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JSpecify: Propagate nullability annotations to mapper implementation #4076
Description
Use case
While trying the latest beta I've noticed that IDE adds a Overriding method parameters are not annotated warning to all null marked mappers because the generated implementations don't include any annotation at all:
Generated Code
For example, here:
@Mapper
@NullMarked // or @NullMarked in package-info.java
public interface NullMarkedMapper {
@Mapping(target = "foo", source = "source1.foo")
@Mapping(target = "bar", source = "source1.bar")
@Mapping(target = "baz", source = "source2.baz")
Target map(Source1 source1, @Nullable Source2 source2);
}Generated code could be:
@Generated(
value = "org.mapstruct.ap.MappingProcessor",
date = "0000-00-00T00:00:00+0000",
comments = "version: , compiler: javac, environment: Java 21"
)
@NullMarked
public class NullMarkedMapperImpl implements NullMarkedMapper {
@Override
public Target map(Source1 source1, @Nullable Source2 source2) {
Long baz = null;
if ( source2 != null ) {
baz = source2.getBaz();
}
String foo = null;
foo = source1.getFoo();
boolean bar = false;
bar = source1.isBar();
Target target = new Target( foo, bar, baz );
return target;
}
}Possible workarounds
Right now I'm ignoring the warning because it's not a compilation issue
MapStruct Version
1.7.0.Beta2
Activity
RaniAgus commentedon Jun 28, 2026
Oops, might be related to #4036
filiphr commentedon Jun 28, 2026
Thanks for the feedback @RaniAgus. It's extremely valuable. This is indeed similar with #4036. However, that one is for the helper methods that we generate. I'll keep both and try to look for a potential solution to pass the annotations. My goal is to have no warnings from the tools, to truly be native to the use of JSpecify
pkernevez commentedon Aug 4, 2026
As a temporary solution you can add
@AnnotateWith(NullMarked.class)to your mapper.pkernevez commentedon Aug 4, 2026
In my case the parameter never have annotations.
So the generated code is:
Instead of you sample:
Is there a reason to not replicate all the parameters annotations ? (included non JSpecify ones)
mapstruct#4076 Propagate JSpecify nullability annotations to the mapp…