[JAVA][RxJava][Retrofit2] Query parameters are generated as path parameters

Description

The Java code generator is generating Query parameters as if they were path parameters.

Swagger-codegen version

3.0.8

Swagger declaration file content or url

/Reference/Countries:
    get:
      tags:
        - Reference
      description: 'TODO: Add Description'
      operationId: CountryDialingCodesGet
      parameters:
        - name: CountryCode
          in: query
          description: ''
          required: false
          style: form
          explode: true
          schema:
            type: string
        - name: CountryName
          in: query
          description: ''
          required: false
          style: form
          explode: true
          schema:
            type: string

Command line used for generation

java -jar swagger-codegen-cli-3.0.8.jar generate -i "custom.json" -l java -o samples/client/java --library retrofit2 -c "swagger_rxjava_config.json"

With the config being:

{
  "library": "retrofit2",
  "artifactId": "swagger-petstore-retrofit2-rx2",
  "useRxJava": true,
  "hideGenerationTimestamp": true
}

And this is the generated code:

public interface ReferenceApi {
  /**
   * 
   * TODO: Add Description
   * @param countryCode  (optional)
   * @param countryName  (optional)
   * @return Call<CountryDialingCodes>
   */
  @GET("Reference/Countries")
  Observable<CountryDialingCodes> countryDialingCodesGet(
          @Path("CountryCode") String countryCode, @Path("CountryName") String countryName
  );
}

Suggest a fix/enhancement

The generated code should have

@Query

instead of

@Path

Run the shown swagger-codegen CLI command with custom.json, the Java generator, and the retrofit2 library, using swagger_rxjava_config.json. Inspect the generated ReferenceApi interface and trace the parameter annotation generation; done means the query parameters use @Query instead of @Path.