Logging a methods's name and parameters

Question

I've been working with a company that, in this current project, has to implement a policy of writing lots of trace logging in code (JAVA) that has already been completed for some time.

I am trying to avoid changing every single method just to write a logger.log('desired values') like code line on all of them. it's just too counter-productive.

Is there a generic way to log a method name, the parameters that it received, without changing much of the code? I've been researching annotations and stuff like that but there are a lot of methods with different parameters so i haven't been able to come up with a good solution.

EDIT 1: The project is being developed on eclipse. I'm doing some changes in a portal using Liferay and JBoss.

EDIT 2: I've followed a solution given to me here and used interceptors. The only change i had to do to the existing methods was to add an annotation to them, which was quite acceptable. For more info search in this link: http://docs.oracle.com/javaee/6/tutorial/doc/gkeed.html

Answer 1

The best way is to use AOP and Java annotations. I would recommend to use @Loggable annotation and an AspectJ aspect from jcabi-aspects (I'm a developer):

@Loggable(Loggable.DEBUG)
public String load(URL url) {
  return url.openConnection().getContent();
}

Answer 2

Go to Window->Preferences, select Java->Editor->Templates, create a new template named "logmeth" with Pattern i.e.:

if(logger.isDebug())logger.debug("${exception_variable_name} ${return_type} "+getClass().getName()+"${enclosing_method}(${enclosing_method_arguments})"+String.format("***",${enclosing_method_arguments}));

and press OK.

In java Editor write logmeth and press Strg+space+space and Enter and Eclipse will write i.e.:

if(logger.isDebug())logger.debug("e boolean hasFuture(man, woman)"
            + String.format("***", man, woman));

Eclipse is so cool.

Answer 3

You should take a look at AOP. It enables you to inject code at runtime and thus add logging before/after each method.

Answer 4

You can use interceptors http://docs.oracle.com/javaee/6/tutorial/doc/gkeed.html to intercept calls to public methods without any code changes, it is impossible to use this technique with non-public methods though.