1 /*
2 * Copyright 2002-2012 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.jdbc.core;
18
19 import java.sql.ResultSet;
20 import java.sql.ResultSetMetaData;
21 import java.sql.SQLException;
22 import java.util.Map;
23
24 import org.springframework.jdbc.support.JdbcUtils;
25 import org.springframework.util.LinkedCaseInsensitiveMap;
26
27 /**
28 * {@link RowMapper} implementation that creates a {@code java.util.Map}
29 * for each row, representing all columns as key-value pairs: one
30 * entry for each column, with the column name as key.
31 *
32 * <p>The Map implementation to use and the key to use for each column
33 * in the column Map can be customized through overriding
34 * {@link #createColumnMap} and {@link #getColumnKey}, respectively.
35 *
36 * <p><b>Note:</b> By default, ColumnMapRowMapper will try to build a linked Map
37 * with case-insensitive keys, to preserve column order as well as allow any
38 * casing to be used for column names. This requires Commons Collections on the
39 * classpath (which will be autodetected). Else, the fallback is a standard linked
40 * HashMap, which will still preserve column order but requires the application
41 * to specify the column names in the same casing as exposed by the driver.
42 *
43 * @author Juergen Hoeller
44 * @since 1.2
45 * @see JdbcTemplate#queryForList(String)
46 * @see JdbcTemplate#queryForMap(String)
47 */
48 public class ColumnMapRowMapper implements RowMapper<Map<String, Object>> {
49
50 @Override
51 public Map<String, Object> mapRow(ResultSet rs, int rowNum) throws SQLException {
52 ResultSetMetaData rsmd = rs.getMetaData();
53 int columnCount = rsmd.getColumnCount();
54 Map<String, Object> mapOfColValues = createColumnMap(columnCount);
55 for (int i = 1; i <= columnCount; i++) {
56 String key = getColumnKey(JdbcUtils.lookupColumnName(rsmd, i));
57 Object obj = getColumnValue(rs, i);
58 mapOfColValues.put(key, obj);
59 }
60 return mapOfColValues;
61 }
62
63 /**
64 * Create a Map instance to be used as column map.
65 * <p>By default, a linked case-insensitive Map will be created.
66 * @param columnCount the column count, to be used as initial
67 * capacity for the Map
68 * @return the new Map instance
69 * @see org.springframework.util.LinkedCaseInsensitiveMap
70 */
71 protected Map<String, Object> createColumnMap(int columnCount) {
72 return new LinkedCaseInsensitiveMap<Object>(columnCount);
73 }
74
75 /**
76 * Determine the key to use for the given column in the column Map.
77 * @param columnName the column name as returned by the ResultSet
78 * @return the column key to use
79 * @see java.sql.ResultSetMetaData#getColumnName
80 */
81 protected String getColumnKey(String columnName) {
82 return columnName;
83 }
84
85 /**
86 * Retrieve a JDBC object value for the specified column.
87 * <p>The default implementation uses the {@code getObject} method.
88 * Additionally, this implementation includes a "hack" to get around Oracle
89 * returning a non standard object for their TIMESTAMP datatype.
90 * @param rs is the ResultSet holding the data
91 * @param index is the column index
92 * @return the Object returned
93 * @see org.springframework.jdbc.support.JdbcUtils#getResultSetValue
94 */
95 protected Object getColumnValue(ResultSet rs, int index) throws SQLException {
96 return JdbcUtils.getResultSetValue(rs, index);
97 }
98
99 }