org.dbmaintain.database.impl
Class DefaultSQLHandler

java.lang.Object
  org.dbmaintain.database.impl.DefaultSQLHandler

All Implemented Interfaces:

SQLHandler

public class DefaultSQLHandler
extends Object
implements SQLHandler

Class to which database updates and queries are passed. Is in fact a utility class, but is a concrete instance to enable decorating it or switching it with another implementation, allowing things like a dry run, creating a script file or logging updates to a log file or database table.

Author:

Filip Neven, Tim Ducheyne

Constructor Summary

DefaultSQLHandler()
Constructs a new instance that connects to the given DataSource

DefaultSQLHandler(boolean doExecuteUpdates)
Constructs a new instance that connects to the given DataSource

Method Summary

void	closeAllConnections() Closes all connections that were created and cached by this SQLHandler.
void	endTransactionAndCommit(DataSource dataSource) Ends a transaction that was started using startTransaction by committing and turning auto commit back on.
void	endTransactionAndRollback(DataSource dataSource) Ends a transaction that was started using startTransaction by rolling back and turning auto commit back on.
void	execute(String sql, DataSource dataSource) Executes the given statement.
int	executeUpdateAndCommit(String sql, DataSource dataSource) Executes the given statement and commits the changes to the database
boolean	exists(String sql, DataSource dataSource) Returns true if the query returned a record.
protected Connection	getConnection(DataSource dataSource) Returns a Connection to the given DataSource.
long	getItemAsLong(String sql, DataSource dataSource) Returns the long extracted from the result of the given query.
String	getItemAsString(String sql, DataSource dataSource) Returns the value extracted from the result of the given query.
Set<String>	getItemsAsStringSet(String sql, DataSource dataSource) Returns the items extracted from the result of the given query.
void	startTransaction(DataSource dataSource) Starts a transaction by turning of auto commit.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultSQLHandler

public DefaultSQLHandler()

Constructs a new instance that connects to the given DataSource

DefaultSQLHandler

public DefaultSQLHandler(boolean doExecuteUpdates)

Constructs a new instance that connects to the given DataSource

Parameters:

doExecuteUpdates - Boolean indicating whether updates should effectively be executed on the underlying database

Method Detail

execute

public void execute(String sql,
                    DataSource dataSource)

Description copied from interface: SQLHandler

Executes the given statement.

Specified by:

execute in interface SQLHandler

Parameters:

sql - The sql string for retrieving the items

dataSource - The dataSource, not null

executeUpdateAndCommit

public int executeUpdateAndCommit(String sql,
                                  DataSource dataSource)

Description copied from interface: SQLHandler

Executes the given statement and commits the changes to the database

Specified by:

executeUpdateAndCommit in interface SQLHandler

Parameters:

sql - The sql string for retrieving the items

dataSource - The dataSource, not null

Returns:

The nr of updates

getItemAsLong

public long getItemAsLong(String sql,
                          DataSource dataSource)

Description copied from interface: SQLHandler

Returns the long extracted from the result of the given query. If no value is found, a DbMaintainException is thrown.

Specified by:

getItemAsLong in interface SQLHandler

Parameters:

sql - The sql string for retrieving the items

dataSource - The dataSource, not null

Returns:

The long item value

getItemAsString

public String getItemAsString(String sql,
                              DataSource dataSource)

Description copied from interface: SQLHandler

Returns the value extracted from the result of the given query. If no value is found, a DbMaintainException is thrown.

Specified by:

getItemAsString in interface SQLHandler

Parameters:

sql - The sql string for retrieving the items

dataSource - The dataSource, not null

Returns:

The string item value

getItemsAsStringSet

public Set<String> getItemsAsStringSet(String sql,
                                       DataSource dataSource)

Description copied from interface: SQLHandler

Returns the items extracted from the result of the given query.

Specified by:

getItemsAsStringSet in interface SQLHandler

Parameters:

sql - The sql string for retrieving the items

dataSource - The dataSource, not null

Returns:

The items, not null

exists

public boolean exists(String sql,
                      DataSource dataSource)

Description copied from interface: SQLHandler

Returns true if the query returned a record.

Specified by:

exists in interface SQLHandler

Parameters:

sql - The sql string for checking the existence

dataSource - The dataSource, not null

Returns:

True if a record was returned

startTransaction

public void startTransaction(DataSource dataSource)

Starts a transaction by turning of auto commit. Make sure to call endTransaction at the end of the transaction

Specified by:

startTransaction in interface SQLHandler

Parameters:

dataSource - The data source, not null

endTransactionAndCommit

public void endTransactionAndCommit(DataSource dataSource)

Ends a transaction that was started using startTransaction by committing and turning auto commit back on.

Specified by:

endTransactionAndCommit in interface SQLHandler

Parameters:

dataSource - The data source, not null

endTransactionAndRollback

public void endTransactionAndRollback(DataSource dataSource)

Ends a transaction that was started using startTransaction by rolling back and turning auto commit back on.

Specified by:

endTransactionAndRollback in interface SQLHandler

Parameters:

dataSource - The data source, not null

closeAllConnections

public void closeAllConnections()

Closes all connections that were created and cached by this SQLHandler. This method must always be invoked before disposing this object.

Specified by:

closeAllConnections in interface SQLHandler

getConnection

protected Connection getConnection(DataSource dataSource)

Returns a Connection to the given DataSource. The first time a Connection is requested, a new one is created using the given DataSource. All subsequent calls with the same DataSource as parameter will return the same Connection instance.

Parameters:

dataSource - provides access to the database

Returns:

a Connection to the database for the given DataSource.