/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.jdbc.core;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.Map;
import org.springframework.core.CollectionFactory;
import org.springframework.jdbc.support.JdbcUtils;
/**
* {@link RowMapper} implementation that creates a <code>java.util.Map</code>
* for each row, representing all columns as key-value pairs: one
* entry for each column, with the column name as key.
*
* <p>The Map implementation to use and the key to use for each column
* in the column Map can be customized through overriding
* {@link #createColumnMap} and {@link #getColumnKey}, respectively.
*
* <p><b>Note:</b> By default, ColumnMapRowMapper will try to build a linked Map
* with case-insensitive keys, to preserve column order as well as allow any
* casing to be used for column names. This requires Commons Collections on the
* classpath (which will be autodetected). Else, the fallback is a standard linked
* HashMap, which will still preserve column order but requires the application
* to specify the column names in the same casing as exposed by the driver.
*
* @author Juergen Hoeller
* @since 1.2
* @see JdbcTemplate#queryForList(String)
* @see JdbcTemplate#queryForMap(String)
*/
public class ColumnMapRowMapper implements RowMapper {
public Object mapRow(ResultSet rs, int rowNum) throws SQLException {
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
Map mapOfColValues = createColumnMap(columnCount);
for (int i = 1; i <= columnCount; i++) {
String key = getColumnKey(JdbcUtils.lookupColumnName(rsmd, i));
Object obj = getColumnValue(rs, i);
mapOfColValues.put(key, obj);
}
return mapOfColValues;
}
/**
* Create a Map instance to be used as column map.
* <p>By default, a linked case-insensitive Map will be created if possible,
* else a plain HashMap (see Spring's CollectionFactory).
* @param columnCount the column count, to be used as initial
* capacity for the Map
* @return the new Map instance
* @see org.springframework.core.CollectionFactory#createLinkedCaseInsensitiveMapIfPossible
*/
protected Map createColumnMap(int columnCount) {
return CollectionFactory.createLinkedCaseInsensitiveMapIfPossible(columnCount);
}
/**
* Determine the key to use for the given column in the column Map.
* @param columnName the column name as returned by the ResultSet
* @return the column key to use
* @see java.sql.ResultSetMetaData#getColumnName
*/
protected String getColumnKey(String columnName) {
return columnName;
}
/**
* Retrieve a JDBC object value for the specified column.
* <p>The default implementation uses the <code>getObject</code> method.
* Additionally, this implementation includes a "hack" to get around Oracle
* returning a non standard object for their TIMESTAMP datatype.
* @param rs is the ResultSet holding the data
* @param index is the column index
* @return the Object returned
* @see org.springframework.jdbc.support.JdbcUtils#getResultSetValue
*/
protected Object getColumnValue(ResultSet rs, int index) throws SQLException {
return JdbcUtils.getResultSetValue(rs, index);
}
}