uk.ac.ed.epcc.webapp.jdbc

Interface DatabaseService

All Superinterfaces:

AppContextCleanup, AppContextService<DatabaseService>, CloseRegistry, Contexed

All Known Implementing Classes:

DefaultDataBaseService, JNDIDatabaseService, WrappedDatabaseService

public interface DatabaseService
extends Contexed, AppContextService<DatabaseService>, CloseRegistry

A service that supplies the DataBase Connection

Field Summary

Fields

Modifier and Type	Field and Description
static Feature	LOG_INSERT_FEATURE
static Feature	LOG_QUERY_FEATURE
static Feature	LOG_UPDATE
static Feature	USE_SQL_DISTICT_FEATURE

Method Summary

Modifier and Type	Method and Description
void	commitTransaction() flush changes since start of last commit.
java.util.Map<java.lang.String,java.lang.Object>	getConnectionAttributes() get a map of information about the connection
SQLContext	getSQLContext() get SQLContext using the default ConfigService
SQLContext	getSQLContext(java.lang.String tag) get alternative database SQLContext If the tag is null it returns the same SQLContext as getSQLContext().
SQLContext	getSQLContext(java.lang.String tag, java.util.Properties config_props) get a {SQLContext} based on properties
void	handleError(java.lang.String message, java.sql.SQLException e) Handle an unexpected database exception.
boolean	inTransaction() Are we already in a transaction
void	logError(java.lang.String message, java.sql.SQLException e) handle an SQLException directly.
void	rollbackTransaction() Abort changes since start or last commit
void	startTransaction() Start a database transaction Transactions cannot be nested so use inTransaction() if possible doubt.
void	stopTransaction() finish transaction (includes commit).
int	transactionStage() returns the number of times commitTransaction() has been called since the last transaction start.

Methods inherited from interface uk.ac.ed.epcc.webapp.Contexed

getContext

Methods inherited from interface uk.ac.ed.epcc.webapp.AppContextService

getType

Methods inherited from interface uk.ac.ed.epcc.webapp.AppContextCleanup

cleanup

Methods inherited from interface uk.ac.ed.epcc.webapp.jdbc.CloseRegistry

addClosable, closeRetainedClosables, removeClosable

Field Detail

LOG_QUERY_FEATURE

static final Feature LOG_QUERY_FEATURE

USE_SQL_DISTICT_FEATURE

static final Feature USE_SQL_DISTICT_FEATURE

LOG_INSERT_FEATURE

static final Feature LOG_INSERT_FEATURE

LOG_UPDATE

static final Feature LOG_UPDATE

Method Detail

getSQLContext

SQLContext getSQLContext(java.lang.String tag,
                         java.util.Properties config_props)
                  throws java.sql.SQLException

get a {SQLContext} based on properties

Parameters:

tag -

config_props -

Returns:

SQLContext

Throws:

java.sql.SQLException

getSQLContext

SQLContext getSQLContext()
                  throws java.sql.SQLException

get SQLContext using the default ConfigService

Returns:

SQLContext to database

Throws:

java.sql.SQLException

getSQLContext

SQLContext getSQLContext(java.lang.String tag)
                  throws java.sql.SQLException

get alternative database SQLContext If the tag is null it returns the same SQLContext as getSQLContext().

Parameters:

tag -

Returns:

Connection to database

Throws:

java.sql.SQLException

inTransaction

boolean inTransaction()

Are we already in a transaction

Returns:

boolean

transactionStage

int transactionStage()

returns the number of times commitTransaction() has been called since the last transaction start. If this returns 0 then a roll-back will return to the state at startTransaction() if greater than zero there have been intermediate commits. To aid in testing the value is not reset to zero until the next call to startTransaction()

Returns:

int

startTransaction

void startTransaction()

Start a database transaction Transactions cannot be nested so use inTransaction() if possible doubt.

rollbackTransaction

void rollbackTransaction()

Abort changes since start or last commit

commitTransaction

void commitTransaction()

flush changes since start of last commit. Unlike the commit method of a Connection this is a NOP if not in a transaction. Call before an operation that modifies external state as these won't roll-back. However probably better to defer the external state change using the CleanupService unless the transaction phases all make sense in their own right.

stopTransaction

void stopTransaction()

finish transaction (includes commit).

handleError

void handleError(java.lang.String message,
                 java.sql.SQLException e)
          throws DataFault

Handle an unexpected database exception. Most of the time this will just re-throw the exception wrapped in a DataFault however this also allow special handing of certain classes of error such as SQLTransientExceptions

Parameters:

e -

Throws:

DataException

DataFault

logError

void logError(java.lang.String message,
              java.sql.SQLException e)

handle an SQLException directly. Normally this will just log the error however this also allow special handing of certain classes of error such as SQLTransientExceptions

Parameters:

message -

e -

getConnectionAttributes

java.util.Map<java.lang.String,java.lang.Object> getConnectionAttributes()
                                                                  throws java.lang.Exception

get a map of information about the connection

Returns:

Throws:

java.lang.Exception