com.bentofw.dao
Class SimpleDaoHelperImpl

java.lang.Object
  com.bentofw.dao.SimpleDaoHelperImpl

All Implemented Interfaces:

SimpleDaoHelper

Direct Known Subclasses:

DaoHelperForJdbc, DaoHelperForJndi, DaoHelperForPooledStatement

public abstract class SimpleDaoHelperImpl
extends java.lang.Object
implements SimpleDaoHelper

The abstract super class for the implementation of SimpleDaoHelper interface.

The 3 implementations of SimpleDaoHelper interface are available in this package. They are:

• DaoHelperForJndi: Creates PreparedStatement by JNDI DataSource
• DaoHelperForJdbc: Creates PreparedStatement by JDBC Connection
• DaoHelperForPooledStatement: Creates PreparedStatement by OOP PooledStatement

And all of these implementations are the sub-class of this abstract class. In usual, you need not be concerned with this class.

Author:

Jun Inamori

Constructor Summary

SimpleDaoHelperImpl()

Method Summary

abstract void	closeResource(java.sql.ResultSet res, java.sql.PreparedStatement ps, java.sql.Connection con, boolean isOK) Close the specified ResultSet, PreparedStatement and Connection.
abstract java.sql.Connection	getConnection() Return the JDBC Connection.
abstract java.sql.PreparedStatement	getPrepareStatement(java.sql.Connection con, java.lang.String sql) Return the JDBC PreparedStatement for the given SQL statement.
java.util.List	select(QueryData data, int[] return_types) Based on the given QueryData object, this method executes PreparedStatement.
int	update(QueryData data) Based on the given QueryData object, this method executes PreparedStatement.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleDaoHelperImpl

public SimpleDaoHelperImpl()

Method Detail

getConnection

public abstract java.sql.Connection getConnection()
                                           throws java.sql.SQLException

Return the JDBC Connection. How to get the Connection depends on the implementation.

In case that you use DaoHelperForJndi, this method queries Connection on the JNDI DataSource. If you use DaoHelperForJdbc, Connection is created from DriverManager each time this method is called. Or, when DaoHelperForPooledStatement is used, this method returns null, because OOP PooledStatement keeps the Connection in its pool along with the PreparedStatement.

Specified by:

getConnection in interface SimpleDaoHelper

Returns:

Connection

Throws:

java.sql.SQLException

getPrepareStatement

public abstract java.sql.PreparedStatement getPrepareStatement(java.sql.Connection con,
                                                               java.lang.String sql)
                                                        throws java.sql.SQLException

Return the JDBC PreparedStatement for the given SQL statement.

In case that you use DaoHelperForJndi or DaoHelperForJdbc, this method creates PreparedStatement from the specified Connection.

If you use DaoHelperForPooledStatement, this method picks the PreparedStatement from the pool of OOP PooledStatement. Because Connection is always null, please specify null as the first parameter.

Specified by:

getPrepareStatement in interface SimpleDaoHelper

Parameters:

con - JDBC Connection

sql - SQL statement

Returns:

PreparedStatement

Throws:

java.sql.SQLException

closeResource

public abstract void closeResource(java.sql.ResultSet res,
                                   java.sql.PreparedStatement ps,
                                   java.sql.Connection con,
                                   boolean isOK)

Close the specified ResultSet, PreparedStatement and Connection.

In case that you use DaoHelperForJndi or DaoHelperForJdbc, this method calls close method on them.

If you use DaoHelperForPooledStatement, this method closes only ResultSet. And PreparedStatement will be pushed back to the pool of OOP PooledStatement. As for Connection, this method does nothing, because it is always null.

Specified by:

closeResource in interface SimpleDaoHelper

Parameters:

res - ResultSet

ps - PreparedStatement

con - Connection

isOK - This parameter will be used only by DaoHelperForPooledStatement, because the PreparedStatement should not be pushed back to the pool if something is wrong. But, to make your code portable between the implementations, please specify the correct value. If SQLException is thrown while playing with PreparedStatement, please specify false. Otherwise, true.

select

public java.util.List select(QueryData data,
                             int[] return_types)
                      throws java.sql.SQLException,
                             SimpleException

Based on the given QueryData object, this method executes PreparedStatement.

Specified by:

select in interface SimpleDaoHelper

Parameters:

data - QueryData object.

return_types - The int array which consists of the pre-defined int constants.

Returns:

List object which includes List objects, each of which represents the selected row.

Throws:

java.sql.SQLException

SimpleException

update

public int update(QueryData data)
           throws java.sql.SQLException,
                  SimpleException

Based on the given QueryData object, this method executes PreparedStatement.

Specified by:

update in interface SimpleDaoHelper

Parameters:

data - QueryData object.

Returns:

int value returned from PreparedStatement.

Throws:

java.sql.SQLException

SimpleException