planetj.database.connection
Class DataEngineConnection

java.lang.Object
  |
  +--planetj.database.connection.DataEngineConnection

All Implemented Interfaces:

Connection

public final class DataEngineConnection

extends Object

implements Connection

A wrapper implementation of the Connection interface. The database specfic Connection object is contained within an instance of DataEngineConnection.

Field Summary

Fields inherited from interface java.sql.Connection

TRANSACTION_NONE, TRANSACTION_READ_COMMITTED, TRANSACTION_READ_UNCOMMITTED, TRANSACTION_REPEATABLE_READ, TRANSACTION_SERIALIZABLE

Constructor Summary

DataEngineConnection(String alias, Connection trueConnection)
Creates a new DataEngineConnection.

DataEngineConnection(String alias, Connection trueConnection, DataEngineConnectionPool pool, int conn_id)
Creates a new DataEngineConnection.

Method Summary

void	clearWarnings() Clears all warnings reported for this Connection object.
void	close() Returns this Connection to its pool if it came from a connection pool, or closes it if it didn't come from a connection pool.
void	commit() Makes all changes made since the previous commit/rollback permanent and releases any database locks currently held by the Connection.
Statement	createStatement() Creates a Statement object for sending SQL statements to the database.
Statement	createStatement(int resultSetType, int resultSetConcurrency) JDBC 2.0 Creates a Statement object that will generate ResultSet objects with the given type and concurrency.
String	getAlias() Gets this connection's system alias.
boolean	getAutoCommit() Gets the current auto-commit state.
String	getCatalog() Returns the Connection's current catalog name.
int	getConnectionID() Gets the connection ID
String	getConnectionPoolAlias() Gets the alias by which this connection's connection pool is known.
long	getLastUsed() Returns the last time that this connection was "used".
DatabaseMetaData	getMetaData() Gets the metadata regarding this connection's database.
int	getPreparedStatementCount()
List	getPreparedStatements() Gets the statements that have been prepared in this connection.
int	getTransactionIsolation() Gets this Connection's current transaction isolation level.
Map	getTypeMap() JDBC 2.0 Gets the type map object associated with this connection.
SQLWarning	getWarnings() Returns the first warning reported by calls on this Connection.
boolean	isClosed() Tests to see if a Connection is closed.
boolean	isReadOnly() Tests to see if the connection is in read-only mode.
String	nativeSQL(String sql) Converts the given SQL statement into the system's native SQL grammar.
CallableStatement	prepareCall(String sql) Creates a CallableStatement object for calling database stored procedures.
CallableStatement	prepareCall(String sql, int resultSetType, int resultSetConcurrency) JDBC 2.0 Creates a CallableStatement object that will generate ResultSet objects with the given type and concurrency.
PreparedStatement	prepareStatement(String sql) Creates a PreparedStatement object for sending parameterized SQL statements to the database.
PreparedStatement	prepareStatement(String sql, int resultSetType, int resultSetConcurrency) JDBC 2.0 Creates a PreparedStatement object that will generate ResultSet objects with the given type and concurrency.
void	queryExecuted(String sql, long begin, long time) Records a query that has executed, and the time it took to execute.
void	rollback() Drops all changes made since the previous commit/rollback and releases any database locks currently held by this Connection.
void	setAutoCommit(boolean autoCommit) Sets this connection's auto-commit mode.
void	setCatalog(String catalog) Sets a catalog name in order to select a subspace of this Connection's database in which to work.
void	setReadOnly(boolean readOnly) Puts this connection in read-only mode as a hint to enable database optimizations.
void	setTransactionIsolation(int level) Attempts to change the transaction isolation level to the one given.
void	setTypeMap(Map map) JDBC 2.0 Installs the given type map as the type map for this connection.
void	shutDown() This is an internal DataEngine method, and should not be invoked by applications Releases a Connection's database and JDBC resources immediately instead of waiting for them to be automatically released.
void	statementExecuted(String sql, long begin, long time) Records the execution of a SQL statement
String	toString() Returns the Connection's alias.
void	updateExecuted(String sql, long begin, long time) Records an update that has executed, and the time it took to execute.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.sql.Connection

createStatement, getHoldability, prepareCall, prepareStatement, prepareStatement, prepareStatement, prepareStatement, releaseSavepoint, rollback, setHoldability, setSavepoint, setSavepoint

Constructor Detail

DataEngineConnection

public DataEngineConnection(String alias,
                            Connection trueConnection)
                     throws DataEngineException

Creates a new DataEngineConnection. This constructor is used when the DataEngine is passed a Connection which does not orginate from the DatabaseManager

DataEngineConnection

public DataEngineConnection(String alias,
                            Connection trueConnection,
                            DataEngineConnectionPool pool,
                            int conn_id)

Creates a new DataEngineConnection. This method is invoked from within a connection pool when a new connection need to be instantiated.

Method Detail

clearWarnings

public void clearWarnings()
                   throws SQLException

Clears all warnings reported for this Connection object. After a call to this method, the method getWarnings returns null until a new warning is reported for this Connection.

Specified by:

clearWarnings in interface Connection

Throws:

SQLException - if a database access error occurs

close

public void close()
           throws SQLException

Returns this Connection to its pool if it came from a connection pool, or closes it if it didn't come from a connection pool.

Specified by:

close in interface Connection

Throws:

SQLException - if a database access error occurs

commit

public void commit()
            throws SQLException

Makes all changes made since the previous commit/rollback permanent and releases any database locks currently held by the Connection. This method should be used only when auto-commit mode has been disabled.

Specified by:

commit in interface Connection

Throws:

SQLException - if a database access error occurs

See Also:

setAutoCommit(boolean)

createStatement

public Statement createStatement()
                          throws SQLException

Creates a Statement object for sending SQL statements to the database. SQL statements without parameters are normally executed using Statement objects. If the same SQL statement is executed many times, it is more efficient to use a PreparedStatement JDBC 2.0 Result sets created using the returned Statement will have forward-only type, and read-only concurrency, by default.

Specified by:

createStatement in interface Connection

Returns:

a new Statement object

Throws:

SQLException - if a database access error occurs

createStatement

public Statement createStatement(int resultSetType,
                                 int resultSetConcurrency)
                          throws SQLException

JDBC 2.0 Creates a Statement object that will generate ResultSet objects with the given type and concurrency. This method is the same as the createStatement method above, but it allows the default result set type and result set concurrency type to be overridden.

Specified by:

createStatement in interface Connection

Parameters:

resultSetType - a result set type; see ResultSet.TYPE_XXX

resultSetConcurrency - a concurrency type; see ResultSet.CONCUR_XXX

Returns:

a new Statement object

Throws:

SQLException - if a database access error occurs

getAlias

public String getAlias()

Gets this connection's system alias. This is the shared alias which corresponds to this connection; it may be different than the personal alias.

getAutoCommit

public boolean getAutoCommit()
                      throws SQLException

Gets the current auto-commit state.

Specified by:

getAutoCommit in interface Connection

Returns:

the current state of auto-commit mode

Throws:

SQLException - if a database access error occurs

See Also:

setAutoCommit(boolean)

getCatalog

public String getCatalog()
                  throws SQLException

Returns the Connection's current catalog name.

Specified by:

getCatalog in interface Connection

Returns:

the current catalog name or null

Throws:

SQLException - if a database access error occurs

getConnectionID

public int getConnectionID()

Gets the connection ID

getLastUsed

public long getLastUsed()

Returns the last time that this connection was "used".

Returns:

long

getMetaData

public DatabaseMetaData getMetaData()
                             throws SQLException

Gets the metadata regarding this connection's database. A Connection's database is able to provide information describing its tables, its supported SQL grammar, its stored procedures, the capabilities of this connection, and so on. This information is made available through a DatabaseMetaData object.

Specified by:

getMetaData in interface Connection

Returns:

a DatabaseMetaData object for this Connection

Throws:

SQLException - if a database access error occurs

getPreparedStatementCount

public int getPreparedStatementCount()

getPreparedStatements

public List getPreparedStatements()

Gets the statements that have been prepared in this connection. The List contains PreparedStatementCache.OrderedStringMapping objects. The sql field holds the String from which the statement was prepared; the time field holds the time that prepared statement was last accessed.

This method is for debugging/performance monitoring only; it should not be used as part of the normal DataEngine operations.

getTransactionIsolation

public int getTransactionIsolation()
                            throws SQLException

Gets this Connection's current transaction isolation level.

Specified by:

getTransactionIsolation in interface Connection

Returns:

the current TRANSACTION_* mode value

Throws:

SQLException - if a database access error occurs

getTypeMap

public Map getTypeMap()
               throws SQLException

JDBC 2.0 Gets the type map object associated with this connection. Unless the application has added an entry to the type map, the map returned will be empty.

Specified by:

getTypeMap in interface Connection

Returns:

the java.util.Map object associated with this Connection object

SQLException

getWarnings

public SQLWarning getWarnings()
                       throws SQLException

Returns the first warning reported by calls on this Connection.

Note: Subsequent warnings will be chained to this SQLWarning.

Specified by:

getWarnings in interface Connection

Returns:

the first SQLWarning or null

Throws:

SQLException - if a database access error occurs

isClosed

public boolean isClosed()
                 throws SQLException

Tests to see if a Connection is closed.

Specified by:

isClosed in interface Connection

Returns:

true if the connection is closed; false if it's still open

Throws:

SQLException - if a database access error occurs

isReadOnly

public boolean isReadOnly()
                   throws SQLException

Tests to see if the connection is in read-only mode.

Specified by:

isReadOnly in interface Connection

Returns:

true if connection is read-only and false otherwise

Throws:

SQLException - if a database access error occurs

nativeSQL

public String nativeSQL(String sql)
                 throws SQLException

Converts the given SQL statement into the system's native SQL grammar. A driver may convert the JDBC sql grammar into its system's native SQL grammar prior to sending it; this method returns the native form of the statement that the driver would have sent.

Specified by:

nativeSQL in interface Connection

Parameters:

sql - a SQL statement that may contain one or more '?' parameter placeholders

Returns:

the native form of this statement

Throws:

SQLException - if a database access error occurs

prepareCall

public CallableStatement prepareCall(String sql)
                              throws SQLException

Creates a CallableStatement object for calling database stored procedures. The CallableStatement provides methods for setting up its IN and OUT parameters, and methods for executing the call to a stored procedure.

Note: This method is optimized for handling stored procedure call statements. Some drivers may send the call statement to the database when the method prepareCall is done; others may wait until the CallableStatement is executed. This has no direct effect on users; however, it does affect which method throws certain SQLExceptions. JDBC 2.0 Result sets created using the returned CallableStatement will have forward-only type and read-only concurrency, by default.

Specified by:

prepareCall in interface Connection

Parameters:

sql - a SQL statement that may contain one or more '?' parameter placeholders. Typically this statement is a JDBC function call escape string.

Returns:

a new CallableStatement object containing the pre-compiled SQL statement

Throws:

SQLException - if a database access error occurs

prepareCall

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

JDBC 2.0 Creates a CallableStatement object that will generate ResultSet objects with the given type and concurrency. This method is the same as the prepareCall method above, but it allows the default result set type and result set concurrency type to be overridden.

Specified by:

prepareCall in interface Connection

Parameters:

resultSetType - a result set type; see ResultSet.TYPE_XXX

resultSetConcurrency - a concurrency type; see ResultSet.CONCUR_XXX

Returns:

a new CallableStatement object containing the pre-compiled SQL statement

Throws:

SQLException - if a database access error occurs

prepareStatement

public PreparedStatement prepareStatement(String sql)
                                   throws SQLException

Creates a PreparedStatement object for sending parameterized SQL statements to the database. A SQL statement with or without IN parameters can be pre-compiled and stored in a PreparedStatement object. This object can then be used to efficiently execute this statement multiple times.

Note: This method is optimized for handling parametric SQL statements that benefit from precompilation. If the driver supports precompilation, the method prepareStatement will send the statement to the database for precompilation. Some drivers may not support precompilation. In this case, the statement may not be sent to the database until the PreparedStatement is executed. This has no direct effect on users; however, it does affect which method throws certain SQLExceptions. JDBC 2.0 Result sets created using the returned PreparedStatement will have forward-only type and read-only concurrency, by default.

Specified by:

prepareStatement in interface Connection

Parameters:

sql - a SQL statement that may contain one or more '?' IN parameter placeholders

Returns:

a new PreparedStatement object containing the pre-compiled statement

Throws:

SQLException - if a database access error occurs

prepareStatement

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

JDBC 2.0 Creates a PreparedStatement object that will generate ResultSet objects with the given type and concurrency. This method is the same as the prepareStatement method above, but it allows the default result set type and result set concurrency type to be overridden.

Specified by:

prepareStatement in interface Connection

Parameters:

resultSetType - a result set type; see ResultSet.TYPE_XXX

resultSetConcurrency - a concurrency type; see ResultSet.CONCUR_XXX

Returns:

a new PreparedStatement object containing the pre-compiled SQL statement

Throws:

SQLException - if a database access error occurs

queryExecuted

public void queryExecuted(String sql,
                          long begin,
                          long time)

Records a query that has executed, and the time it took to execute.

Parameters:

sql - The sql statement that was executed.

begin - When the query was initiated

time - The time it took to execute. This should be less than 0 if and only if the query execution failed.

rollback

public void rollback()
              throws SQLException

Drops all changes made since the previous commit/rollback and releases any database locks currently held by this Connection. This method should be used only when auto- commit has been disabled.

Specified by:

rollback in interface Connection

Throws:

SQLException - if a database access error occurs

See Also:

setAutoCommit(boolean)

setAutoCommit

public void setAutoCommit(boolean autoCommit)
                   throws SQLException

Sets this connection's auto-commit mode. If a connection is in auto-commit mode, then all its SQL statements will be executed and committed as individual transactions. Otherwise, its SQL statements are grouped into transactions that are terminated by a call to either the method commit or the method rollback. By default, new connections are in auto-commit mode. The commit occurs when the statement completes or the next execute occurs, whichever comes first. In the case of statements returning a ResultSet, the statement completes when the last row of the ResultSet has been retrieved or the ResultSet has been closed. In advanced cases, a single statement may return multiple results as well as output parameter values. In these cases the commit occurs when all results and output parameter values have been retrieved.

Specified by:

setAutoCommit in interface Connection

Parameters:

autoCommit - true enables auto-commit; false disables auto-commit.

Throws:

SQLException - if a database access error occurs

setCatalog

public void setCatalog(String catalog)
                throws SQLException

Sets a catalog name in order to select a subspace of this Connection's database in which to work. If the driver does not support catalogs, it will silently ignore this request.

Specified by:

setCatalog in interface Connection

Throws:

SQLException - if a database access error occurs

setReadOnly

public void setReadOnly(boolean readOnly)
                 throws SQLException

Puts this connection in read-only mode as a hint to enable database optimizations.

Note: This method cannot be called while in the middle of a transaction.

Specified by:

setReadOnly in interface Connection

Parameters:

readOnly - true enables read-only mode; false disables read-only mode.

Throws:

SQLException - if a database access error occurs

setTransactionIsolation

public void setTransactionIsolation(int level)
                             throws SQLException

Attempts to change the transaction isolation level to the one given. The constants defined in the interface Connection are the possible transaction isolation levels.

Note: This method cannot be called while in the middle of a transaction.

Specified by:

setTransactionIsolation in interface Connection

Parameters:

level - one of the TRANSACTION_* isolation values with the exception of TRANSACTION_NONE; some databases may not support other values

Throws:

SQLException - if a database access error occurs

See Also:

DatabaseMetaData.supportsTransactionIsolationLevel(int)

setTypeMap

public void setTypeMap(Map map)
                throws SQLException

JDBC 2.0 Installs the given type map as the type map for this connection. The type map will be used for the custom mapping of SQL structured types and distinct types.

Specified by:

setTypeMap in interface Connection

SQLException

shutDown

public void shutDown()
              throws SQLException

This is an internal DataEngine method, and should not be invoked by applications

Releases a Connection's database and JDBC resources immediately instead of waiting for them to be automatically released.

Note: A Connection is automatically closed when it is garbage collected. Certain fatal errors also result in a closed Connection.

Throws:

SQLException - if a database access error occurs

statementExecuted

public void statementExecuted(String sql,
                              long begin,
                              long time)

Records the execution of a SQL statement

Parameters:

sql - The sql statement that was executed.

begin - When the execution was initiated

time - The time it took to execute. This should be less than 0 if and only if the execution failed.

toString

public String toString()

Returns the Connection's alias.

Overrides:

toString in class Object

updateExecuted

public void updateExecuted(String sql,
                           long begin,
                           long time)

Records an update that has executed, and the time it took to execute.

Parameters:

sql - The sql statement that was executed.

begin - When the update was initiated

time - The time it took to execute. This should be less than 0 if and only if the update execution failed.

getConnectionPoolAlias

public String getConnectionPoolAlias()

Gets the alias by which this connection's connection pool is known. This will be the same as the this connection's personal system alias. It may be different than the shared alias