Re: Keeping Actions clean - separating actions from business mode l from persistence
Mahesh Joshi wrote: I have always wondered where is the best place to do connection management with the dataStore. Should the business Logic do connectionManagement (e.g. opening a connection (via a connection pool or otherwise)) or should that be the responsibility of the persistence layer. Doing it in the latter(PersistenceLayer) frees up the BusinessLayer of connection Mgt code. If you are implementing connectionpool, the overhead is the time to return the connection to the pool and get it back. The iBATIS DAO splits the difference and makes transaction management part of the logical DAO API. So you can specify different connection mechanisms at instantiation, and the implementating code does not need to know the details. The DAO implementation can just call high-level methods like startTransaction, commitTransaction, or rollbackTrnasction. This strategy limits what the implementaton needs to know about the connection management, but still lets the business logic determine what constitutes a transaction (which is often a business decision). -Ted. -- Ted Husted, Junit in Action - http://www.manning.com/massol/, Struts in Action - http://husted.com/struts/book.html, JSP Site Design - http://www.amazon.com/exec/obidos/ISBN=1861005512. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Keeping Actions clean - separating actions from business mode l from persistence
Would it be possible or at least usefull if the SQL objects in that example be used for the Form Beans and for the forms (using XForms). That would really cut don't the amount of work to a minimum Mike |-+ | | Ted Husted | | | [EMAIL PROTECTED]| | | g | | || | | 11/10/2003 11:13 | | | AM | | | Please respond to| | | Struts Users| | | Mailing List| |-+ --| | | | To: Struts Users Mailing List [EMAIL PROTECTED] | | cc: | | Subject: Re: Keeping Actions clean - separating actions from business mode l from persistence | --| Mahesh Joshi wrote: I have always wondered where is the best place to do connection management with the dataStore. Should the business Logic do connectionManagement (e.g. opening a connection (via a connection pool or otherwise)) or should that be the responsibility of the persistence layer. Doing it in the latter(PersistenceLayer) frees up the BusinessLayer of connection Mgt code. If you are implementing connectionpool, the overhead is the time to return the connection to the pool and get it back. The iBATIS DAO splits the difference and makes transaction management part of the logical DAO API. So you can specify different connection mechanisms at instantiation, and the implementating code does not need to know the details. The DAO implementation can just call high-level methods like startTransaction, commitTransaction, or rollbackTrnasction. This strategy limits what the implementaton needs to know about the connection management, but still lets the business logic determine what constitutes a transaction (which is often a business decision). -Ted. -- Ted Husted, Junit in Action - http://www.manning.com/massol/, Struts in Action - http://husted.com/struts/book.html, JSP Site Design - http://www.amazon.com/exec/obidos/ISBN=1861005512. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] The information in this message is confidential and may be legally privileged. It is intended solely for the addressee; access to this email by anyone else is unauthorised. If you are not the intended recipient: (1) you are kindly requested to return a copy of this message to the sender indicating that you have received it in error, and to destroy the received copy; and (2) any disclosure or distribution of this message, as well as any action taken or omitted to be taken in reliance on its content, is prohibited and may be unlawful. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Keeping Actions clean - separating actions from business mode l from persistence
Allow maybe have a couple of generic actions that can save/retrieve and list these objects instead of having to write a action for each form. ie : instead of have to write a form bean/jsp page/edit action/search action/delete action etc.. you just create the xml sql object with some extra details like the search field/edit fields etc. and in you pageflows link the object to the correct type of action like edit/add/search and as these are standard action you do not need to code them? Mike |-+ | | Ted Husted | | | [EMAIL PROTECTED]| | | g | | || | | 11/10/2003 11:13 | | | AM | | | Please respond to| | | Struts Users| | | Mailing List| |-+ --| | | | To: Struts Users Mailing List [EMAIL PROTECTED] | | cc: | | Subject: Re: Keeping Actions clean - separating actions from business mode l from persistence | --| Mahesh Joshi wrote: I have always wondered where is the best place to do connection management with the dataStore. Should the business Logic do connectionManagement (e.g. opening a connection (via a connection pool or otherwise)) or should that be the responsibility of the persistence layer. Doing it in the latter(PersistenceLayer) frees up the BusinessLayer of connection Mgt code. If you are implementing connectionpool, the overhead is the time to return the connection to the pool and get it back. The iBATIS DAO splits the difference and makes transaction management part of the logical DAO API. So you can specify different connection mechanisms at instantiation, and the implementating code does not need to know the details. The DAO implementation can just call high-level methods like startTransaction, commitTransaction, or rollbackTrnasction. This strategy limits what the implementaton needs to know about the connection management, but still lets the business logic determine what constitutes a transaction (which is often a business decision). -Ted. -- Ted Husted, Junit in Action - http://www.manning.com/massol/, Struts in Action - http://husted.com/struts/book.html, JSP Site Design - http://www.amazon.com/exec/obidos/ISBN=1861005512. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] The information in this message is confidential and may be legally privileged. It is intended solely for the addressee; access to this email by anyone else is unauthorised. If you are not the intended recipient: (1) you are kindly requested to return a copy of this message to the sender indicating that you have received it in error, and to destroy the received copy; and (2) any disclosure or distribution of this message, as well as any action taken or omitted to be taken in reliance on its content, is prohibited and may be unlawful. - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Keeping Actions clean - separating actions from business mode l from persistence
Hi
I have generally have done the following:
In the Action:
Use a DTO(data transfer object) to transform the ActionForm
to a business layer data object
Instantiate the business logic class of interest
Call a method on the business logic passing the DTO object
Depending on the status returned, do the appropriate actionForward
call in the action.
The action is a client of the business logic.
(in case I am not using Struts, but vanilla Servlets, the Servlet
replaces the action. the rest till applies).
In the Business logic Layer:
Apply the necessary business rules.
In case of Database persistence, call the persistence manager.
ask the persistence manager to persist the data.
The business logic shouldn't care how the data is persisted.
The standard persistence methods (create, save,
findByPrimaryKey,remove,findBy...)
are exposed to the Business Logic.
The BusinessLogic passes to the Persistence layer objects in the
businessdomain (e.g. standard data objects).
Primary Keys are encapsulated in a PK class.
In the persistence layer
store to the datastore by the method of choice (JDBC/any other
engine etc.)
do the necessary transformation on business data as required by the
persistence store.
do the reverse when retrieving data from the persistence store.
The persistence manager contains the actual classes that know how to
store and retrieve data to the persistent store.
I have always wondered where is the best place to do connection management
with the dataStore.
Should the business Logic do connectionManagement (e.g. opening a connection
(via a connection pool or otherwise)) or should that be the responsibility
of the persistence layer. Doing it in the latter(PersistenceLayer) frees up
the BusinessLayer of connection Mgt code.
If you are implementing connectionpool, the overhead is the time to return
the connection to the pool and get it back.
Thoughts are welcome!
Mahesh
--
Mahesh Joshi
W- 408-543-7214
M- 408-829-8051
[EMAIL PROTECTED]
-Original Message-
From: Sasha Borodin [mailto:[EMAIL PROTECTED]
Sent: Friday, October 10, 2003 5:33 PM
To: Struts Users Mailing List
Subject: Re: Keeping Actions clean - separating actions from business
model from persistence
Matt, thanks for your quick feedback.
I use my own framework because I don't know any better.
public abstract class DaoManager {
public abstract IRecordDao createDao(Connection conn,
String daoClassName)
throws DaoException;
Which tier calls your DaoManager? It seems from your code
that the caller
of DaoManager is responsible to knowing the database configuration
information, as well as the implementing DAO class. Is it the Action?
In other words, who orchestrates the interaction of business and dao
classes? Does the action instantiate a business class and
populate it from
your ActionForm, then get a dao instance from a factory, and
pass it the
business class? Or is there another pattern to this?
Thanks.
Matt
-Sasha
- Original Message -
From: Sasha Borodin [EMAIL PROTECTED]
To: Struts Users Mailing List [EMAIL PROTECTED]
Sent: Friday, October 10, 2003 6:44 PM
Subject: Keeping Actions clean - separating actions from
business modelfrom
persistence
Ted, Matt, Joe, and all the other helpful folks that
chimed in earlier on
persistence mechanisms:
In trying to keep with best practices, I've managed to
remove all model
related code (business logic, and persistence) out of the Actions'
execute()
method. Now I'd like to take it one step further and decouple the
business
model classes from the implementing persistence technology
(btw, settled
on
OJB for now :). From Joe's post, it seems like the DAO
pattern is called
for to accomplish this.
My (slightly off topic) question is this: who develops
their own DAO
framework (like the dao and dao factory interfaces), and
who uses a 3rd
party framework (like iBATIS's Database Layer) and why? There was
something
mentioned about the discovery of the persistence mechanism
as well...
Any references to webpages/books would be appreciated.
BTW, I've been shamelessly posting to this list questions that are
probably
better directed elsewhere. What would be a more appropriate list?
Thank you,
-Sasha
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