Session Handling in JATO

Stevens,

Thanks a lot for your reply.This has helped me a lot in understanding and

implementing the Session handling.One thing I struggled to fix was adding

the UserData.class in ModelTypeMapImpl.java

I am starting to admire JATO and I look forward to explore more into this.

Here comes my further questions on JATO....

Assume I have created a UserData (extending SessionModel) with two

parameters userId and passWord.

I want to write a method getDetails(),setDetails() which will fetch

details, update details from/to database respectively.

How do I go about this?Sample Code ..

Most of the business logic in ND5.0 is commented out in JATO (migrated

code).The commented code is appearing in the ViewBeans.

Enlighten me on the approach to rewrite the business logic. We basically

have little Functional Knowledge of the application written in ND5.0 -

Bearing this in mind, what is the cost-effective way to migrate the

business logic in JATO

Thanks,

Gajendran.

"Matthew Stevens"

Subject: RE: [iPlanet-JATO]

Session Handling

08/08/01 09:10 PM in JATO

Please respond to

iPlanet-JATO

Gajendran,

Which app server are you using when you have null reference returned for

HttpSession? This should not happen because the JATO base implementation

class for the Module Servlet (ApplicationServletBase) will automatically

force the creation of HttpSession in the container; this is required to

support the Session events.

Just to be clear (refer to the Java Docs for JATO) the API for accessing

the

HttpSession is

HttpSession sess = <RequestContext>.getRequest().getSession();

sess.setAttribute("XXXX",o);

. . .

There are rules defined in the latest Regular Expression Tool rules which

map NetD User Session APIs to HttpSession APIs. You can essential rely on

this. There are rules which is most cases assist you fixing the CSpValue

aspects of User Session expressions as well.

I highly recommend that you assemble your common Session attributes (NetDyn

User Session Objects) and encapsulate them in a java.model.SessionModel.

This model implements the <Model>.getValue() and <Model>.setValue() using

retrieval and storage from HttpSession automatically. In other words,

SessionModel is a proxy to HttpSession via a JATO Model API.

For a clean implementation, you can derive a specialized SessionModel. For

instance, it is fairly common to store a number of Login or User related

attributes in session. You can create a class UserData which derives from

SessionModel, add your own purposeful accessors (setters and getters), and

reap the benefits of having this session data available via Model APIs.

Here is an example below

public class UserData extends SessionModel

{

. . .

protected static final String LOGIN_TIME

= "USERDATA_LOGIN_TIME";

public void initializeLoginTime()

{

setValue(LOGIN_TIME, new Long((new Date()).getTime())

}

public long getLoginTime()

{

TypeConverter.asLong(getValue(LOGIN_TIME));

}

public long getLoginTimeAsString()

{

TypeConverter.asString(new

Date(TypeConverter.asLong(getValue(LOGIN_TIME))));

}

}

UserData x =

(UserData)<RequestContext>.getModelManager().getModel(UserData.class);

x.initializeLoginTime();

With respect to business objects, the JATO Models are in fact intended for

this purpose (e.g. Business Delegate pattern). JATO Models can

automatically be stored in the HttpSession via the ModelManager support for

retrieving and storing Models in session (see the getModel() APIs). If a

Model is backed by a database (e.g. QueryModel or UIFFunctionModel) then

you

need to decide whether the data is too expensive to be pulled out of the

backing store on each request. There is a tradeoff (especially in data

integrity) on whether Models should be cached in the session in addition

its

primary storage in the database. Here is an example. For one NetDynamics

customer which had a PAC based Function Data Object which accessed consumer

Credit Reports from a mainframe, the cost in both RPC latency and local CPU

time for post-processing the results was far greater than the cost of

storing the 1-2K of credit report data in the HttpSession. For this

customer, it was very simple to leverage the ModelManager automatic feature

for storing and retrieving (serializable) Models from HttpSession.

public Model getModel(java.lang.Class modelClass,

java.lang.String instanceName,

boolean lookInSession,

boolean storeInSession)

Model credit_report =

getModel(ConsumerCreditReportModel.class,some_name,true,true);

In this way, the first access to getModel returned an empty/default

implementation class for the ConsumerCreditReportModel. Execution of this

getModel() call on subsequent requests retrieved the Model out of

HttpSession.

let us know if this answers your question,

matt

> --Original Message--

> From: <a href="/group/SunONE-JATO/post?protectID=123166177056078154218098066036192063041 102166009043241114211116056004136218164200193244096076095219">gajendran.gopin athan@i...</a>

> Sent: Wednesday, August 08, 2001 7:42 AM

> Subject: [iPlanet-JATO] Session Handling in JATO

>

>

> I am converting an application in ND5.0 to J2EE.

> I have started working on this very recently.

> I am looking for elaborate explanations on certain gray areas

>

> My immediate concern using the JATO classes is "How do I store

information

> in the session"

> The getRequestContext,getSession methods in ViewBean is returning null

>

> Would appreciate if you could share your thoughts on "how to proceed"

with

> session management (Storing/Retrieving objects in session).

>

> I am not clear on the Model classes.I plan to customize the model

> class per

> the application needs and store it in the session...

> For example, say there are 5 fields in the JSP

> (Textbox1,Textbox2,Textbox3,Textbox4,Textbox5)

>

> How about having 5 String attributes in the Model Class with Business

> methods to Insert/Update the database

>

> Would really appreciate more responses in this regard

>

> Thanks,

> Gajendran

<a href="/group/SunONE-JATO/post?protectID=210083235237078198050118178206047166215 146166214017110250006230056039126077176105140127082088124241215002153">iPlane t-JATO-unsubscribe@egroups.com</a>

Guest at 2007-7-1 18:23:27 >

Gajendran--

> Here comes my further questions on JATO....

> Assume I have created a UserData (extending SessionModel) with two

> parameters userId and passWord.

> I want to write a method getDetails(),setDetails() which will fetch

> details, update details from/to database respectively.

> How do I go about this?Sample Code ..

As I mentioned in my previous email, there are standard approaches in JATO

for this. But first, let me clarify something.

You have an object called UserData whose data you want to store in session.

You shouldn't derive this object from JATO's SessionModel class, because

SessionModel is merely an adaptation of the JATO Model interface to the J2EE

HttpSession interface. Instead, you should derive UserData from

DefaultModel. (You may want to change the name of your object to

"UserDataModel" to be consistent with JATO's naming convention.)

DefaultModel is a serializable class, so this means that you can simply

store the UserData object directly in the session as needed. There are also

methods in the ModelManager class that will help you store and retrieve a

Model from session.

Now, because this class implements the Model interface, you can bind it to

JATO display fields. Also, because the UserData class ISA Model, you can

have it implement one or more of the ExecutingModel interfaces, like

RetrievingModel and UpdatingModel. These interfaces give you standard

methods for the behavior you want to put in your getDetails()/setDetails()

method. Once you have these standard methods, you can then integrate the

UserData class with JATO WebActions, and have it automatically execute

during specific actions.

Finally, for an example of implementing a custom Model class, see the

BasicCustomModel.java and BasicCustomModelImpl.java classes in the JATO 1.1

sample application, available here:

<a href="ftp://ftp1.netscape.com/private/jato/1_1/JatoSample.war">ftp://ftp1.ne tscape.com/private/jato/1_1/JatoSample.war</a>

Todd

Guest at 2007-7-1 18:23:27 >