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[sal2row]

Hey there, I'd need to find out, still not been able to, if it's possibile to prevent a class to use an annotation with a given value of one of its attributes. for instance, to enforce a rule which prevents the value EAGER like

fetch = FetchType.EAGER

to be used in the annotation javax.persistence.OneToMany

thanks in advance, s2r

[codecholeric]

Sure it's possible. The fluent API has at the moment no predefined way to express this, but there are a couple of different ways, to customize this, depending on what you want to emphasize. For example, if you want to express, that fields should not be annotated with @OneToMany(fetch = EAGER), you could do it the following way:

import static com.tngtech.archunit.lang.syntax.ArchRuleDefinition.no;

@ArchTest
public static final ArchRule entitiesShouldntFetchEager =
        no(fields()).should(beAnnotatedWithOneToManyFetchingEager());

private static ClassesTransformer<JavaField> fields() {
    return new AbstractClassesTransformer<JavaField>("fields") {
        @Override
        public Iterable<JavaField> doTransform(JavaClasses collection) {
            Set<JavaField> result = new HashSet<>();
            for (JavaClass javaClass : collection) {
                result.addAll(javaClass.getFields());
            }
            return result;
        }
    };
}

private static ArchCondition<JavaField> beAnnotatedWithOneToManyFetchingEager() {
    return new ArchCondition<JavaField>("be annotated with @OneToMany(fetch = EAGER)") {
        @Override
        public void check(JavaField field, ConditionEvents events) {
            Optional<OneToMany> oneToMany = field.tryGetAnnotationOfType(OneToMany.class);
            boolean satisfied = oneToMany.isPresent() && oneToMany.get().fetch() == FetchType.EAGER;
            String message = String.format("Field %s.%s is%s annotated with @OneToMany(fetch = EAGER)",
                    field.getOwner().getName(), field.getName(), satisfied ? "" : " not");
            events.add(new SimpleConditionEvent(field, satisfied, message));
        }
    };
}

I plan to extend the fluent API in the future, so you get support like noFields().that()..., but at the moment you need the customized code (you could also write something like noClasses().should(customConditionToCheckFields)) Does this help you?

[codecholeric]

Were you able to solve your problem? If yes, I could close this issue :wink:

[sal2row]

Yes mate, sorry for the gap, I've been off work and catching up afterwards. your example worked it out nice and smooth, you may close the issue and thanks a lot for the prompt reply!

[codecholeric]

No problem, happy that your problem was solved, I'll see, that at least the fields() ClassesTransformer of the example will be part of the provided fluent API with the next version :smiley: (the full fluent API for fields, methods, constructors is probably out of scope for me, at the moment)