Class StatementCacheInteractor

java.lang.Object

org.apache.derby.client.am.StatementCacheInteractor

public final class StatementCacheInteractor
extends Object

Utility class encapsulating the logic for interacting with the JDBC statement cache when creating new logical statements.

This class was introduced to share code between the pre-JDBC 4 and the JDBC 4+ versions of the JDBC classes.

The pattern for the prepareX methods is:

1. Generate a key for the statement to create.
2. Consult cache to see if an existing statement can be used.
3. Create new statement on physical connection if necessary.
4. Return reference to existing or newly created statement.

Field Summary

Fields

Modifier and Type	Field	Description
private final JDBCStatementCache	cache	Statement cache for the associated physical connection.
private boolean	connCloseInProgress	Tells if this interactor is in the process of shutting down.
private final ArrayList<LogicalStatementEntity>	openLogicalStatements	List of open logical statements created by this cache interactor.
private final ClientConnection	physicalConnection	The underlying physical connection.

Constructor Summary

Constructors

Constructor	Description
StatementCacheInteractor(JDBCStatementCache cache, ClientConnection physicalConnection)	Creates a new JDBC statement cache interactor.

Method Summary

Modifier and Type	Method	Description
(package private) void	closeOpenLogicalStatements()	Closes all open logical statements created by this cache interactor.
private CallableStatement	createLogicalCallableStatement(CallableStatement cs, StatementKey stmtKey)	Creates a logical callable statement.
private PreparedStatement	createLogicalPreparedStatement(PreparedStatement ps, StatementKey stmtKey)	Creates a logical prepared statement.
(package private) JDBCStatementCache	getCache()	Returns the associated statement cache.
(package private) void	markClosed(LogicalStatementEntity logicalStmt)	Designates the specified logical statement as closed.
(package private) CallableStatement	prepareCall(String sql)
(package private) CallableStatement	prepareCall(String sql, int resultSetType, int resultSetConcurrency)
(package private) CallableStatement	prepareCall(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability)
(package private) PreparedStatement	prepareStatement(String sql)
(package private) PreparedStatement	prepareStatement(String sql, int autoGeneratedKeys)
(package private) PreparedStatement	prepareStatement(String sql, int resultSetType, int resultSetConcurrency)
(package private) PreparedStatement	prepareStatement(String sql, int resultSetType, int resultSetConcurrency, int resultSetHoldability)

Methods inherited from class Object

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

Field Details

cache

private final JDBCStatementCache cache

Statement cache for the associated physical connection.

physicalConnection

private final ClientConnection physicalConnection

The underlying physical connection.

Note that it is the responsibility of the logical statement assoiciated with this cache interactor to ensure the interactor methods are not invoked if the logical statement has been closed.

openLogicalStatements

private final ArrayList<LogicalStatementEntity> openLogicalStatements

List of open logical statements created by this cache interactor.

connCloseInProgress

private boolean connCloseInProgress

Tells if this interactor is in the process of shutting down.

If this is true, it means that the logical connection is being closed.

Constructor Details

StatementCacheInteractor

StatementCacheInteractor(JDBCStatementCache cache,
 ClientConnection physicalConnection)

Creates a new JDBC statement cache interactor.

Parameters:

cache - statement cache

physicalConnection - associated physical connection

Method Details

prepareStatement

PreparedStatement prepareStatement(String sql)
                            throws SQLException

Throws:

SQLException

See Also:

• Connection.prepareStatement(String)

prepareStatement

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

Throws:

SQLException

See Also:

• Connection.prepareStatement(String,int,int)

prepareStatement

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

Throws:

SQLException

See Also:

• Connection.prepareStatement(String,int,int,int)

prepareStatement

PreparedStatement prepareStatement(String sql,
 int autoGeneratedKeys)
                            throws SQLException

Throws:

SQLException

See Also:

• Connection.prepareStatement(String,int)

prepareCall

CallableStatement prepareCall(String sql)
                       throws SQLException

Throws:

SQLException

See Also:

• Connection.prepareCall(String)

prepareCall

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

Throws:

SQLException

See Also:

• Connection.prepareCall(String,int,int)

prepareCall

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

Throws:

SQLException

See Also:

• Connection.prepareCall(String,int,int,int)

closeOpenLogicalStatements

void closeOpenLogicalStatements()
                         throws SQLException

Closes all open logical statements created by this cache interactor.

A cache interactor is bound to a single (caching) logical connection.

Throws:

SQLException - if closing an open logical connection fails

markClosed

void markClosed(LogicalStatementEntity logicalStmt)

Designates the specified logical statement as closed.

Parameters:

logicalStmt - the logical statement being closed

createLogicalPreparedStatement

private PreparedStatement createLogicalPreparedStatement(PreparedStatement ps,
 StatementKey stmtKey)
                                                  throws SQLException

Creates a logical prepared statement.

Parameters:

ps - the underlying physical prepared statement

stmtKey - the statement key for the physical statement

Returns:

A logical prepared statement.

Throws:

SQLException - if creating a logical prepared statement fails

createLogicalCallableStatement

private CallableStatement createLogicalCallableStatement(CallableStatement cs,
 StatementKey stmtKey)
                                                  throws SQLException

Creates a logical callable statement.

Parameters:

cs - the underlying physical callable statement

stmtKey - the statement key for the physical statement

Returns:

A logical callable statement.

Throws:

SQLException - if creating a logical callable statement fails

getCache

JDBCStatementCache getCache()

Returns the associated statement cache.

Returns:

A statement cache.