构建企业级应用的六大误区(英文)
Six Common Enterprise Programming Mistakes
by Brett McLaughlin, author of Building Java Enterprise Applications Vol. I: Architecture
04/03/2002
Instead of giving you tips to use in your programming (at least directly), I want to look at some common mistakes made in enterprise programming. And instead of focusing on what to do, I want to look at what you should not do.
Most programmers take books like mine and add in the good things, but they leave their mistakes in the very same programs! So I´ll toUCh on several common errors I see in enterprise programming, and then briefly mention how to avoid those mistakes.
1. It doesn´t matter what data store type you use.
One of the first steps in designing an application is to decide on the data store. It used to be that every application was based upon a database, and this was simply not an issue. However, there has recently been an upsurge in additional options: you can now use relational databases, XML databases, object databases, Directory servers, and more.
As a result, many companies have begun to interchange these different data stores, often without any real thought. If a directory server is cheaper than a database, it is used to replace the database. XML databases are put in place because they are "sexy" and satisfy "technology lust." However, the trend to use any data store for any case is simply absurd; your performance will began to degrade, your code will become overly complex, and you´ll have no idea why.
Each data store has a specific purpose. For example, directory servers are optimized for frequent reads, with few writes. Authentication and searching for names and addresses is a perfect usage of a directory server. However, if you start to add data programmatically to a directory server often, you'll see a degradation in performance. A database is better in this case.
The same sort of choices are important when determining what kind of database to use. For example, using an XML database in an application that never pulls XML directly out of that database is silly. You´re choosing a technology (XML), and then never using that technology.
In my new book, I detail these exact choices. (Yes, it´s more than just a book about Java.) In fact, you´ll learn how to integrate databases and directory servers into the same application, and even how to transfer data back and forth between them.
