Lombok Builder: Build object only if any one field is non null otherwise dont build object

Question

Lombok Builder: Build object only if any one field is non null otherwise don't build object

@Builder
public class InterestLimit{
    String field1;
    String field2;
}

Answer 1

You can annotate a constructor with the @Builder annotation. In there, you can validate the input.

public class InterestLimit {
    String field1;
    String field2;

    @Builder
    public InterestLimit(String f1, String f2) {
        if (f1 == null && f2 == null)
            throw new IllegalArgumentException();
        this.field1 = f1;
        this.field2 = f2;   
    }
}

Please also look into the documentation to fully understand the @Builder annotation:

• https://projectlombok.org/features/Builder
• https://www.baeldung.com/lombok-builder

Another way is to specify the build method, as seen in this post:

• https://trguduru.github.io/2019/06/add-custom-validations-with-lombok-builders/

@AllArgsConstructor
@Builder
public class InterestLimit {
    String field1;
    String field2;

    public static class InterestLimitBuilder {
        public InterestLimit build() {
            if (field1 == null && field2 == null)
                throw new IllegalArgumentException();
            return new InterestLimit(field1, field2);
        }
    }
}