Commons-Beanutils Is Slow

The BeanUtil.popupate(bean,map) can be very handy, but if you care about performance, it is quite slow. I ran a micro benchmark on my machine (centrino 1.8ghz, JDK1.5) and found out that BeanUtils is up to 40x slower than a hand coded solution (where I assign each bean field manually). I was a bit surprised to find such a difference. I suppose there is a big penalty for using reflection and another big one for the BeanUtils abstraction (automatic casting, etc.). I did another test without BeanUtils, using if/else statements vs HashMap.get and found out that the if/else string.equals(...) statements can degrade performance by about 10x. The HashMap appears to be very performant, even with just a few elements in.

In conclusion, if you need more performance, consider hand coding or code generation (using aspectj, or annotations for example) rather than BeanUtils. Actually nowadays, using annotations where you used beanutils probably makes much more sense .

Commons-Beanutils Is Slow

The BeanUtil.popupate(bean,map) can be very handy, but if you care about performance, it is quite slow. I ran a micro benchmark on my machine (centrino 1.8ghz, JDK1.5) and found out that BeanUtils is up to 40x slower than a hand coded solution (where I assign each bean field manually). I was a bit surprised to find such a difference. I suppose there is a big penalty for using reflection and another big one for the BeanUtils abstraction (automatic casting, etc.). I did another test without BeanUtils, using if/else statements vs HashMap.get and found out that the if/else string.equals(...) statements can degrade performance by about 10x. The HashMap appears to be very performant, even with just a few elements in.

In conclusion, if you need more performance, consider hand coding or code generation (using aspectj, or annotations for example) rather than BeanUtils. Actually nowadays, using annotations where you used beanutils probably makes much more sense .

Generate your RSS feed in Java

There are some open source projects that can help you in generating or reading RSS feeds in Java. I found only two libraries a bit mature, other code is often embedded in other open source products (jroller for example):

• Informa: Does various RSS formats and Atom 0.3. Documentation is better than its alternative, but less focused (has some hibernate helper thingy, some lucene helper, etc.).
  
• Sandler: There is no working homepage while I am writing this. But the code is of decent quality, supports Atom 0.3 and RSS 1.0. It is easy to use it. However in reality it is not much more than a wrapper around some XML parser specialized in generating an RSS structure or an Atom structure.
• Ooops, I forgot another important one, Rome. This RSS/Atom framework with a catchy name is very similar to Informa, has good documentation and good looking code. Under the hood it makes use of jdom.

I personally use dom4j since I only need to generate RSS, and RSS, or Atom are just XML. I don't find it particularly verbose to use dom4j for that, and it is very flexible.

If you need to parse feeds, then those libraries might make sense and save you a bit of time. For generating, I think their main interest is to abstract you from the differences in formats. So if you need to handle different formats, a framework will allow you to do it through only one API, which can be a big time-saver.

Categories: java, rss, atom