quarkus: RESTEASY: Unable to find a MessageBodyReader for media type: text/plain; charset=us-ascii and class type java.util.Map

    @POST
    @Path("/import")
    @Consumes({MediaType.MULTIPART_FORM_DATA})
    @Produces({MediaType.APPLICATION_JSON})
    @Transactional
    public Response myFileImport(@MultipartForm MyImportData importData) {
         [...]
    }

---

public class MyImportData {

    @FormParam("myFile")
    @PartType(MediaType.APPLICATION_OCTET_STREAM)
    public InputStream inputStream;

    @FormParam("myMapping")
    @PartType(MediaType.APPLICATION_JSON)
    public Map<Integer, String> myMapping;
}

Exception:

Marcus Biel: java.lang.RuntimeException: RESTEASY007545: Unable to find a MessageBodyReader for media type: text/plain; charset=us-ascii and class type java.util.Map
at org.jboss.resteasy.plugins.providers.multipart.MultipartInputImpl$PartImpl.getBody(MultipartInputImpl.java:226)
at org.jboss.resteasy.plugins.providers.multipart.MultipartFormAnnotationReader.setFields(MultipartFormAnnotationReader.java:189)
at org.jboss.resteasy.plugins.providers.multipart.MultipartFormAnnotationReader.readFrom(MultipartFormAnnotationReader.java:79)
at org.jboss.resteasy.core.interception.jaxrs.AbstractReaderInterceptorContext.readFrom(AbstractReaderInterceptorContext.java:101)
at org.jboss.resteasy.core.interception.jaxrs.ServerReaderInterceptorContext.readFrom(ServerReaderInterceptorContext.java:63)
at org.jboss.resteasy.core.interception.jaxrs.AbstractReaderInterceptorContext.proceed(AbstractReaderInterceptorContext.java:80)

---

media type: text/plain is confusing, since I set APPLICATION_JSON as the type - but it gave me the hint for a quick hack: Putting media type: text/plain and a String Java type, then converting the raw Json String with a Jackson Objectmapper in my Java code myself. I guess I need to provide a custom MessageBodyReader, but I couldn’t get this to work quickly, so I went with my hack instead.