org.datanucleus.store.rdbms.datasource.dbcp

Class PoolingConnection

java.lang.Object

org.datanucleus.store.rdbms.datasource.dbcp.AbandonedTrace

org.datanucleus.store.rdbms.datasource.dbcp.DelegatingConnection

org.datanucleus.store.rdbms.datasource.dbcp.PoolingConnection

All Implemented Interfaces:

AutoCloseable, Connection, Wrapper, KeyedPoolableObjectFactory

public class PoolingConnection
extends DelegatingConnection
implements Connection, KeyedPoolableObjectFactory

A DelegatingConnection that pools PreparedStatements.

The prepareStatement(java.lang.String) and prepareCall(java.lang.String) methods, rather than creating a new PreparedStatement each time, may actually pull the statement from a pool of unused statements. The Statement.close() method of the returned statement doesn't actually close the statement, but rather returns it to the pool. (See PoolablePreparedStatement, PoolableCallableStatement.)

Version:

$Revision: 885261 $ $Date: 2009-11-29 15:07:02 -0500 (Sun, 29 Nov 2009) $

Author:

Rodney Waldhoff, Dirk Verbeeck

See Also:

PoolablePreparedStatement

Field Summary

Fields

Modifier and Type	Field and Description
protected KeyedObjectPool	_pstmtPool Pool of PreparedStatements.

Fields inherited from class org.datanucleus.store.rdbms.datasource.dbcp.DelegatingConnection

_closed, _conn

Fields inherited from interface java.sql.Connection

TRANSACTION_NONE, TRANSACTION_READ_COMMITTED, TRANSACTION_READ_UNCOMMITTED, TRANSACTION_REPEATABLE_READ, TRANSACTION_SERIALIZABLE

Constructor Summary

Constructors

Constructor and Description
PoolingConnection(Connection c) Constructor.
PoolingConnection(Connection c, KeyedObjectPool pool) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	activateObject(Object key, Object obj) KeyedPoolableObjectFactory method for activating pooled statements.
void	close() Close and free all PreparedStatements or CallableStatement from the pool, and close the underlying connection.
protected Object	createKey(String sql) Create a PStmtKey for the given arguments.
protected Object	createKey(String sql, byte stmtType) Create a PStmtKey for the given arguments.
protected Object	createKey(String sql, int resultSetType, int resultSetConcurrency) Create a PStmtKey for the given arguments.
protected Object	createKey(String sql, int resultSetType, int resultSetConcurrency, byte stmtType) Create a PStmtKey for the given arguments.
void	destroyObject(Object key, Object obj) KeyedPoolableObjectFactory method for destroying PoolablePreparedStatements and PoolableCallableStatements.
Object	makeObject(Object obj) KeyedPoolableObjectFactory method for creating PoolablePreparedStatements or PoolableCallableStatements.
protected String	normalizeSQL(String sql) Normalize the given SQL statement, producing a cannonical form that is semantically equivalent to the original.
void	passivateObject(Object key, Object obj) KeyedPoolableObjectFactory method for passivating PreparedStatements or CallableStatements.
CallableStatement	prepareCall(String sql) Create or obtain a CallableStatement from the pool.
CallableStatement	prepareCall(String sql, int resultSetType, int resultSetConcurrency) Create or obtain a CallableStatement from the pool.
PreparedStatement	prepareStatement(String sql) Create or obtain a PreparedStatement from the pool.
PreparedStatement	prepareStatement(String sql, int resultSetType, int resultSetConcurrency) Create or obtain a PreparedStatement from the pool.
String	toString() Returns a string representation of the metadata associated with the innnermost delegate connection.
boolean	validateObject(Object key, Object obj) KeyedPoolableObjectFactory method for validating pooled statements.

Methods inherited from class org.datanucleus.store.rdbms.datasource.dbcp.DelegatingConnection

abort, activate, checkOpen, clearWarnings, commit, createArrayOf, createBlob, createClob, createNClob, createSQLXML, createStatement, createStatement, createStatement, createStruct, equals, getAutoCommit, getCatalog, getClientInfo, getClientInfo, getDelegate, getDelegateInternal, getHoldability, getInnermostDelegate, getInnermostDelegateInternal, getMetaData, getNetworkTimeout, getSchema, getTransactionIsolation, getTypeMap, getWarnings, handleException, hashCode, innermostDelegateEquals, isClosed, isReadOnly, isValid, isWrapperFor, nativeSQL, passivate, prepareCall, prepareStatement, prepareStatement, prepareStatement, prepareStatement, releaseSavepoint, rollback, rollback, setAutoCommit, setCatalog, setClientInfo, setClientInfo, setDelegate, setHoldability, setNetworkTimeout, setReadOnly, setSavepoint, setSavepoint, setSchema, setTransactionIsolation, setTypeMap, unwrap

Methods inherited from class org.datanucleus.store.rdbms.datasource.dbcp.AbandonedTrace

addTrace, clearTrace, getConfig, getLastUsed, getTrace, printStackTrace, removeTrace, setLastUsed, setLastUsed, setStackTrace

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.sql.Connection

abort, clearWarnings, commit, createArrayOf, createBlob, createClob, createNClob, createSQLXML, createStatement, createStatement, createStatement, createStruct, getAutoCommit, getCatalog, getClientInfo, getClientInfo, getHoldability, getMetaData, getNetworkTimeout, getSchema, getTransactionIsolation, getTypeMap, getWarnings, isClosed, isReadOnly, isValid, nativeSQL, prepareCall, prepareStatement, prepareStatement, prepareStatement, prepareStatement, releaseSavepoint, rollback, rollback, setAutoCommit, setCatalog, setClientInfo, setClientInfo, setHoldability, setNetworkTimeout, setReadOnly, setSavepoint, setSavepoint, setSchema, setTransactionIsolation, setTypeMap

Methods inherited from interface java.sql.Wrapper

isWrapperFor, unwrap

Field Detail

_pstmtPool

protected KeyedObjectPool _pstmtPool

Pool of PreparedStatements. and CallableStatements

Constructor Detail

PoolingConnection

public PoolingConnection(Connection c)

Constructor.

Parameters:

c - the underlying Connection.

PoolingConnection

public PoolingConnection(Connection c,
                 KeyedObjectPool pool)

Constructor.

Parameters:

c - the underlying Connection.

pool - KeyedObjectPool of PreparedStatements and CallableStatements.

Method Detail

close

public void close()
           throws SQLException

Close and free all PreparedStatements or CallableStatement from the pool, and close the underlying connection.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Connection

Overrides:

close in class DelegatingConnection

Throws:

SQLException

prepareStatement

public PreparedStatement prepareStatement(String sql)
                                   throws SQLException

Create or obtain a PreparedStatement from the pool.

Specified by:

prepareStatement in interface Connection

Overrides:

prepareStatement in class DelegatingConnection

Parameters:

sql - the sql string used to define the PreparedStatement

Returns:

a PoolablePreparedStatement

Throws:

SQLException

prepareStatement

public PreparedStatement prepareStatement(String sql,
                                 int resultSetType,
                                 int resultSetConcurrency)
                                   throws SQLException

Create or obtain a PreparedStatement from the pool.

Specified by:

prepareStatement in interface Connection

Overrides:

prepareStatement in class DelegatingConnection

Parameters:

sql - the sql string used to define the PreparedStatement

resultSetType - result set type

resultSetConcurrency - result set concurrency

Returns:

a PoolablePreparedStatement

Throws:

SQLException

prepareCall

public CallableStatement prepareCall(String sql)
                              throws SQLException

Create or obtain a CallableStatement from the pool.

Specified by:

prepareCall in interface Connection

Overrides:

prepareCall in class DelegatingConnection

Parameters:

sql - the sql string used to define the CallableStatement

Returns:

a PoolableCallableStatement

Throws:

SQLException

Since:

1.3

prepareCall

public CallableStatement prepareCall(String sql,
                            int resultSetType,
                            int resultSetConcurrency)
                              throws SQLException

Create or obtain a CallableStatement from the pool.

Specified by:

prepareCall in interface Connection

Overrides:

prepareCall in class DelegatingConnection

Parameters:

sql - the sql string used to define the CallableStatement

resultSetType - result set type

resultSetConcurrency - result set concurrency

Returns:

a PoolableCallableStatement

Throws:

SQLException

Since:

1.3

createKey

protected Object createKey(String sql,
               int resultSetType,
               int resultSetConcurrency)

Create a PStmtKey for the given arguments.

Parameters:

sql - the sql string used to define the statement

resultSetType - result set type

resultSetConcurrency - result set concurrency

createKey

protected Object createKey(String sql,
               int resultSetType,
               int resultSetConcurrency,
               byte stmtType)

Create a PStmtKey for the given arguments.

Parameters:

sql - the sql string used to define the statement

resultSetType - result set type

resultSetConcurrency - result set concurrency

stmtType - statement type - either STATEMENT_CALLABLESTMT or STATEMENT_PREPAREDSTMT

createKey

protected Object createKey(String sql)

Create a PStmtKey for the given arguments.

Parameters:

sql - the sql string used to define the statement

createKey

protected Object createKey(String sql,
               byte stmtType)

Create a PStmtKey for the given arguments.

Parameters:

sql - the sql string used to define the statement

stmtType - statement type - either STATEMENT_CALLABLESTMT or STATEMENT_PREPAREDSTMT

normalizeSQL

protected String normalizeSQL(String sql)

Normalize the given SQL statement, producing a cannonical form that is semantically equivalent to the original.

makeObject

public Object makeObject(Object obj)
                  throws Exception

KeyedPoolableObjectFactory method for creating PoolablePreparedStatements or PoolableCallableStatements. The stmtType field in the key determines whether a PoolablePreparedStatement or PoolableCallableStatement is created.

Specified by:

makeObject in interface KeyedPoolableObjectFactory

Parameters:

obj - the key for the PreparedStatement to be created

Returns:

an instance that can be served by the pool.

Throws:

Exception - if there is a problem creating a new instance, this will be propagated to the code requesting an object.

See Also:

createKey(String, int, int, byte)

destroyObject

public void destroyObject(Object key,
                 Object obj)
                   throws Exception

KeyedPoolableObjectFactory method for destroying PoolablePreparedStatements and PoolableCallableStatements. Closes the underlying statement.

Specified by:

destroyObject in interface KeyedPoolableObjectFactory

Parameters:

key - ignored

obj - the pooled statement to be destroyed.

Throws:

Exception - should be avoided as it may be swallowed by the pool implementation.

See Also:

KeyedPoolableObjectFactory.validateObject(java.lang.Object, java.lang.Object), KeyedObjectPool.invalidateObject(java.lang.Object, java.lang.Object)

validateObject

public boolean validateObject(Object key,
                     Object obj)

KeyedPoolableObjectFactory method for validating pooled statements. Currently always returns true.

Specified by:

validateObject in interface KeyedPoolableObjectFactory

Parameters:

key - ignored

obj - ignored

Returns:

true

activateObject

public void activateObject(Object key,
                  Object obj)
                    throws Exception

KeyedPoolableObjectFactory method for activating pooled statements.

Specified by:

activateObject in interface KeyedPoolableObjectFactory

Parameters:

key - ignored

obj - pooled statement to be activated

Throws:

Exception - if there is a problem activating obj, this exception may be swallowed by the pool.

See Also:

KeyedPoolableObjectFactory.destroyObject(java.lang.Object, java.lang.Object)

passivateObject

public void passivateObject(Object key,
                   Object obj)
                     throws Exception

KeyedPoolableObjectFactory method for passivating PreparedStatements or CallableStatements. Invokes PreparedStatement.clearParameters().

Specified by:

passivateObject in interface KeyedPoolableObjectFactory

Parameters:

key - ignored

obj - a PreparedStatement

Throws:

Exception - if there is a problem passivating obj, this exception may be swallowed by the pool.

See Also:

KeyedPoolableObjectFactory.destroyObject(java.lang.Object, java.lang.Object)

toString

public String toString()

Description copied from class: DelegatingConnection

Returns a string representation of the metadata associated with the innnermost delegate connection.

Overrides:

toString in class DelegatingConnection