Telling IntelliJ IDEA which methods not to identify as unused

Question

IntelliJ IDEA has a handy feature to detect unused methods and show them in grey, hinting a potential warning for dead code.

Some methods, however, are not executed directly but via reflection. A good example would be @RequestMapping-annotated methods which are executed by Spring. IntelliJ has decent Spring integration hence it detects this annotation and does not mark such a method as unused.

I have a tiny AJAX framework where I use my own annotation to point which method to execute based on certain HTTP request properties (very similar to what @RequestMapping is doing). Understandably, IntelliJ has no idea what does my annotation stand for and and marks such a method as unused, adding unnecessary noise.

I was thinking of:

• annotating my annotation with another annotation, but are there any standard ones that would do the job without any extra effort?
• finding a particular setting in IntelliJ to identify custom annotation for marking methods as used, but this would require other team members to do the same, basically a pain.

Can anyone suggest any ideas how to solve this problem?

Solution 1

You can tell IntelliJ to not to warn about used for any method/field annotated with the annotation the "unused" method has.

It should be a quick fix all you have to do is hit <Alt>+<Enter> and select Suppress for methods annotated by ...

You don't need to add anything to you code and you only have to do this once per annotation.

Solution 2

@SuppressWarnings("unused") should work.

Solution 3

@Peter Lawrey s solution did not help in my version of Intellij (14.1.1).

I used the hard way around:Settings-Editor->Inspections->Unused declarion Now there is an Options point, scroll down to Configure annotations... and you can add your annotation there.

Comments

[mindas]

Thanks for the answer. Ideally I would want my custom annotation to be able to handle this automagically so I don't have to add @SuppressWarnings("unused") on each method. Or are you suggesting I should annotate my annotation (rather than method) itself?

[Vance Maverick]

No, I wasn't suggesting this. I don't know how to "tell IDEA which methods not to identify as unused" except by using the standard annotation. Peter's suggestion is nice, but requires just as many annotaions.

[mindas]

I think Peter's @UsedViaReflection is just a pseudo code, it can be any annotation really. It isn't ideal (as I was mentioning in my question), but I guess there are no other alternatives.

[Zarathustra]

unfortunately I do not have this option, my annotation is @WebMethod and I am using Intellij 14.1.1 . Any idea why I do not have this option available?

[Salim]

This works with recent versions like a charm. IntelliJ really comes with some magic.

[TmTron]

I've accidentally suppressed this for "fields annotated with xx". To undo this operation find <component name="EntryPointsManager"> in the .idea/misc.xml file and adapt it (don't forget to update the list attribute, when you change the count of items)

[Nashev]

Maybe this action is hidden at the "More actions..." link at the bottom right corner in a warning's hint window