所有已知实现类:
C3P0NativeJdbcExtractor, CommonsDbcpNativeJdbcExtractor, JBossNativeJdbcExtractor, Jdbc4NativeJdbcExtractor, NativeJdbcExtractorAdapter, OracleJdbc4NativeJdbcExtractor, SimpleNativeJdbcExtractor, WebLogicNativeJdbcExtractor, WebSphereNativeJdbcExtractor
```
public interface NativeJdbcExtractor
```
Interface for extracting native JDBC objects from wrapped objects coming from connection pools. This is necessary to allow for casting to native implementations like OracleConnection or OracleResultSet in application code, for example to create Blobs or to access vendor-specific features.
Note: Setting a custom NativeJdbcExtractor is just necessary if you intend to cast to database-specific implementations like OracleConnection or OracleResultSet. Otherwise, any wrapped JDBC object will be fine, with no need for unwrapping.
Note: To be able to support any pool's strategy of native ResultSet wrapping, it is advisable to get both the native Statement and the native ResultSet via this extractor. Some pools just allow to unwrap the Statement, some just to unwrap the ResultSet - the above strategy will cover both. It is typically not necessary to unwrap the Connection to retrieve a native ResultSet.
When working with a simple connection pool that wraps Connections but not Statements, a SimpleNativeJdbcExtractor is often sufficient. However, some pools (like Apache's Commons DBCP) wrap all JDBC objects that they return: Therefore, you need to use a specific NativeJdbcExtractor (like CommonsDbcpNativeJdbcExtractor) with them.
JdbcTemplate can properly apply a NativeJdbcExtractor if specified, unwrapping all JDBC objects that it creates. Note that this is just necessary if you intend to cast to native implementations in your data access code.
OracleLobHandler, the Oracle-specific implementation of Spring's LobHandler interface, requires a NativeJdbcExtractor for obtaining the native OracleConnection. This is also necessary for other Oracle-specific features that you may want to leverage in your applications, such as Oracle InterMedia.
从以下版本开始:
25.08.2003
作者:
Juergen Hoeller
另请参阅:
SimpleNativeJdbcExtractor, CommonsDbcpNativeJdbcExtractor, JdbcTemplate.setNativeJdbcExtractor(org.springframework.jdbc.support.nativejdbc.NativeJdbcExtractor), OracleLobHandler.setNativeJdbcExtractor(org.springframework.jdbc.support.nativejdbc.NativeJdbcExtractor)

方法概要

所有方法实例方法抽象方法
修饰符和类型	方法	说明
`CallableStatement`	`getNativeCallableStatement(CallableStatement cs)`	Retrieve the underlying native JDBC CallableStatement for the given statement.
`Connection`	`getNativeConnection(Connection con)`	Retrieve the underlying native JDBC Connection for the given Connection.
`Connection`	`getNativeConnectionFromStatement(Statement stmt)`	Retrieve the underlying native JDBC Connection for the given Statement.
`PreparedStatement`	`getNativePreparedStatement(PreparedStatement ps)`	Retrieve the underlying native JDBC PreparedStatement for the given statement.
`ResultSet`	`getNativeResultSet(ResultSet rs)`	Retrieve the underlying native JDBC ResultSet for the given statement.
`Statement`	`getNativeStatement(Statement stmt)`	Retrieve the underlying native JDBC Statement for the given Statement.
`boolean`	`isNativeConnectionNecessaryForNativeCallableStatements()`	Return whether it is necessary to work on the native Connection to receive native CallableStatements.
`boolean`	`isNativeConnectionNecessaryForNativePreparedStatements()`	Return whether it is necessary to work on the native Connection to receive native PreparedStatements.
`boolean`	`isNativeConnectionNecessaryForNativeStatements()`	Return whether it is necessary to work on the native Connection to receive native Statements.

- 方法详细资料
  - isNativeConnectionNecessaryForNativeStatements
```
boolean isNativeConnectionNecessaryForNativeStatements()
```
    Return whether it is necessary to work on the native Connection to receive native Statements.
    This should be true if the connection pool does not allow to extract the native JDBC objects from its Statement wrapper but supports a way to retrieve the native JDBC Connection. This way, applications can still receive native Statements and ResultSet via working on the native JDBC Connection.
  - isNativeConnectionNecessaryForNativePreparedStatements
```
boolean isNativeConnectionNecessaryForNativePreparedStatements()
```
    Return whether it is necessary to work on the native Connection to receive native PreparedStatements.
    This should be true if the connection pool does not allow to extract the native JDBC objects from its PreparedStatement wrappers but supports a way to retrieve the native JDBC Connection. This way, applications can still receive native Statements and ResultSet via working on the native JDBC Connection.
  - isNativeConnectionNecessaryForNativeCallableStatements
```
boolean isNativeConnectionNecessaryForNativeCallableStatements()
```
    Return whether it is necessary to work on the native Connection to receive native CallableStatements.
    This should be true if the connection pool does not allow to extract the native JDBC objects from its CallableStatement wrappers but supports a way to retrieve the native JDBC Connection. This way, applications can still receive native Statements and ResultSet via working on the native JDBC Connection.
  - getNativeConnection
```
Connection getNativeConnection(Connection con)
                        throws SQLException
```
    Retrieve the underlying native JDBC Connection for the given Connection. Supposed to return the given Connection if not capable of unwrapping.
    参数:
    con - the Connection handle, potentially wrapped by a connection pool
    返回:
    the underlying native JDBC Connection, if possible; else, the original Connection
    抛出:
    SQLException - if thrown by JDBC methods
  - getNativeConnectionFromStatement
```
Connection getNativeConnectionFromStatement(Statement stmt)
                                     throws SQLException
```
    Retrieve the underlying native JDBC Connection for the given Statement. Supposed to return the Statement.getConnection() if not capable of unwrapping.
    Having this extra method allows for more efficient unwrapping if data access code already has a Statement. Statement.getConnection() often returns the native JDBC Connection even if the Statement itself is wrapped by a pool.
    参数:
    stmt - the Statement handle, potentially wrapped by a connection pool
    返回:
    the underlying native JDBC Connection, if possible; else, the original Connection
    抛出:
    SQLException - if thrown by JDBC methods
    另请参阅:
    Statement.getConnection()
  - getNativeStatement
```
Statement getNativeStatement(Statement stmt)
                      throws SQLException
```
    Retrieve the underlying native JDBC Statement for the given Statement. Supposed to return the given Statement if not capable of unwrapping.
    参数:
    stmt - the Statement handle, potentially wrapped by a connection pool
    返回:
    the underlying native JDBC Statement, if possible; else, the original Statement
    抛出:
    SQLException - if thrown by JDBC methods
  - getNativePreparedStatement
```
PreparedStatement getNativePreparedStatement(PreparedStatement ps)
                                      throws SQLException
```
    Retrieve the underlying native JDBC PreparedStatement for the given statement. Supposed to return the given PreparedStatement if not capable of unwrapping.
    参数:
    ps - the PreparedStatement handle, potentially wrapped by a connection pool
    返回:
    the underlying native JDBC PreparedStatement, if possible; else, the original PreparedStatement
    抛出:
    SQLException - if thrown by JDBC methods
  - getNativeCallableStatement
```
CallableStatement getNativeCallableStatement(CallableStatement cs)
                                      throws SQLException
```
    Retrieve the underlying native JDBC CallableStatement for the given statement. Supposed to return the given CallableStatement if not capable of unwrapping.
    参数:
    cs - the CallableStatement handle, potentially wrapped by a connection pool
    返回:
    the underlying native JDBC CallableStatement, if possible; else, the original CallableStatement
    抛出:
    SQLException - if thrown by JDBC methods
  - getNativeResultSet
```
ResultSet getNativeResultSet(ResultSet rs)
                      throws SQLException
```
    Retrieve the underlying native JDBC ResultSet for the given statement. Supposed to return the given ResultSet if not capable of unwrapping.
    参数:
    rs - the ResultSet handle, potentially wrapped by a connection pool
    返回:
    the underlying native JDBC ResultSet, if possible; else, the original ResultSet
    抛出:
    SQLException - if thrown by JDBC methods

接口 NativeJdbcExtractor

方法概要

方法详细资料

isNativeConnectionNecessaryForNativeStatements

isNativeConnectionNecessaryForNativePreparedStatements

isNativeConnectionNecessaryForNativeCallableStatements

getNativeConnection

getNativeConnectionFromStatement

getNativeStatement

getNativePreparedStatement

getNativeCallableStatement

getNativeResultSet