com.objectwave.persist.broker
Class RDBConnection

java.lang.Object
  |
  +--com.objectwave.persist.broker.RDBConnection

Direct Known Subclasses:

OracleConnection

public class RDBConnection

extends java.lang.Object

A connection to the database. Used by the connection pool and the RDBBroker. A not null value for the system property ow.persistConnectionVerbose will result in details of the SQL being sent over this connection to be logged. There will only ever be one thread operating on a single instance of an RDBConnection. A violation of that assumption will destroy the thread safety of this class.

Version:

$Id: RDBConnection.java,v 2.5 2002/02/07 02:44:05 dave_hoag Exp $

Author:

Dave Hoag

Field Summary

protected int	cachedCount
protected SqlStatementCacheItem[]	cachedStatements
protected java.sql.Statement	cachedUpdateStmt
protected java.sql.Connection	connection
protected SqlConnectionFactory	connectionSource
protected java.lang.String	connectUrl
protected static boolean	doInsert
protected static java.lang.String	insrtProp
protected boolean	inTransaction
protected GrinderResultSet	lastResultSet
protected static boolean	manageTransaction If manageTransaction is false, no commit or rollback calls will ever be made.
protected static boolean	metrics
protected static java.lang.String	metricsProp
protected boolean	needsExplicitBegin
protected java.lang.Object[]	objArrays
protected java.lang.String	password
protected RDBConnectionPool	pool
protected ObjectPoolBroker	poolBroker
static int	sqlStatementCount Description of the Field
protected boolean	supportsTransaction
protected java.lang.Thread	thread
protected java.lang.String	userName
protected static boolean	verbose
protected static java.lang.String	verbProp

Method Summary

protected void	addStatement(SQLModifier modifier, java.lang.Class persistenceClass, java.sql.PreparedStatement stmt) Add a prepared statement to this connection's path.
void	alterVendorConnection(java.sql.Connection con) Callback hook from connectionSource to allow vendor specific modification to the connection object.
void	beginTransaction() If the database supports transactions this method would begin the transaction.
protected java.sql.Connection	checkConnection() Verify that there is already a connection to the relational database.
protected void	clearConnection() Only in the event of a very bad thing should this method be invoked.
void	commit() Issues a database Commit.
void	execSql(java.lang.String aString) Execute and finish.
java.util.List	executeQuery(java.lang.String aString, int numberOfColumns) Execute and finish.
protected void	finalize() Disconnect from database if not already done.
GrinderResultSet	findExecSql(SQLAssembler sqlObj) Used for executing any sql query statement.
GrinderResultSet	findExecSql(SQLAssembler sqlObj, boolean release) Used for executing any sql query statement.
void	freeConnection() Every connection is associated with a particular thread.
java.sql.DatabaseMetaData	getDatabaseMetaData()
protected SqlConnectionFactory	getDefaultConnectionSource()
GrinderResultSet	getLastResultSet() Gets the LastResultSet attribute of the RDBConnection object
protected java.lang.Object[]	getObjectArrays()
ObjectPoolBroker	getObjectPoolBroker() Every connection may end up manipulating the ObjectPool.
protected RDBConnectionPool	getPool() The associated connection pool of which this connection is a member.
java.lang.Thread	getThread() Get the thread that is currently related to this connection.
void	initialize(RDBConnectionPool pool, java.lang.String connectUrl, java.lang.String userName, java.lang.String password)
boolean	isInTransaction()
int	nextPrimaryKey(SQLSelect sqlA)
void	preparedUpdateSql(SQLModifier sqlObj, Persistence pObj) Execute java.sql.PreparedStatement code, perhaps creating the PreparedStatement object in the process.
void	rollback() Issues a database rollback.
void	setBrokerProperty(BrokerPropertyIF b) The ability to support properties other than System.getProperties();
protected void	setConnection(java.sql.Connection newValue) Change the connection to the new value.
void	setConnectionSource(SqlConnectionFactory factory) Allow brokers to change the connection factory.
void	setObjectPoolBroker(ObjectPoolBroker broker) If the framework is using an object pool in conjunction with the database, we need to support transactional access to that object pool.
protected void	setThread(java.lang.Thread t)
protected boolean	tryAgain(int errorCode) There may be error codes that mean the connection should simply try the statement a second time.
void	updateExecSql(SQLAssembler sqlObj) Issue an update statement.
protected void	updateStatement(java.sql.PreparedStatement stmt) Usually a no op.

Methods inherited from class java.lang.Object

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

Field Detail

sqlStatementCount

public static int sqlStatementCount

Description of the Field

verbProp

protected static final java.lang.String verbProp

See Also:

Constant Field Values

insrtProp

protected static final java.lang.String insrtProp

See Also:

Constant Field Values

metricsProp

protected static final java.lang.String metricsProp

See Also:

Constant Field Values

verbose

protected static boolean verbose

doInsert

protected static boolean doInsert

manageTransaction

protected static boolean manageTransaction

If manageTransaction is false, no commit or rollback calls will ever be made.

metrics

protected static boolean metrics

connectionSource

protected SqlConnectionFactory connectionSource

userName

protected java.lang.String userName

password

protected java.lang.String password

connectUrl

protected java.lang.String connectUrl

connection

protected java.sql.Connection connection

inTransaction

protected boolean inTransaction

supportsTransaction

protected boolean supportsTransaction

needsExplicitBegin

protected boolean needsExplicitBegin

thread

protected java.lang.Thread thread

pool

protected RDBConnectionPool pool

poolBroker

protected ObjectPoolBroker poolBroker

objArrays

protected final java.lang.Object[] objArrays

lastResultSet

protected GrinderResultSet lastResultSet

cachedStatements

protected SqlStatementCacheItem[] cachedStatements

cachedCount

protected int cachedCount

cachedUpdateStmt

protected java.sql.Statement cachedUpdateStmt

Method Detail

setConnectionSource

public void setConnectionSource(SqlConnectionFactory factory)

Allow brokers to change the connection factory.

Parameters:

factory - The new ConnectionSource value

setObjectPoolBroker

public void setObjectPoolBroker(ObjectPoolBroker broker)

If the framework is using an object pool in conjunction with the database, we need to support transactional access to that object pool.

Parameters:

broker - The new ObjectPoolBroker value

setBrokerProperty

public void setBrokerProperty(BrokerPropertyIF b)

The ability to support properties other than System.getProperties();

Parameters:

b - BrokerPropertyIF The source from which to determine broker properties.

setThread

protected void setThread(java.lang.Thread t)

Parameters:

t - java.lang.Thread

setConnection

protected void setConnection(java.sql.Connection newValue)

Change the connection to the new value.

Parameters:

newValue - The new Connection value

getObjectPoolBroker

public ObjectPoolBroker getObjectPoolBroker()

Every connection may end up manipulating the ObjectPool. Since this needs to be done in a transactional manner, the actual access to the pool is done through the ObjectPoolBroker.

Returns:

com.objectwave.persist.ObjectPoolBroker The associated object pool broker.

getDatabaseMetaData

public java.sql.DatabaseMetaData getDatabaseMetaData()
                                              throws java.sql.SQLException

Returns:

java.sql.DatabaseMetaData

Throws:

java.sql.SQLException - Description of Exception

getThread

public java.lang.Thread getThread()

Get the thread that is currently related to this connection.

Returns:

Thread Null if there is not related thread.

getLastResultSet

public GrinderResultSet getLastResultSet()

Gets the LastResultSet attribute of the RDBConnection object

Returns:

The LastResultSet value

isInTransaction

public boolean isInTransaction()

Returns:

The InTransaction value

getDefaultConnectionSource

protected SqlConnectionFactory getDefaultConnectionSource()

Returns:

The DefaultConnectionSource value

getObjectArrays

protected java.lang.Object[] getObjectArrays()

Returns:

java.lang.Object[]

getPool

protected RDBConnectionPool getPool()

The associated connection pool of which this connection is a member.

Returns:

com.objectwave.persist.RDBConnectionPool

beginTransaction

public void beginTransaction()
                      throws java.sql.SQLException

If the database supports transactions this method would begin the transaction.

Throws:

java.sql.SQLException - Description of Exception

commit

public void commit()
            throws java.sql.SQLException

Issues a database Commit.

Throws:

java.sql.SQLException - Description of Exception

execSql

public void execSql(java.lang.String aString)
             throws java.sql.SQLException

Execute and finish. Dangerous. Don't use. Exposed for bad reasons.

Parameters:

aString - Description of Parameter

Throws:

java.sql.SQLException - Description of Exception

executeQuery

public java.util.List executeQuery(java.lang.String aString,
                                   int numberOfColumns)
                            throws java.sql.SQLException

Execute and finish. Dangerous. Don't use. Exposed for bad reasons.

Parameters:

aString - Description of Parameter

numberOfColumns -

Returns:

Throws:

java.sql.SQLException - Description of Exception

rollback

public void rollback()
              throws java.sql.SQLException

Issues a database rollback.

Throws:

java.sql.SQLException - Description of Exception

freeConnection

public void freeConnection()

Every connection is associated with a particular thread. This drops the relationship between the connection and the thread. Once the pool has been notified that the connection is free, this connection is free to be used by an additional thread.

See Also:

com.objectwave.persist.RDBConnectionPool

alterVendorConnection

public void alterVendorConnection(java.sql.Connection con)
                           throws java.sql.SQLException

Callback hook from connectionSource to allow vendor specific modification to the connection object.

Parameters:

con -

Throws:

java.sql.SQLException

initialize

public void initialize(RDBConnectionPool pool,
                       java.lang.String connectUrl,
                       java.lang.String userName,
                       java.lang.String password)

Parameters:

pool -

connectUrl -

userName -

password -

clearConnection

protected void clearConnection()

Only in the event of a very bad thing should this method be invoked. This will attempt to clean up the database connection related attributes of this object.

addStatement

protected void addStatement(SQLModifier modifier,
                            java.lang.Class persistenceClass,
                            java.sql.PreparedStatement stmt)

Add a prepared statement to this connection's path.

Parameters:

modifier - com.objectwave.persist.SQLModifier

stmt - java.sql.PreparedStatement

persistenceClass - The feature to be added to the Statement attribute

finalize

protected void finalize()
                 throws java.sql.SQLException

Disconnect from database if not already done.

Overrides:

finalize in class java.lang.Object

Throws:

java.sql.SQLException - Description of Exception

findExecSql

public GrinderResultSet findExecSql(SQLAssembler sqlObj)
                             throws java.sql.SQLException,
                                    QueryException

Used for executing any sql query statement.

Parameters:

sqlObj - Description of Parameter

Returns:

Description of the Returned Value

Throws:

java.sql.SQLException - Description of Exception

QueryException - Description of Exception

findExecSql

public GrinderResultSet findExecSql(SQLAssembler sqlObj,
                                    boolean release)
                             throws java.sql.SQLException,
                                    QueryException

Used for executing any sql query statement.

Parameters:

sqlObj - Description of Parameter

release - Description of Parameter

Returns:

Description of the Returned Value

Throws:

java.sql.SQLException - Description of Exception

QueryException - Description of Exception

preparedUpdateSql

public void preparedUpdateSql(SQLModifier sqlObj,
                              Persistence pObj)
                       throws java.sql.SQLException,
                              QueryException

Execute java.sql.PreparedStatement code, perhaps creating the PreparedStatement object in the process.

Parameters:

sqlObj - Description of Parameter

pObj - Description of Parameter

Throws:

java.sql.SQLException - Description of Exception

QueryException - Description of Exception

updateExecSql

public void updateExecSql(SQLAssembler sqlObj)
                   throws QueryException,
                          java.sql.SQLException

Issue an update statement.

Parameters:

sqlObj - Description of Parameter

Throws:

QueryException - Description of Exception

java.sql.SQLException - Description of Exception

tryAgain

protected boolean tryAgain(int errorCode)

There may be error codes that mean the connection should simply try the statement a second time.

Parameters:

errorCode - Description of Parameter

Returns:

true if the sql statement should be tried a second time.

updateStatement

protected void updateStatement(java.sql.PreparedStatement stmt)

Usually a no op. This is a hook point for extending connections.

Parameters:

stmt - java.sql.PreparedStatement

nextPrimaryKey

public int nextPrimaryKey(SQLSelect sqlA)
                   throws java.sql.SQLException,
                          QueryException

Parameters:

sqlA - Description of Parameter

Returns:

Description of the Returned Value

Throws:

java.sql.SQLException - Description of Exception

QueryException - Description of Exception

checkConnection

protected java.sql.Connection checkConnection()
                                       throws java.sql.SQLException

Verify that there is already a connection to the relational database. If not, establish one. There should only be 1 thread per connection.

Returns:

Throws:

java.sql.SQLException - Description of Exception