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</code> implementation that converts the first
28 * <code>ResultSet</code> row into a <code>Map</code>. 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</code> 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</code> implementation
53 * to use when converting rows into Maps.
54 */
55 public MapHandler(RowProcessor convert) {
56 super();
57 this.convert = convert;
58 }
59
60 /**
61 * Converts the first row in the <code>ResultSet</code> into a
62 * <code>Map</code>.
63 * @param rs <code>ResultSet</code> to process.
64 * @return A <code>Map</code> with the values from the first row or
65 * <code>null</code> if there are no rows in the <code>ResultSet</code>.
66 *
67 * @throws SQLException if a database access error occurs
68 *
69 * @see org.apache.commons.dbutils.ResultSetHandler#handle(java.sql.ResultSet)
70 */
71 public Map<String,Object> handle(ResultSet rs) throws SQLException {
72 return rs.next() ? this.convert.toMap(rs) : null;
73 }
74
75 }