net.sf.xbus.technical.database
Class DBConnection

java.lang.Object
  net.sf.xbus.technical.database.DBConnection

All Implemented Interfaces:

TAResource

public class DBConnection
extends java.lang.Object
implements TAResource

DBConnection manages connections to databases.

It implements two Design-Patterns:

1. Singleton: An instance of DBConnection is created for every thread. This instance can be fetched with getInstance().
2. Facade: The complexity of creating and managing a connection is capsuled.

Field Summary

static java.lang.String

UNNAMED

Method Summary

void	bind(java.lang.Object name, int pos, int value) Binds an integer value to a parameter in a stored prepared statement.
void	bind(java.lang.Object name, int pos, java.lang.String value) Binds a string value to a parameter in a stored prepared statement.
void	bindNull(java.lang.Object name, int pos, int type) Binds a null value to a parameter in a stored prepared statement.
static void	clear()
void	close() Closes a resource.
void	commit() Commits all actions on the database.
java.sql.ResultSet	executeRead(java.lang.String statement) Executes a SQL statement to read data.
java.sql.ResultSet	executeReadPrepared(java.lang.Object name) Executes a stored prepared statement.
int	executeUpdate(java.lang.String statement) Executes an update, insert or delete statement.
int	executeUpdatePrepared(java.lang.Object name) Executes a stored prepared statement.
boolean	existsPrepared(java.lang.Object name) Tests if a prepared statement is stored.
static DBConnection	getInstance(java.lang.String name) Delivers an instance of DBConnection.
java.lang.String	getUrl() Returns the complete URL of the DBConnection
void	open() Opens the connection to the database.
void	prepareStatement(java.lang.Object name, java.lang.String statement) Stores the given SQL statement as a prepared statement under the given name.
void	reopen() Reopens a database connection after an error has been detected.
void	rollback() Performs a rollback for all actions on the database.

Methods inherited from class java.lang.Object

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

Field Detail

UNNAMED

public static final java.lang.String UNNAMED

See Also:

Constant Field Values

Method Detail

getInstance

public static DBConnection getInstance(java.lang.String name)
                                throws XException

Delivers an instance of DBConnection.

If it is the first call for the actual thread, a new DBConnection -object gets created. Subsequent calls in this thread will deliver the object, that has been created by the first call.

Throws:

XException

open

public void open()
          throws XException

Opens the connection to the database.

Specified by:

open in interface TAResource

Throws:

XException - if something goes wrong

close

public void close()
           throws XException

Description copied from interface: TAResource

Closes a resource.

Specified by:

close in interface TAResource

Throws:

XException - if something goes wrong

commit

public void commit()
            throws XException

Commits all actions on the database.

Specified by:

commit in interface TAResource

Throws:

XException - if something goes wrong

rollback

public void rollback()
              throws XException

Performs a rollback for all actions on the database.

Specified by:

rollback in interface TAResource

Throws:

XException - if something goes wrong

reopen

public void reopen()
            throws XException

Reopens a database connection after an error has been detected. All internal variables are initialized.

Throws:

XException

executeRead

public java.sql.ResultSet executeRead(java.lang.String statement)
                               throws XException

Executes a SQL statement to read data.

Parameters:

statement - SQL statement to read data

Returns:

set of read rows

Throws:

XException - if something goes wrong

executeUpdate

public int executeUpdate(java.lang.String statement)
                  throws XException

Executes an update, insert or delete statement.

Parameters:

statement - SQL statement to update, insert or delete rows

Returns:

number of rows affected

Throws:

XException - if something goes wrong

prepareStatement

public void prepareStatement(java.lang.Object name,
                             java.lang.String statement)
                      throws XException

Stores the given SQL statement as a prepared statement under the given name.

Throws:

XException

bind

public void bind(java.lang.Object name,
                 int pos,
                 java.lang.String value)
          throws XException

Binds a string value to a parameter in a stored prepared statement.

Parameters:

name - the name under which the prepared statement is stored

pos - position of the parameter in the prepared statement

value - value that will be bound to the parameter

Throws:

XException

bind

public void bind(java.lang.Object name,
                 int pos,
                 int value)
          throws XException

Binds an integer value to a parameter in a stored prepared statement.

Parameters:

name - the name under which the prepared statement is stored

pos - position of the parameter in the prepared statement

value - value that will be bound to the parameter

Throws:

XException

bindNull

public void bindNull(java.lang.Object name,
                     int pos,
                     int type)
              throws XException

Binds a null value to a parameter in a stored prepared statement.

Parameters:

name - the name under which the prepared statement is stored

pos - position of the parameter in the prepared statement

type - the type of the column (see java.sql.Types)

Throws:

XException

executeUpdatePrepared

public int executeUpdatePrepared(java.lang.Object name)
                          throws XException

Executes a stored prepared statement.

Parameters:

name - the name under which the prepared statement is stored

Returns:

number of affected rows

Throws:

XException

executeReadPrepared

public java.sql.ResultSet executeReadPrepared(java.lang.Object name)
                                       throws XException

Executes a stored prepared statement.

Parameters:

name - the name under which the prepared statement is stored

Returns:

the ResultSet for the query

Throws:

XException

existsPrepared

public boolean existsPrepared(java.lang.Object name)

Tests if a prepared statement is stored.

Parameters:

name - the name under which the prepared statement is stored

Returns:

true if the prepared statement exists

clear

public static void clear()

getUrl

public java.lang.String getUrl()

Returns the complete URL of the DBConnection