org.springframework.jdbc.core

## Class ColumnMapRowMapper

- java.lang.Object
- - org.springframework.jdbc.core.ColumnMapRowMapper

- All Implemented Interfaces:
    RowMapper<Map<String,Object>>

      public class ColumnMapRowMapper
      extends Object
      implements RowMapper<Map<String,Object>>

  `RowMapper` implementation that creates a `java.util.Map` for each row, representing all columns as key-value pairs: one entry for each column, with the column name as key.

  The Map implementation to use and the key to use for each column in the column Map can be customized through overriding `createColumnMap(int)` and `getColumnKey(java.lang.String)`, respectively.

  Note: 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.

  Since:
    1.2
  Author:
    Juergen Hoeller
  See Also:
    `JdbcTemplate.queryForList(String)`, `JdbcTemplate.queryForMap(String)`

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `ColumnMapRowMapper()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `protected Map<String,Object>` | `createColumnMap(int columnCount)` Create a Map instance to be used as column map.
    `protected String` | `getColumnKey(String columnName)` Determine the key to use for the given column in the column Map.
    `protected Object` | `getColumnValue(ResultSet rs, int index)` Retrieve a JDBC object value for the specified column.
    `Map<String,Object>` | `mapRow(ResultSet rs, int rowNum)` Implementations must implement this method to map each row of data in the ResultSet.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### ColumnMapRowMapper

          public ColumnMapRowMapper()

  - ### Method Detail

    - #### mapRow

          public Map<String,Object> mapRow(ResultSet rs,
                                  int rowNum)
                                    throws SQLException

      Description copied from interface: `RowMapper`
      Implementations must implement this method to map each row of data in the ResultSet. This method should not call `next()` on the ResultSet; it is only supposed to map values of the current row.
      Specified by:
        `mapRow` in interface `RowMapper<Map<String,Object>>`
      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` - if a SQLException is encountered getting column values (that is, there's no need to catch SQLException)

    - #### createColumnMap

          protected Map<String,Object> createColumnMap(int columnCount)

      Create a Map instance to be used as column map.

      By default, a linked case-insensitive Map will be created.

      Parameters:
        `columnCount` - the column count, to be used as initial capacity for the Map
      Returns:
        the new Map instance
      See Also:
        `LinkedCaseInsensitiveMap`

    - #### getColumnKey

          protected String getColumnKey(String columnName)

      Determine the key to use for the given column in the column Map.
      Parameters:
        `columnName` - the column name as returned by the ResultSet
      Returns:
        the column key to use
      See Also:
        `ResultSetMetaData.getColumnName(int)`

    - #### getColumnValue

          protected Object getColumnValue(ResultSet rs,
                              int index)
                                   throws SQLException

      Retrieve a JDBC object value for the specified column.

      The default implementation uses the `getObject` method. Additionally, this implementation includes a "hack" to get around Oracle returning a non standard object for their TIMESTAMP datatype.

      Parameters:
        `rs` - is the ResultSet holding the data
        `index` - is the column index
      Returns:
        the Object returned
      Throws:
        `SQLException`
      See Also:
        `JdbcUtils.getResultSetValue(java.sql.ResultSet, int, java.lang.Class)`