org.apache.derby.client.am
Class LogicalStatementEntity

java.lang.Object
  org.apache.derby.client.am.LogicalStatementEntity

All Implemented Interfaces:

java.sql.Statement, java.sql.Wrapper

Direct Known Subclasses:

LogicalPreparedStatement

abstract class LogicalStatementEntity
extends java.lang.Object
implements java.sql.Statement

Common class interacting with the JDBC statement cache for logical prepared statements and logical callable statements.

Note that getPhysPs() and getPhysCs() takes care of checking if the logical statement has been closed. The physical statement will take care of validating itself.

Beside from the above, special treatment of logical entities happens on close. This is the point where cache interaction takes place, and also where the appropriate methods are called on the physical statement to perform the necessary clean up for later reuse.

A note regarding the thread safety of this class, is that access to physicalPs and physicalCs is guarded by the instance of this class, but it is assumed that operation on/within the physical statement is synchronized in the physical statement itself .

Field Summary

private JDBCStatementCache	cache Cache for physical statements.
private boolean	hasCallableStmt Tells if we're holding a callable statement or not.
private StatementCacheInteractor	owner The owner of this logical entity.
private java.sql.CallableStatement	physicalCs Assoicated physical callable statement, if any.
private java.sql.PreparedStatement	physicalPs Associated physical prepared statement.
private StatementKey	stmtKey The key for the associated statement.

Fields inherited from interface java.sql.Statement

CLOSE_ALL_RESULTS, CLOSE_CURRENT_RESULT, EXECUTE_FAILED, KEEP_CURRENT_RESULT, NO_GENERATED_KEYS, RETURN_GENERATED_KEYS, SUCCESS_NO_INFO

Constructor Summary

protected

LogicalStatementEntity(java.sql.PreparedStatement physicalPs, StatementKey stmtKey, StatementCacheInteractor cacheInteractor) Create a logical entity for a PreparedStatement.

Method Summary

void	close() Close the logical statement.
void	closeOnCompletion()
long[]	executeLargeBatch()
long	executeLargeUpdate(java.lang.String sql)
long	executeLargeUpdate(java.lang.String sql, int autoGeneratedKeys)
long	executeLargeUpdate(java.lang.String sql, int[] columnIndexes)
long	executeLargeUpdate(java.lang.String sql, java.lang.String[] columnNames)
long	getLargeMaxRows()
long	getLargeUpdateCount()
(package private) java.sql.CallableStatement	getPhysCs() Returns the associated physical callable statement.
(package private) java.sql.PreparedStatement	getPhysPs() Returns the associated physical prepared statement.
(package private) java.sql.Statement	getPhysStmt() Returns the associated physical statement.
boolean	isCloseOnCompletion()
(package private) boolean	isLogicalEntityClosed() Tells if the logical entity is closed.
boolean	isWrapperFor(java.lang.Class<?> iface) Check whether this instance wraps an object that implements the interface specified by iface.
void	setLargeMaxRows(long maxRows)
<T> T	unwrap(java.lang.Class<T> iface) Returns an instance of the specified interface if this instance is a wrapper for the interface.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.sql.Statement

addBatch, cancel, clearBatch, clearWarnings, execute, execute, execute, execute, executeBatch, executeQuery, executeUpdate, executeUpdate, executeUpdate, executeUpdate, getConnection, getFetchDirection, getFetchSize, getGeneratedKeys, getMaxFieldSize, getMaxRows, getMoreResults, getMoreResults, getQueryTimeout, getResultSet, getResultSetConcurrency, getResultSetHoldability, getResultSetType, getUpdateCount, getWarnings, isClosed, isPoolable, setCursorName, setEscapeProcessing, setFetchDirection, setFetchSize, setMaxFieldSize, setMaxRows, setPoolable, setQueryTimeout

Field Detail

hasCallableStmt

private final boolean hasCallableStmt

Tells if we're holding a callable statement or not.

Used for sanity checking.

physicalPs

private java.sql.PreparedStatement physicalPs

Associated physical prepared statement.

If this is null, the logical entity is closed.

physicalCs

private java.sql.CallableStatement physicalCs

Assoicated physical callable statement, if any.

This is a convenience reference, to avoid having to cast on every invokation of getPhysCs() if the logical entity represents a callable statement.

owner

private StatementCacheInteractor owner

The owner of this logical entity.

stmtKey

private final StatementKey stmtKey

The key for the associated statement.

cache

private final JDBCStatementCache cache

Cache for physical statements.

Constructor Detail

LogicalStatementEntity

protected LogicalStatementEntity(java.sql.PreparedStatement physicalPs,
                                 StatementKey stmtKey,
                                 StatementCacheInteractor cacheInteractor)

Create a logical entity for a PreparedStatement.

Parameters:

physicalPs - a physical PreparedStatement

stmtKey - cache key for the physical statement

cacheInteractor - creating statement cache interactor

Throws:

java.lang.IllegalArgumentException - if cache is null

Method Detail

getPhysPs

java.sql.PreparedStatement getPhysPs()
                               throws java.sql.SQLException

Returns the associated physical prepared statement.

Returns:

A prepared statement.

Throws:

java.sql.SQLException - if the logical statement has been closed

getPhysCs

java.sql.CallableStatement getPhysCs()
                               throws java.sql.SQLException

Returns the associated physical callable statement.

Returns:

A callable statement.

Throws:

java.sql.SQLException - if the logical statement has been closed

getPhysStmt

java.sql.Statement getPhysStmt()
                         throws java.sql.SQLException

Returns the associated physical statement.

Returns:

A statement.

Throws:

java.sql.SQLException - if the logical statement has been closed

close

public void close()
           throws java.sql.SQLException

Close the logical statement.

Specified by:

close in interface java.sql.Statement

Throws:

java.sql.SQLException - if closing the statement fails

isLogicalEntityClosed

boolean isLogicalEntityClosed()

Tells if the logical entity is closed.

If this method is used to avoid the possibility of raising an exception because the logical statement has been closed and then invoke a method on the physical statement, one must synchronize on this instance in the calling code.

Returns:

true if closed, false if open.

isWrapperFor

public boolean isWrapperFor(java.lang.Class<?> iface)
                     throws java.sql.SQLException

Check whether this instance wraps an object that implements the interface specified by iface.

Specified by:

isWrapperFor in interface java.sql.Wrapper

Parameters:

iface - a class defining an interface

Returns:

true if this instance implements iface, or false otherwise

Throws:

java.sql.SQLException - if an error occurs while determining if this instance implements iface

unwrap

public <T> T unwrap(java.lang.Class<T> iface)
         throws java.sql.SQLException

Returns an instance of the specified interface if this instance is a wrapper for the interface.

Specified by:

unwrap in interface java.sql.Wrapper

Parameters:

iface - a class defining an interface

Returns:

an object that implements the interface

Throws:

java.sql.SQLException - if no object is found that implements the interface

closeOnCompletion

public void closeOnCompletion()
                       throws java.sql.SQLException

Throws:

java.sql.SQLException

isCloseOnCompletion

public boolean isCloseOnCompletion()
                            throws java.sql.SQLException

Throws:

java.sql.SQLException

executeLargeBatch

public long[] executeLargeBatch()
                         throws java.sql.SQLException

Throws:

java.sql.SQLException

executeLargeUpdate

public long executeLargeUpdate(java.lang.String sql)
                        throws java.sql.SQLException

Throws:

java.sql.SQLException

executeLargeUpdate

public long executeLargeUpdate(java.lang.String sql,
                               int autoGeneratedKeys)
                        throws java.sql.SQLException

Throws:

java.sql.SQLException

executeLargeUpdate

public long executeLargeUpdate(java.lang.String sql,
                               int[] columnIndexes)
                        throws java.sql.SQLException

Throws:

java.sql.SQLException

executeLargeUpdate

public long executeLargeUpdate(java.lang.String sql,
                               java.lang.String[] columnNames)
                        throws java.sql.SQLException

Throws:

java.sql.SQLException

getLargeUpdateCount

public long getLargeUpdateCount()
                         throws java.sql.SQLException

Throws:

java.sql.SQLException

getLargeMaxRows

public long getLargeMaxRows()
                     throws java.sql.SQLException

Throws:

java.sql.SQLException

setLargeMaxRows

public void setLargeMaxRows(long maxRows)
                     throws java.sql.SQLException

Throws:

java.sql.SQLException