CODEWITHSUNDEEP
javamethods
Jonathan Pitre
Jonathan Pitre

Reputation: 2435

Is it possible to prevent a class from using a method in java?

Suppose I have a class called Foo. This class will be modified by many people, and WILL print information to the console. To this effect, we have the following method:

private void print(String message){ ... }

which prints out to the screen in the format we want.

However, while reviewing code from other devs I see that they constantly call System.out.println(...)
instead, which results in barely-readable printouts.

My question is the following: is it possible to prevent any and every use of System.out.println() in Foo.java? If so, how?

I've tried looking this up, but all I found had to do with inheritance, which is not related to my question.

Thanks a lot!
N.S.

EDIT: I know that whatever I have to do to prevent the use of a method could be removed by a dev, but we have as a policy never to remove code marked //IMPORTANT so it could still be used as a deterrent.

EDIT2: I know I can simply tell the devs not to do it or use code reviews to filter the "errors" out but 1) I'm already doing it and it costs a lot of time and 2) the question is whether this is possible or not, NOT how to deal with my devs.

Upvotes: 2

Views: 644

Answers (6)

csturtz
csturtz

Reputation: 6580

No, it's not possible to 100% prevent a class from ever using a specific method in Java.

Having that said...

My suggestion would be to add code analysis to your build process and failing the build on any occurrence of System.out.println. A good place to start if you're interested in going this route would be to check out PMD.

Also... have some constructive discussions with your developers and talk about why they're doing what they're doing. Good luck.

Upvotes: 1

Laf
Laf

Reputation: 8235

You can replace the OutputStream of System with your own implementation that would either throw an exception, or redirect the call to your own print implementation (which you would need to make public).

Upvotes: 1

Guido
Guido

Reputation: 47705

You can redirect System.out calls to a streams that ignores the output or that redirects it to your logging system.

System.setOut(printStream);

You can also kill those using System.out.println in a production environment.

Upvotes: 2

David
David

Reputation: 322

Although communicating that developers should not use System.out directly would be preferred, you could set System.out to another PrintStream, then use the alternative PrintStream in the private method. That way, when people use System.out.println they won't output anything but you'll still be able to use the alternative PrintStream... something like they do here: http://halyph.blogspot.com/2011/07/how-to-disable-systemout.html

Upvotes: 3

Mike Samuel
Mike Samuel

Reputation: 120586

Pre-commit hooks for your revision control system (SVN, Git, Mercurial) can grep for uses of System.{err,out} and prevent commit if they occur.

http://stuporglue.org/svn-pre-commit-hook-which-can-syntax-check-all-files/ is an example that takes an action for different changed files based on file extension for SVN. You should be able to modify that example to take an example based on some subset of Java files and reject if something like the following is true

egrep -q '\bSystem\.(err|out)\b'

Upvotes: 2

A.H.
A.H.

Reputation: 66323

public methods are just that - public. There is no way to restrict access to them.

This kind of problem is usually "solved" by setting up some code-checker like PMD or checkstyle and integrating them into the continuous integration build. So violations of these stuff will be emailed to someone with a big hammer :-)

Upvotes: 6

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