Should I exclude Spring Framework jars that are not required?

Question

I am developing a simple web application, using Spring Framework. When I add Spring framework to my class path, I see that it has lot of jars which I never use (for example: spring-aop-3.2.3.RELEASE.jar).

Is it a good idea to keep the entire framework intact or remove unused jars?

Answer 1

If you need to remove unused jars, the best way is to use some dependency management tool like Ivy or Maven, and let the tool decide what the required dependencies are. Otherwise it will not be apparent what is really unused or not until you break something.

For instance, if you are using declarative transactions, then removing the AOP jar will cause breakage, because AOP is used to implement that functionality.

If you would rather not use dependency management, it's better to leave everything intact.

There are some cases where you do want to remove/exclude jars. Replacing commons-logging with slf4j is one example. Another example is excluding the log4j dependencies that get dragged in on account of some appender that's packaged with log4j but that you know you will never use. Dependency management tools allow you to tell them what needs to be excluded.

Doing without dependency management management and removing things because you never use them directly is too dangerous.