */
39 private final RowProcessor convert;
40
41 /**
42 * Creates a new instance of MapHandler using a
43 * {@code BasicRowProcessor} for conversion.
44 */
45 public MapHandler() {
46 this(ArrayHandler.ROW_PROCESSOR);
47 }
48
49 /**
50 * Creates a new instance of MapHandler.
51 *
52 * @param convert The {@code RowProcessor} implementation
53 * to use when converting rows into Maps.
54 */
55 public MapHandler(final RowProcessor convert) {
56 this.convert = convert;
57 }
58
59 /**
60 * Converts the first row in the {@code ResultSet} into a
61 * {@code Map}.
62 * @param resultSet {@code ResultSet} to process.
63 * @return A {@code Map} with the values from the first row or
64 * {@code null} if there are no rows in the {@code ResultSet}.
65 *
66 * @throws SQLException if a database access error occurs
67 *
68 * @see org.apache.commons.dbutils.ResultSetHandler#handle(java.sql.ResultSet)
69 */
70 @Override
71 public Map<String, Object> handle(final ResultSet resultSet) throws SQLException {
72 return resultSet.next() ? this.convert.toMap(resultSet) : null;
73 }
74
75 }