org.brains2b.data
Interface DataController

public interface DataController

Interface for a general Controller to use for all different data objects.

Implementation of this class should be able to find the DataControl implementation for the type of Object which is provided as paramters through the methods

Implementations would look something like:

 		public int update(Object o) throws Exception {
 			return findDc(Object o).updateOnPk();
 		}
 
 		public DataControl findDc(Object o) throws Exception {
 			//some method to find and instantiate the DataControl
 		}

This interface is defined in general terms because no assumptions should be made about the type of datastore so the DataControl must be as general as possible. The most simple implementation would be using a JDBC connection, but you could also use it for XML or flat file datastorage TODO provide reference to working example.

Version:

0.10 [19-6-2002]

Author:

dennis@brains2b.nl

See Also:

DataControl

Method Summary

int	delete(java.lang.Object o) delete an object of type o from the datastore
int	insert(java.lang.Object o) insert an object of type o to the datastore
java.lang.Object	select(java.lang.Object o, java.lang.Object condition) select an Object of the type of the Object o which match the supplied condition.
java.util.Vector	selectFromCondition(java.lang.Object o, Condition condition) select a collection of Objects of the type of the Object o which match the supplied condition.
java.util.Vector	selectFromParent(java.lang.Object o, java.lang.Object parent) select a collection of Objects of the type of the Objecto which match a defined relation with the parent.
int	update(java.lang.Object o) update an object of type o to the datastore

Method Detail

update

public int update(java.lang.Object o)
           throws java.lang.Exception

update an object of type o to the datastore

Parameters:

o - Object, the object to update

Returns:

int, the number or records updated, should always return one

Throws:

Exception, - exception thrown from the specific data store controls, such as a JDBC driver

java.lang.Exception

See Also:

DataControl.updateOnPk()

insert

public int insert(java.lang.Object o)
           throws java.lang.Exception

insert an object of type o to the datastore

Parameters:

o - Object, the object to insert

Returns:

int, the number or records inserted, should always return one

Throws:

Exception, - exception thrown from the specific data store controls, such as a JDBC driver

java.lang.Exception

See Also:

DataControl.insert()

delete

public int delete(java.lang.Object o)
           throws java.lang.Exception

delete an object of type o from the datastore

Parameters:

o - Object, the object to delete

Returns:

int, the number or records deleted, should always return one

Throws:

Exception, - exception thrown from the specific data store controls, such as a JDBC driver

java.lang.Exception

See Also:

DataControl.updateOnPk()

select

public java.lang.Object select(java.lang.Object o,
                               java.lang.Object condition)
                        throws java.lang.Exception

select an Object of the type of the Object o which match the supplied condition.

Parameters:

o - Object the object which determines the type of objects you want to retrieve. An implementantion should not assume anything about the content of this Object and most implementations will ignore the values.

condition - Condition the condition which should be met by the retrieved objects

Returns:

An object which meets the condition. If more then one object meets the criteria implementations should only return the first one. Should return null if no object meets the condition.

Throws:

Exception, - exception thrown from the specific data store controls, such as a JDBC driver

java.lang.Exception

See Also:

DataControl.selectFromCondition(Condition), Condition

selectFromParent

public java.util.Vector selectFromParent(java.lang.Object o,
                                         java.lang.Object parent)
                                  throws java.lang.Exception

select a collection of Objects of the type of the Objecto which match a defined relation with the parent.

Parameters:

o - Object the object which determines the type of objects you want to retrieve. An implementantion should not assume anything about the content of this Object and most implementations will ignore the values.

parent - Object, this Object should contain the necessary information to make a relation with this Object

Returns:

A Vector of Objects which has a relation with the parent. Should return null if no relation could be established

Throws:

Exception, - exception thrown from the specific data store controls, such as a JDBC driver

java.lang.Exception

See Also:

DataControl.selectOnParent(Object)

selectFromCondition

public java.util.Vector selectFromCondition(java.lang.Object o,
                                            Condition condition)
                                     throws java.lang.Exception

select a collection of Objects of the type of the Object o which match the supplied condition.

Parameters:

o - Object the object which determines the type of objects you want to retrieve. An implementantion should not assume anything about the content of this Object and most implementations will ignore the values.

condition - Condition the condition which should be met by the retrieved objects

Returns:

A Vector of Objects which meet the condition. Should return null if no object meets the condition.

Throws:

Exception, - exception thrown from the specific data store controls, such as a JDBC driver

java.lang.Exception

See Also:

DataControl.selectFromCondition(Condition), Condition