New domain !!!

Hi all,

I have changed to the new domain: http://acuriousanimal.orggeo.net. I hope to have some time to move some post to the new site.

Working with tiles

Today I found this very educative posts at Sergey Malenkov's Blog, and I would like to put a reference to them in my blog:

• Triangular tile map


• Square tile map

Design Patterns Explained With Java and Uml2

Design Patterns Explained With Java and Uml2 2008

Publish at Scribd or explore others: Internet & Technolog eBooks java Design Patterns

GTD lightweigh but effective tools

Some time ago I started reading about GTD "philosophy". GTD is easy to follow and effective in your day by day. In my case it helps me a lot at work, improving my organization and the problem resolution. Like other methodologies the difficult isn't in the methodology itself but in ourself, that is, we now what are the "right steps" but forgot to follow them.

Here I point three little tools can help with your day by day (applying GTD):

• MonkeyGTD
• d3
  
• GTDTiddlyWiki

All three are based on the TiddlyWiki (imagine a HTML page that modifies itself). In the case of 'd3' you have an util calendar to put your reminders.

Simply the truth

Here I would like to put a copy of a post read from Navegapolis (Spanish), but contains a link to a video with an speaking of Ken Schwaber.

Si tienes un equipo de ingenieros excelentes, que utilizan excelentes herramientas, trabajan con prácticas de ingeniería correctas, comprenden perfectamente el negocio del cliente, disponen de los recursos que necesitan y no se les interrumpe en su trabajo... Puedes trabajar con scrum: tendrás un incremento de software al final de cada iteración.

De todas formas, scrum también funciona con idiotas. Puedes tener un grupo de idiotas, no hace falta ni que hayan ido a la escuela, ni que sepan de informática o de ingeniería del software. Un grupo que se odien entre ellos, no comprendan el negocio del cliente y trabajen con herramientas traperas... también produciran incrementos periódicos... de mierda.

Está bien, porque sabes lo que tendrás al final de cada iteración.

Amazon WebServices and... sort your params !!!

A couple of weeks ago I start working with Amazon Web Services. Very, very powerful. I just work with a few features like EC2 and S3 but I love it. There are APIs in most language (Java, PHP, ...) to use the Amazon WS.

Anyway, this post is a reminder for all of you that want to implement an API for AWS in some other language (like me and CFML).

Extracted from http://docs.amazonwebservices.com/AWSEC2/2008-08-08/DeveloperGuide/ I copy the sentence that solve my headache:

Sort the query parameters (not URL-encoded) without using case-sensitively.

When you invoke some AWS action the params must be sorted by its name.

Be happy and read the doc.

Heavyweight + Lightweight

Today seems a good day for many Java developer.
Via Rich Unger's Blog I found the problem with havyweight and lightweight components is solved in Java6u12 and also Java6u12 early access is availably too.
I must test it in the Balloon project, nice to merge WWJ with NetBeans platform.

Working with rollbacks in JPA

First examples you could see about JPA shows you how easy is to work with it. Don't misunderstand me, I like JPA, we (the developers) need a standard in the ORM world.
What I mean is when you really start working in a project using JPA discover you must understand fine the standard and the ORM engine implementing it (in my case TopLink).

Previously, in another post I put a couple of links on how to detach entities, here I would like to point to another post, from David Van Couvering's blog, talking about transaction rollbacks.

Databases: thinking different

Today I read another great article from Martin Fowler's web page DatabaseThaw.
In these days it seems there is no place to databases philosophy other than relational and the RDBMS titans.
I would like to note one database in "the dark side" commented in the above article, neo4j, a graph oriented database.

Detach an entity from JPA persistence context

1 - Previously
Ok, you have designed a great domain model and then translete it to a database or, also much probably, have designed a great database and then generated the corresponding entity classes.

2 - Now
You have some GUI to get user input data. Easy. You create a new domain object (customer, product, bill or whatever else) and persist it through your favourite JPA engine.
Now you have some GUI that lists the available objects in your domain (again customer, product, bill or whatever else. I good idea could be obtain that objects in the way of domain object, I suppose for that reason you create a model, then you can change properties in some of that objects and store (persist) again those changes, so called merge changes.

3 - The question
Here comes the question. How can you detach an object from the persistence context? If you could get a dettached object you could modify its properties, then if the user agrees persist its new state or leave unchaged otherwise.

4 - The solution (or better say 'some of the solutions')
Detach an entity from JPA/EJB3 persistence context