Package org.springframework.jdbc.core
Class RowMapperResultSetExtractor<T>
- java.lang.Object
- org.springframework.jdbc.core.RowMapperResultSetExtractor<T>
- All Implemented Interfaces:
ResultSetExtractor<List<T>>
public class RowMapperResultSetExtractor<T> extends Object implements ResultSetExtractor<List<T>>
Adapter implementation of the ResultSetExtractor interface that delegates to a RowMapper which is supposed to create an object for each row. Each object is added to the results List of this ResultSetExtractor.Useful for the typical case of one object per row in the database table. The number of entries in the results list will match the number of rows.
Note that a RowMapper object is typically stateless and thus reusable; just the RowMapperResultSetExtractor adapter is stateful.
A usage example with JdbcTemplate:
JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource); // reusable object RowMapper rowMapper = new UserRowMapper(); // reusable object List allUsers = (List) jdbcTemplate.query( "select * from user", new RowMapperResultSetExtractor(rowMapper, 10)); User user = (User) jdbcTemplate.queryForObject( "select * from user where id=?", new Object[] {id}, new RowMapperResultSetExtractor(rowMapper, 1));
Alternatively, consider subclassing MappingSqlQuery from the
jdbc.object
package: Instead of working with separate JdbcTemplate and RowMapper objects, you can have executable query objects (containing row-mapping logic) there.- Since:
- 1.0.2
- Author:
- Juergen Hoeller
- See Also:
RowMapper
,JdbcTemplate
,MappingSqlQuery
Constructor Summary
Constructors Constructor Description RowMapperResultSetExtractor(RowMapper<T> rowMapper)
Create a new RowMapperResultSetExtractor.RowMapperResultSetExtractor(RowMapper<T> rowMapper, int rowsExpected)
Create a new RowMapperResultSetExtractor.
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description List<T>
extractData(ResultSet rs)
Implementations must implement this method to process the entire ResultSet.
Constructor Detail
RowMapperResultSetExtractor
public RowMapperResultSetExtractor(RowMapper<T> rowMapper)
Create a new RowMapperResultSetExtractor.- Parameters:
rowMapper
- the RowMapper which creates an object for each row
RowMapperResultSetExtractor
public RowMapperResultSetExtractor(RowMapper<T> rowMapper, int rowsExpected)
Create a new RowMapperResultSetExtractor.- Parameters:
rowMapper
- the RowMapper which creates an object for each rowrowsExpected
- the number of expected rows (just used for optimized collection handling)
Method Detail
extractData
public List<T> extractData(ResultSet rs) throws SQLException
Description copied from interface:ResultSetExtractor
Implementations must implement this method to process the entire ResultSet.- Specified by:
extractData
in interfaceResultSetExtractor<T>
- Parameters:
rs
- ResultSet to extract data from. Implementations should not close this: it will be closed by the calling JdbcTemplate.- Returns:
- an arbitrary result object, or
null
if none (the extractor will typically be stateful in the latter case). - Throws:
SQLException
- if a SQLException is encountered getting column values or navigating (that is, there's no need to catch SQLException)