public class

SingleColumnRowMapper

extends Object
implements RowMapper<T>
java.lang.Object
   ↳ org.springframework.jdbc.core.SingleColumnRowMapper<T>
Known Direct Subclasses

Class Overview

RowMapper implementation that converts a single column into a single result value per row. Expects to operate on a java.sql.ResultSet that just contains a single column.

The type of the result value for each row can be specified. The value for the single column will be extracted from the ResultSet and converted into the specified target type.

See Also

Summary

Public Constructors
SingleColumnRowMapper()
Create a new SingleColumnRowMapper.
SingleColumnRowMapper(Class<T> requiredType)
Create a new SingleColumnRowMapper.
Public Methods
T mapRow(ResultSet rs, int rowNum)
Extract a value for the single column in the current row.
void setRequiredType(Class<T> requiredType)
Set the type that each result object is expected to match.
Protected Methods
Object convertValueToRequiredType(Object value, Class requiredType)
Convert the given column value to the specified required type.
Object getColumnValue(ResultSet rs, int index)
Retrieve a JDBC object value for the specified column, using the most appropriate value type.
Object getColumnValue(ResultSet rs, int index, Class requiredType)
Retrieve a JDBC object value for the specified column.
[Expand]
Inherited Methods
From class java.lang.Object
From interface org.springframework.jdbc.core.RowMapper

Public Constructors

public SingleColumnRowMapper ()

Create a new SingleColumnRowMapper.

See Also

public SingleColumnRowMapper (Class<T> requiredType)

Create a new SingleColumnRowMapper.

Parameters
requiredType the type that each result object is expected to match

Public Methods

public T mapRow (ResultSet rs, int rowNum)

Extract a value for the single column in the current row.

Validates that there is only one column selected, then delegates to getColumnValue() and also convertValueToRequiredType, if necessary.

Parameters
rs the ResultSet to map (pre-initialized for the current row)
rowNum the number of the current row
Returns
  • the result object for the current row
Throws
SQLException
See Also

public void setRequiredType (Class<T> requiredType)

Set the type that each result object is expected to match.

If not specified, the column value will be exposed as returned by the JDBC driver.

Protected Methods

protected Object convertValueToRequiredType (Object value, Class requiredType)

Convert the given column value to the specified required type. Only called if the extracted column value does not match already.

If the required type is String, the value will simply get stringified via toString(). In case of a Number, the value will be converted into a Number, either through number conversion or through String parsing (depending on the value type).

Parameters
value the column value as extracted from getColumnValue() (never null)
requiredType the type that each result object is expected to match (never null)
Returns
  • the converted value
See Also

protected Object getColumnValue (ResultSet rs, int index)

Retrieve a JDBC object value for the specified column, using the most appropriate value type. Called if no required type has been specified.

The default implementation delegates to JdbcUtils.getResultSetValue(), which uses the ResultSet.getObject(index) method. Additionally, it includes a "hack" to get around Oracle returning a non-standard object for their TIMESTAMP datatype. See the JdbcUtils#getResultSetValue() javadoc for details.

Parameters
rs is the ResultSet holding the data
index is the column index
Returns
  • the Object value
Throws
SQLException in case of extraction failure
See Also

protected Object getColumnValue (ResultSet rs, int index, Class requiredType)

Retrieve a JDBC object value for the specified column.

The default implementation calls getResultSetValue(java.sql.ResultSet, int, Class). If no required type has been specified, this method delegates to getColumnValue(rs, index), which basically calls ResultSet.getObject(index) but applies some additional default conversion to appropriate value types.

Parameters
rs is the ResultSet holding the data
index is the column index
requiredType the type that each result object is expected to match (or null if none specified)
Returns
  • the Object value
Throws
SQLException in case of extraction failure
See Also