Enforcing Naming Convention with aspects

Question

I just started AspectJ in university and in one of the labs we have a question where we need to enforce a naming convention across all classes which states that all variables must not include any numbers, i.e. if I create a variable called test1 it should give out a warning. I would appreciate if you guys could point me in the right direction.

Answer 1

The maximum what I can suggest about this is the following:

public aspect NamingConventionsAspect {
    pointcut methodWith0() : execution(* *.*0*(..));
    pointcut methodWith1() : execution(* *.*1*(..));
    pointcut methodWith2() : execution(* *.*2*(..));
    pointcut methodWith3() : execution(* *.*3*(..));
    pointcut methodWith4() : execution(* *.*4*(..));
    pointcut methodWith5() : execution(* *.*5*(..));
    pointcut methodWith6() : execution(* *.*6*(..));
    pointcut methodWith7() : execution(* *.*7*(..));
    pointcut methodWith8() : execution(* *.*8*(..));
    pointcut methodWith9() : execution(* *.*9*(..));
    pointcut readFieldWith0() : get(* *.*0*);
    pointcut readFieldWith1() : get(* *.*1*);
    pointcut readFieldWith2() : get(* *.*2*);
    pointcut readFieldWith3() : get(* *.*3*);
    pointcut readFieldWith4() : get(* *.*4*);
    pointcut readFieldWith5() : get(* *.*5*);
    pointcut readFieldWith6() : get(* *.*6*);
    pointcut readFieldWith7() : get(* *.*7*);
    pointcut readFieldWith8() : get(* *.*8*);
    pointcut readFieldWith9() : get(* *.*9*);
    pointcut setFieldWith0() : set(* *.*0*);
    pointcut setFieldWith1() : set(* *.*1*);
    pointcut setFieldWith2() : set(* *.*2*);
    pointcut setFieldWith3() : set(* *.*3*);
    pointcut setFieldWith4() : set(* *.*4*);
    pointcut setFieldWith5() : set(* *.*5*);
    pointcut setFieldWith6() : set(* *.*6*);
    pointcut setFieldWith7() : set(* *.*7*);
    pointcut setFieldWith8() : set(* *.*8*);
    pointcut setFieldWith9() : set(* *.*9*);
    pointcut classWith0() : within(*0*);
    pointcut classWith1() : within(*1*);
    pointcut classWith2() : within(*2*);
    pointcut classWith3() : within(*3*);
    pointcut classWith4() : within(*4*);
    pointcut classWith5() : within(*5*);
    pointcut classWith6() : within(*6*);
    pointcut classWith7() : within(*7*);
    pointcut classWith8() : within(*8*);
    pointcut classWith9() : within(*9*);

    declare error : methodWith0() || methodWith1() || methodWith2() || methodWith3() || methodWith4() || 
    methodWith5() || methodWith6() || methodWith7() || methodWith8() || methodWith9() || readFieldWith0() || 
    readFieldWith1() || readFieldWith2() || readFieldWith3() || readFieldWith4() || readFieldWith5() || 
    readFieldWith6() || readFieldWith7() || readFieldWith8() || readFieldWith9() || setFieldWith0() || 
    setFieldWith1() || setFieldWith2() || setFieldWith3() || setFieldWith4() || setFieldWith5() || setFieldWith6() || 
    setFieldWith7() || setFieldWith8() || setFieldWith9() || classWith0() || classWith1() || classWith2() || 
    classWith3() || classWith4() || classWith5() || classWith6() || classWith7() || classWith8() || classWith9() : 
        "Identifiers shouldn't contain numbers!";
}

Answer 2

I'm pretty sure that's impossible.

AspectJ does not have access to local variables at all, and fields are only available through the get() and set() pointcuts, so you can only declare an error or warning if such a field is accessed, not if it is just defined without access.

I'd go with a dedicated Source metric tool like PMD instead. It's easy to write a custom rule, and PMD has wide support in build systems and IDEs.

Aspects are really about behaviour, not about naming.

Update: OK, if you can live with the restrictions, here's an aspect that matches all access to fields with a number in their name:

public aspect TestAspect {

    pointcut accessBadField() :
        get(* *.*1*) ||
        get(* *.*2*) ||
        get(* *.*3*) ||
        get(* *.*4*) || 
        get(* *.*5*) ||
        get(* *.*6*) ||
        get(* *.*7*) ||
        get(* *.*8*) ||
        get(* *.*9*) ||
        get(* *.*0*)
        ;

    declare warning : accessBadField() : 
        "Please don't use numbers in field names";

}

Reference:

• Pointcut semantics