commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Harish Krishnaswamy <hkrishnasw...@comcast.net>
Subject Re: [HiveMind] Basic questions about Service
Date Thu, 25 Sep 2003 17:13:46 GMT
Well, may be not "real" real, we are just going to develop a basic LIMS 
system prototype for our lab here. Although some of our prototypes have 
taken a life of their own!

-Harish

Christian Essl wrote:

> That's indeed exciting! As far as I see the first real project. I 
> would be realy interested in knowing for what and how you use HiveMind 
> and how you get along with it.
>
> On Thu, 25 Sep 2003 12:51:14 -0400, Harish Krishnaswamy 
> <hkrishnaswamy@comcast.net> wrote:
>
>> Absolutely, I agree it is not yet prime time to go against J2EE 
>> (guess that's why we have the EJBProxyFactory!) and it very well 
>> could, down the road. We are actually starting a new small project 
>> this coming Monday and I may be using HiveMind to try it out for 
>> real! It is exciting!
>>
>> -Harish
>>
>> Christian Essl wrote:
>>
>>> Oh yes that's a good point - now I know even better why I like 
>>> HiveMind :-) - and I totally agree. Seriously I think this should 
>>> get somehow on the front-page of HiveMind. You expressed well this 
>>> free glue aproach.
>>>
>>> What I wanted to say is that for now functionality is missing which 
>>> could make it a real competitor to J2EE. I did not want to say that 
>>> HiveMind is worse than J2EE. Howard did and does a realy good job, 
>>> but nobody can make everything in one day (especially if I come up 
>>> with a new 'big' suggestion every day).
>>>
>>> HiveMind maybe soon there where EJBs are but to get started used now 
>>> and in the next week a field where HiveMind can compete with every 
>>> other technology easaly is the web-tier layer. And I think getting 
>>> started used is the most important thing for further development.
>>>
>>> On Thu, 25 Sep 2003 12:02:57 -0400, Harish Krishnaswamy 
>>> <hkrishnaswamy@comcast.net> wrote:
>>>
>>>> The thing I like about HiveMind is the free form schema, that is 
>>>> awesome. I think that's what allows HiveMind to be really clean and 
>>>> small at the core and yet allows unlimited possibilities unlike 
>>>> other frameworks where if you want a new feature you end up 
>>>> modifying the core. HiveMind does ROCK!
>>>>
>>>> -Harish
>>>>
>>>> Christian Essl wrote:
>>>>
>>>>> Yes I agree with you. I also agree that HiveMind is easier to use 
>>>>> than EJBs. But I also have to say that until HiveMind supports 
>>>>> transactions, messaging, security, persistence etc. and that all 
>>>>> in a possible clustered enviroment there is still quite a way to 
>>>>> go. So I do not currently (and for the near future) see HiveMind 
>>>>> as any form of a replacement of J2EE.
>>>>>
>>>>> I rather see it as something which helps to better structure and 
>>>>> support your 'normal' applications and provides a facade to EJBs. 
>>>>> Ie in the Web tier I imagine Services like caches, validators, 
>>>>> pools, front security checking, access to templates etc. Maybe 
>>>>> also connections pools, hibernate-services etc. for more simple 
>>>>> web-apps.
>>>>>
>>>>> On Thu, 25 Sep 2003 10:17:11 -0400, Howard M. Lewis Ship 
>>>>> <hlship@comcast.net> wrote:
>>>>>
>>>>>> What your are describing is pretty close to J2EE dogma.
>>>>>>
>>>>>> A service facade (stateless session bean) is a business process 
>>>>>> concerning Employee.
>>>>>>
>>>>>> An additonal service, behind the facade, provides persistancy for

>>>>>> Employee objects, i.e., its a Data
>>>>>> Access Object (really, a Data Access Service).
>>>>>>
>>>>>> There's nothing inherently wrong with this model, and much that 
>>>>>> is right.
>>>>>>
>>>>>> I've used other systems, including Apple's Enterprise Objects 
>>>>>> Framework, that merges the Value
>>>>>> object (called an EO, or "Enterprise Object") with its business 
>>>>>> logic. This is attractive, but
>>>>>> doesn't scale well ... it works out to be nice to seperate the 
>>>>>> data aspects (the value object and
>>>>>> the data access service) from the business logic, because 
>>>>>> business logic is much more likely to
>>>>>> change over time ... or even be quite dynamic (for example, 
>>>>>> driven by a flexible workflow engine).
>>>>>> Once you start thinking about externalizing business logic, it 
>>>>>> ends up making sense (to me) to
>>>>>> externalize all of it, for consistency.
>>>>>>
>>>>>> Good, workable, scalable OO is more about aggregation than about

>>>>>> inheritance. Coming out of the
>>>>>> Objective-C/Apple/NeXT world initially, my early work on Tapestry

>>>>>> reflects an overuse of inheritance
>>>>>> over aggregation (even today), a mistake I'm not making with 
>>>>>> HiveMind.
>>>>>>
>>>>>> Where HiveMind rocks over J2EE is that it is much, much, much 
>>>>>> easier to create new services and make
>>>>>> them seemlessly work together.
>>>>>>
>>>>>> -- Howard M. Lewis Ship
>>>>>> Creator, Tapestry: Java Web Components
>>>>>> http://jakarta.apache.org/tapestry
>>>>>> http://jakarta.apache.org/commons/sandbox/hivemind/
>>>>>> http://javatapestry.blogspot.com
>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Harish Krishnaswamy [mailto:hkrishnaswamy@comcast.net]

>>>>>>> Sent: Wednesday, September 24, 2003 9:39 PM
>>>>>>> To: 'Jakarta Commons Developers List'
>>>>>>> Subject: [HiveMind] Basic questions about Service
>>>>>>>
>>>>>>>
>>>>>>> I am a little confused now. I am confused as to what the 
>>>>>>> boundaries of a service are. Is there even a distinction between

>>>>>>> a Service and a domain object? I start seeing people actually

>>>>>>> suck out the behavior of domain objects into services and have

>>>>>>> the domain object as a simple JavaBeans data object. I literally

>>>>>>> saw an example that had an Employee object which represented
the 
>>>>>>> database table and an EmployeeService which represented the 
>>>>>>> behavior for the Employee object. To me this sounds like its

>>>>>>> against the principles of OO (assign the responsibility to the

>>>>>>> information expert). So this leads to a more basic question -

>>>>>>> what is a Service? I think we need a technical definition for

>>>>>>> Service. I thought of the Service as an interface to a subsystem

>>>>>>> / a specific function. Am I missing something?
>>>>>>>
>>>>>>> -Harish
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> ---------------------------------------------------------------------

>>>>>>>
>>>>>>> To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
>>>>>>> For additional commands, e-mail: 
>>>>>>> commons-dev-help@jakarta.apache.org
>>>>>>>
>>>>>>
>>>>>>
>>>>>> ---------------------------------------------------------------------

>>>>>>
>>>>>> To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
>>>>>> For additional commands, e-mail: commons-dev-help@jakarta.apache.org
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> ---------------------------------------------------------------------
>>>> To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
>>>> For additional commands, e-mail: commons-dev-help@jakarta.apache.org
>>>>
>>>
>>>
>>>
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
>> For additional commands, e-mail: commons-dev-help@jakarta.apache.org
>>
>
>
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: commons-dev-help@jakarta.apache.org
>
>


Mime
View raw message