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NativeJdbcExtractorAdapter (Spring Framework) - Spring Framework 1.2.9 API 文档英文版


org.springframework.jdbc.support.nativejdbc
Class NativeJdbcExtractorAdapter

java.lang.Object
  extended by org.springframework.jdbc.support.nativejdbc.NativeJdbcExtractorAdapter
All Implemented Interfaces:
NativeJdbcExtractor
Direct Known Subclasses:
C3P0NativeJdbcExtractor, CommonsDbcpNativeJdbcExtractor, JBossNativeJdbcExtractor, SimpleNativeJdbcExtractor, WebLogicNativeJdbcExtractor, WebSphereNativeJdbcExtractor, XAPoolNativeJdbcExtractor

public abstract class NativeJdbcExtractorAdapter
extends Object
implements NativeJdbcExtractor

Abstract adapter class for the NativeJdbcExtractor interface, for simplified implementation of basic extractors. Basically returns the passed-in JDBC objects on all methods.

getNativeConnection checks for a ConnectionProxy chain, for example from a TransactionAwareDataSourceProxy, before delegating to doGetNativeConnection for actual unwrapping. You can override either of the two for a specific connection pool, but the latter is recommended to participate in ConnectionProxy unwrapping.

getNativeConnection also applies a fallback if the first native extraction process failed, that is, returned the same Connection as passed in. It assumes that some additional proxying is going in this case: Hence, it retrieves the underlying native Connection from the DatabaseMetaData via conHandle.getMetaData().getConnection() and retries the native extraction process based on that Connection handle. This works, for example, for the Connection proxies exposed by Hibernate 3.1's Session.connection().

The getNativeConnectionFromStatement method is implemented to simply delegate to getNativeConnection with the Statement's Connection. This is what most extractor implementations will stick to, unless there's a more efficient version for a specific pool.

Since:
1.1
Author:
Juergen Hoeller
See Also:
getNativeConnection(java.sql.Connection), getNativeConnectionFromStatement(java.sql.Statement), ConnectionProxy

Constructor Summary
NativeJdbcExtractorAdapter()
           
 
Method Summary
protected  Connection doGetNativeConnection(Connection con)
          Not able to unwrap: return passed-in Connection.
 CallableStatement getNativeCallableStatement(CallableStatement cs)
          Not able to unwrap: return passed-in CallableStatement.
 Connection getNativeConnection(Connection con)
          Check for a ConnectionProxy chain, then delegate to doGetNativeConnection.
 Connection getNativeConnectionFromStatement(Statement stmt)
          Retrieve the Connection via the Statement's Connection.
 PreparedStatement getNativePreparedStatement(PreparedStatement ps)
          Not able to unwrap: return passed-in PreparedStatement.
 ResultSet getNativeResultSet(ResultSet rs)
          Not able to unwrap: return passed-in ResultSet.
 Statement getNativeStatement(Statement stmt)
          Not able to unwrap: return passed-in Statement.
 boolean isNativeConnectionNecessaryForNativeCallableStatements()
          Return false by default.
 boolean isNativeConnectionNecessaryForNativePreparedStatements()
          Return false by default.
 boolean isNativeConnectionNecessaryForNativeStatements()
          Return false by default.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

NativeJdbcExtractorAdapter

public NativeJdbcExtractorAdapter()
Method Detail

isNativeConnectionNecessaryForNativeStatements

public boolean isNativeConnectionNecessaryForNativeStatements()
Return false by default.

Specified by:
isNativeConnectionNecessaryForNativeStatements in interface NativeJdbcExtractor

isNativeConnectionNecessaryForNativePreparedStatements

public boolean isNativeConnectionNecessaryForNativePreparedStatements()
Return false by default.

Specified by:
isNativeConnectionNecessaryForNativePreparedStatements in interface NativeJdbcExtractor

isNativeConnectionNecessaryForNativeCallableStatements

public boolean isNativeConnectionNecessaryForNativeCallableStatements()
Return false by default.

Specified by:
isNativeConnectionNecessaryForNativeCallableStatements in interface NativeJdbcExtractor

getNativeConnection

public Connection getNativeConnection(Connection con)
                               throws SQLException
Check for a ConnectionProxy chain, then delegate to doGetNativeConnection.

ConnectionProxy is used by Spring's TransactionAwareDataSourceProxy and LazyConnectionDataSourceProxy. The target connection behind it is typically one from a local connection pool, to be unwrapped by the doGetNativeConnection implementation of a concrete subclass.

Specified by:
getNativeConnection in interface NativeJdbcExtractor
Parameters:
con - the Connection handle, potentially wrapped by a connection pool
Returns:
the underlying native JDBC Connection, if possible; else, the original Connection
Throws:
SQLException - if thrown by JDBC methods
See Also:
doGetNativeConnection(java.sql.Connection), ConnectionProxy, DataSourceUtils.getTargetConnection(java.sql.Connection), TransactionAwareDataSourceProxy, LazyConnectionDataSourceProxy

doGetNativeConnection

protected Connection doGetNativeConnection(Connection con)
                                    throws SQLException
Not able to unwrap: return passed-in Connection.

Throws:
SQLException

getNativeConnectionFromStatement

public Connection getNativeConnectionFromStatement(Statement stmt)
                                            throws SQLException
Retrieve the Connection via the Statement's Connection.

Specified by:
getNativeConnectionFromStatement in interface NativeJdbcExtractor
Parameters:
stmt - the Statement handle, potentially wrapped by a connection pool
Returns:
the underlying native JDBC Connection, if possible; else, the original Connection
Throws:
SQLException - if thrown by JDBC methods
See Also:
getNativeConnection(java.sql.Connection), Statement.getConnection()

getNativeStatement

public Statement getNativeStatement(Statement stmt)
                             throws SQLException
Not able to unwrap: return passed-in Statement.

Specified by:
getNativeStatement in interface NativeJdbcExtractor
Parameters:
stmt - the Statement handle, potentially wrapped by a connection pool
Returns:
the underlying native JDBC Statement, if possible; else, the original Connection
Throws:
SQLException - if thrown by JDBC methods

getNativePreparedStatement

public PreparedStatement getNativePreparedStatement(PreparedStatement ps)
                                             throws SQLException
Not able to unwrap: return passed-in PreparedStatement.

Specified by:
getNativePreparedStatement in interface NativeJdbcExtractor
Parameters:
ps - the PreparedStatement handle, potentially wrapped by a connection pool
Returns:
the underlying native JDBC PreparedStatement, if possible; else, the original Connection
Throws:
SQLException - if thrown by JDBC methods

getNativeCallableStatement

public CallableStatement getNativeCallableStatement(CallableStatement cs)
                                             throws SQLException
Not able to unwrap: return passed-in CallableStatement.

Specified by:
getNativeCallableStatement in interface NativeJdbcExtractor
Parameters:
cs - the CallableStatement handle, potentially wrapped by a connection pool
Returns:
the underlying native JDBC CallableStatement, if possible; else, the original Connection
Throws:
SQLException - if thrown by JDBC methods

getNativeResultSet

public ResultSet getNativeResultSet(ResultSet rs)
                             throws SQLException
Not able to unwrap: return passed-in ResultSet.

Specified by:
getNativeResultSet in interface NativeJdbcExtractor
Parameters:
rs - the ResultSet handle, potentially wrapped by a connection pool
Returns:
the underlying native JDBC ResultSet, if possible; else, the original Connection
Throws:
SQLException - if thrown by JDBC methods


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