强制mapstruct不调用has *方法

Question

I wrote a mapstruct mapper that uses a mapping like this:

@Mapping(target = "userId", source = "id.userId")

When I looked at the autogenerated mapstruct class I stubled upon that code:

if ( !foobar.hasId() ) {
    return null;
}

This is a problem for me as hasId() does not what mapstruct expects here. Can I force mapstruct somehow to not generate code that uses this method but checks for id != null or something?

I could use a mapping like @Mapping(target = "userId", expression= "java(...)") but I think there should be another way.

Answer 1

Yes you can force MapStruct not to use those presenceCheckers . You can find more information in source presence checking in the documentation.

Basically the only way to do this is to provide an implementation of the MapStruct AccessorNamingStrategy . You can just extend the DefaultAccessorNamingStrategy and override its isPresenceCheckMethod .

You have access to the method ExecutableElement and you can check the type of class it is in and other things as well.

MyAccessorNamingStrategy extends DefaultAccessorNamingStrategy {

    @Override
    public boolean isPresenceCheckMethod(ExecutableElement element) {
        //You can do your checks here. You can ignore certain methods, from certain classes

    }

Remember to register your SPI with a file META-INF-/services/com.example.MyAccessorNamingStrategy

There is also the examples where you can find an example for the SPI.