com.webobjects.jdbcadaptor
Class JDBCContext

java.lang.Object
  |
  +--com.webobjects.eoaccess.EOAdaptorContext
        |
        +--com.webobjects.jdbcadaptor.JDBCContext

public class JDBCContext

extends EOAdaptorContext

Nested Class Summary

Nested classes inherited from class com.webobjects.eoaccess.EOAdaptorContext

EOAdaptorContext.Delegate

Field Summary

static String	ANSI92ConformanceKey
static String	ANSIEntryConformance
static String	ANSIFullConformance
static String	ANSIIntermediateConformance
static String	CreateParamsKey
static String	DBMSNameKey
static String	DefaultJDBCTypeKey
static String	DriverNameKey
static String	DriverVersionKey
static String	IdentifierQuoteStringKey
static String	InternalTypeKey
static String	MaxScaleKey
static String	MinScaleKey
static String	NonNullableColumnsKey
static String	NullableKey
static String	PrecisionKey
static String	SearchableKey
static String	StringFunctionsKey

Fields inherited from class com.webobjects.eoaccess.EOAdaptorContext

AdaptorContextBeginTransactionNotification, AdaptorContextCommitTransactionNotification, AdaptorContextRollbackTransactionNotification

Constructor Summary

JDBCContext(EOAdaptor adaptor)

Method Summary

void	beginTransaction() An abstract method that should be implemented by subclasses to attempt to begin a new transaction.
void	commitTransaction() An abstract method that should be implemented by subclasses to attempt to commit the last transaction begun.
boolean	connect()
Connection	connection()
EOAdaptorChannel	createAdaptorChannel() An abstract method that should be implemented by subclasses to create and return a new EOAdaptorChannel, or null if a new channel cannot be created.
void	disconnect()
void	handleDroppedConnection() An abstract method that should be implemented by subclasses to clean up after the receiver's adaptor has lost its connection to its database server.
void	rollbackTransaction() An abstract method that should be implemented by subclasses to attempt to roll back the last transaction begun.

Methods inherited from class com.webobjects.eoaccess.EOAdaptorContext

adaptor, canNestTransactions, channels, defaultDelegate, delegate, hasBusyChannels, hasOpenChannels, hasOpenTransaction, setDefaultDelegate, setDelegate, transactionDidBegin, transactionDidCommit, transactionDidRollback, transactionNestingLevel

Methods inherited from class java.lang.Object

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

Field Detail

ANSI92ConformanceKey

public static final String ANSI92ConformanceKey

ANSIEntryConformance

public static final String ANSIEntryConformance

ANSIFullConformance

public static final String ANSIFullConformance

ANSIIntermediateConformance

public static final String ANSIIntermediateConformance

CreateParamsKey

public static final String CreateParamsKey

DBMSNameKey

public static final String DBMSNameKey

DefaultJDBCTypeKey

public static final String DefaultJDBCTypeKey

DriverNameKey

public static final String DriverNameKey

DriverVersionKey

public static final String DriverVersionKey

IdentifierQuoteStringKey

public static final String IdentifierQuoteStringKey

InternalTypeKey

public static final String InternalTypeKey

MaxScaleKey

public static final String MaxScaleKey

MinScaleKey

public static final String MinScaleKey

NonNullableColumnsKey

public static final String NonNullableColumnsKey

NullableKey

public static final String NullableKey

PrecisionKey

public static final String PrecisionKey

SearchableKey

public static final String SearchableKey

StringFunctionsKey

public static final String StringFunctionsKey

Constructor Detail

JDBCContext

public JDBCContext(EOAdaptor adaptor)

Method Detail

beginTransaction

public void beginTransaction()

Description copied from class: EOAdaptorContext

An abstract method that should be implemented by subclasses to attempt to begin a new transaction. A successful invocation of beginTransaction must be paired with an invocation of either commitTransaction or rollbackTransaction to end the transaction.

The Enterprise Objects Framework automatically wraps database operations in transactions, so you don't have to begin and end transactions explicitly. In fact, letting the framework manage transactions is sometimes more efficient. You typically implement beginTransaction only to execute more than one database operation in the same transaction scope.

This method should invoke the delegate method adaptorContextShouldBegin before beginning the transaction. If the transaction is begun successfully, the method should invoke transactionDidBegin on the receiver and invoke the delegate method adaptorContextDidBegin. Should throw a runtime exception if the attempt is unsuccessful. Some possible reasons for failure are:

• A connection to the database hasn't been established.
• A transaction is already in progress.
• A fetch is in progress.
• The delegate refuses.
• The database server fails to begin a transaction.

Specified by:

beginTransaction in class EOAdaptorContext

See Also:

EOAdaptorContext.hasOpenTransaction(), EOAdaptorContext.transactionDidBegin(), EOAdaptorContext.Delegate.adaptorContextShouldBegin(EOAdaptorContext adaptorContext), EOAdaptorContext.Delegate.adaptorContextDidBegin(EOAdaptorContext adaptorContext)

commitTransaction

public void commitTransaction()

Description copied from class: EOAdaptorContext

An abstract method that should be implemented by subclasses to attempt to commit the last transaction begun. Should invoke the delegate method adaptorContextShouldCommit before committing the transaction. If the transaction is committed successfully, the method should invoke transactionDidCommit and invoke the delegate method adaptorContextDidCommit. Should throw a runtime exception if the attempt is unsuccessful. Some possible reasons for failure are:

• A transaction is not in progress.
• Fetches are in progress.
• The delegate refuses.
• The database server fails to commit.

Specified by:

commitTransaction in class EOAdaptorContext

See Also:

EOAdaptorContext.beginTransaction(), EOAdaptorContext.rollbackTransaction(), EOAdaptorContext.hasBusyChannels(), EOAdaptorContext.transactionDidCommit(), EOAdaptorContext.Delegate.adaptorContextShouldCommit(EOAdaptorContext adaptorContext), EOAdaptorContext.Delegate.adaptorContextDidCommit(EOAdaptorContext adaptorContext)

connect

public boolean connect()
                throws JDBCAdaptorException

JDBCAdaptorException

connection

public Connection connection()

createAdaptorChannel

public EOAdaptorChannel createAdaptorChannel()

Description copied from class: EOAdaptorContext

An abstract method that should be implemented by subclasses to create and return a new EOAdaptorChannel, or null if a new channel cannot be created. Should set the new channel's adaptorContext to this.

A newly created adaptor context has no channels. Specific adaptors have different limits on the maximum number of channels a context can have, and createAdaptorChannel should fail if a creating a new channel would exceed the limits.

Specified by:

createAdaptorChannel in class EOAdaptorContext

Returns:

A new EOAdaptorChannel.

See Also:

EOAdaptorChannel.adaptorContext(), EOAdaptorContext.channels()

disconnect

public void disconnect()
                throws JDBCAdaptorException

JDBCAdaptorException

handleDroppedConnection

public void handleDroppedConnection()

Description copied from class: EOAdaptorContext

An abstract method that should be implemented by subclasses to clean up after the receiver's adaptor has lost its connection to its database server. Invoked from EOAdaptor's handleDroppedConnection, this method should clean up the state of the receiver and its adaptor channels so they can be safely disposed of without any errors. Subclasses must implement this method if the adaptor supports automatic database reconnection.

Never invoke this method yourself; it is invoked automatically by the Enterprise Objects Framework.

Specified by:

handleDroppedConnection in class EOAdaptorContext

See Also:

EOAdaptor.handleDroppedConnection()

rollbackTransaction

public void rollbackTransaction()

Description copied from class: EOAdaptorContext

An abstract method that should be implemented by subclasses to attempt to roll back the last transaction begun. Should invoke the delegate method adaptorContextShouldRollback before rolling back the transaction. If the transaction is begun successfully, the method should invoke transactionDidRollback and invoke the delegate method adaptorContextDidRollback. Should throw a runtime exception if the attempt is unsuccessful. Some possible reasons for failure are:

• A transaction is not in progress.
• Fetches are in progress.
• The delegate refuses.
• The database server fails to rollback.

Specified by:

rollbackTransaction in class EOAdaptorContext

See Also:

EOAdaptorContext.beginTransaction(), EOAdaptorContext.commitTransaction(), EOAdaptorContext.transactionDidRollback(), EOAdaptorContext.Delegate.adaptorContextShouldRollback(EOAdaptorContext adaptorContext), EOAdaptorContext.Delegate.adaptorContextDidRollback(EOAdaptorContext adaptorContext)