CODEWITHSUNDEEP
javalombok
hatellla
hatellla

Reputation: 5132

Can't access constructor with @AllArgsConstructor but works with @RequiredArgsConstructor

I have a POJO class as follows:

@Value
@Builder
public class XYZ {

    @NonNull
    private final String a;

    @NonNull
    private final String b;

    @NonNull
    private final State state;

    public enum State {
        STARTED
    }
}

When I try to create the object of XYZ class from my tst/ folder, it fails with an error that constructor cannot be accessed from outside package but when I used @RequiredArgsConstructor in that POJO, then it starts working fine and doesn't show the error. The actual error is this:

error: XYZ(String,String,State) is not public in XYZ; cannot be accessed from outside package

So, I was wondering what is the difference between @AllArgsConstructor(provided by @Value) and @RequiredArgsConstructor because of which I am seeing this issue.

Upvotes: 0

Views: 2204

Answers (1)

Jan Rieke
Jan Rieke

Reputation: 8102

When processing its annotations, Lombok does not consider the order of those annotations in the source file. Instead, each annotation type has a priority that determines the processing order. This is because there are dependencies between different annotation types.

@Builder has a higher priority than @Value. So Lombok first generates the package-private all-args constructor required for the builder. As a result, there is already a constructor present when processing @Value. According to the @Value documentation, "any explicit constructor, no matter the arguments list, implies lombok will not generate a constructor".

However, in my opinion this is a bit misleading in the documentation. The constructor generated for @Builder is more something like an implementation detail, but I would not call it an "explicit constructor". (By "explicit" the authors probably mean "not a default constructor".)

Once you add @RequiredArgsConstructor or @AllArgsConstructor (which is the same in this case), the constructor becomes public, and neither @Builder nor @Value has to generate it any more.

Upvotes: 4

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