IntelliJ Idea mapstruct java: Internal error in the mapping processor: java.lang.NullPointerException

Question

After upgrading to the version 2020.3 of Idea i get a NullPointerException for the mapping processor. If anybody has a clue... Thank you!

Lethargic

Answer 1

The solution is to update MapStruct to 1.4.1.Final or later version, see this issue for more details.

You can also add -Djps.track.ap.dependencies=false at File | Settings (Preferences on macOS) | Build, Execution, Deployment | Compiler | Build process VM options as a workaround.

Ailin

After upgrading Mapstruct to 1.4.1.Final I am getting another issue which I did not get with 1.3 - "No method found annotated with @Named#value". Has anyone faced this problem yet? – Centime

You just need to add the @Named annotation over the method and qualifiedByName where it was used. – Overseer

IDE should not be the driver to force lib update on a project. – Pronunciamento

Thanks, adding -Djps.track.ap.dependencies=false really helped me! – Kehr

After upgrading Mapstruct to 1.4.1.Final I am getting another issue which I did not get with 1.3 - "No method found annotated with @Named#value", and i have this method in parent class (inheritance). these methods are there for long time – Anselmi

I would add : also update mapstruct-processor to 1.4.1.Final or later version – Hemorrhoidectomy

We have the same problem with mapstruct 1.2 Final on windows, if we run the test directly on the java class. -Djps.track.ap.dependencies=false fix our problem. – Prescind

Answer 2

If you cannot update MapStruct (my case), details here.

You have to find the exact place where put the -Djps.track.ap.dependencies=false setting (and I had hard time to figure out where).

So, as they say, a picture is worth a thousand words:

Preferences --> Build, Execution, Deployment --> Compiler

Kallick

flawless answer @Kallick – Script

Answer 3

There are several intellij bugs here. If I change the maven version 1.3.0.Final to 1.4.1.Final the intellij don't want to update the version.

Solution

1. Upgrade the maven version to 1.4.1.Final
2. Delete manually mapstruct 1.3.1.Final from External Libraries(Project Structure | Libraries)
3. mvn clean package
4. Click reload all maven projects

It works without -Djps.track.ap.dependencies=false

If you have swagger exclude mapstruct first:

<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>${swagger2.version}</version>
<exclusions>
    <exclusion>
        <groupId>org.mapstruct</groupId>
        <artifactId>mapstruct</artifactId>
    </exclusion>
</exclusions>

Formenti

Manually removing the old version from the external libraries and reloading the Maven projects worked for me. – Unaunabated

Answer 4

Expanding on freedev's answer. For windows users the following will be the place to go :

1. Click on the settings gear icon on the right.
2. Go to settings (ctrl+A+S is a good shortcut to get here).
3. Find Compiler under Build,Execution, Deployment in the left menu
4. Add -Djps.track.ap.dependencies=false in User-local build process VM options

Daugava

Answer 5

In my case, I made these changes and it works perfectly for me.

Then I just deleted the caches and rebuilt the entire project, maybe it wasn't necessary but that worked for me.

Fortier

Answer 6

In my case my build.gradle was misconfigured. I used some Mapstruct SPI AccessorNamingStrategy in two separat projects (command and custom-mapper) which I included twice in annotationProcessor of the build gradle. My solutions was to remove one of the annotations and it worked.

Threaten