MapStruct not generating Component for mapper implementation

[Stork89]

Hello,

I am in the middle of learning spring in an online course and one of the course parts uses MapStruct.

Unfortunately I fail to start spring boot because of failed dependency (Bean cannot be injected because no impl was found).

I looked into generated sources and it turns out that MapperImpl has a missing @Component annotation. The course instructor also showed generated source of the mapper which had @Component attached to the implementation.

The source code can be found here: git clone https://github.com/springframeworkguru/spring5-mvc-rest.git

The branch that is causing the problem: category-controller

My OS: win10

IDE: idea pro 2017.3

MapStruct ver: 1.2.0.Final

The generated code I get:

@Generated(
    value = "org.mapstruct.ap.MappingProcessor",
    date = "2018-03-22T22:24:43+0100",
    comments = "version: 1.2.0.Final, compiler: javac, environment: Java 1.8.0_131 (Oracle Corporation)"
)
public class CategoryMapperImpl implements CategoryMapper {

    @Override
    public CategoryDTO categoryToCategoryDTO(Category category) {
        if ( category == null ) {
            return null;
        }

        CategoryDTO categoryDTO = new CategoryDTO();

        categoryDTO.setId( category.getId() );
        categoryDTO.setName( category.getName() );

        return categoryDTO;
    }
}

I checked the documentation and seems everything is correctly setup in pom (well, the instructor used the same code and it works on his side).

How can I force Mapper implementation to have @Component annotation?

[Andreas Gudian]

The easiest way to make sure of that is to use the componentModel attribute in the @Mapper annotation (or @MapperConfig). 

That will make you more independent from quirks with IDEs that may or may not pull in the compiler processor options ;-).

--
You received this message because you are subscribed to the Google Groups "mapstruct-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to mapstruct-use...@googlegroups.com.
To post to this group, send email to mapstru...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Stork89]

Andreas, thank you for the hint. It actually solves my issue.

I also had a look into pom.xml and found a way of making it work.

I actually had following lines in pom for maven-compiler-plugin:

<compilerArgs>
    <compilerArg>-Amapstruct.defaultComponentModel=spring</compilerArg>
</compilerArgs>

and changing this to 

<compilerArgs>
    <arg>-Amapstruct.defaultComponentModel=spring</arg>
</compilerArgs>

makes @Component in the generated mapper. Not sure why but it works :)...

[Filip Hrisafov]

In case you are using IntelliJ be aware that your compiler arguments will not be picked up by IntelliJ when building your code. Have a look at IDEA-143742 for more information