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javaswaggerswagger-uispringfox

SwaggerUI Response Examples do not work with mediaType JSON

It seems that there is a bug in SwaggerUI because as soon as I set the mediaType of @ExampleProperty to application/json the example value is empty as you can see here:

enter image description here

I've tried several ways but none is working. According to this it seems to be a popular problem: https://github.com/springfox/springfox/issuesW/2352

I've tried an unlogical solution (does not work):

  @ApiOperation(
      value = "Sends a request to the AiController to predict the request",
      produces = "application/json",
      consumes = "application/json",
      authorizations = @Authorization(value = "Bearer"))
  @ApiResponses(
      value = {
        @ApiResponse(
            code = 200,
            message = "Successfully retrieved predictions",
            examples =
                @Example(
                    value = {@ExampleProperty(mediaType = "application/json", value = "test")}))

Another one (also not working):

  @ApiOperation(
      value = "Sends a request to the AiController to predict the request",
      produces = "application/json",
      consumes = "application/json",
      authorizations = @Authorization(value = "Bearer"))
  @ApiResponses(
      value = {
        @ApiResponse(
            code = 200,
            message = "Successfully retrieved predictions",
            examples =
                @Example(
                    value = {
                      @ExampleProperty(
                          mediaType = "application/json",
                          value = "{\"code\" : \"42\", \"message\" : \"Invalid ID supplied\"}")
                    }))

A simpler version (not working):

  @ApiResponses(
      value = {
        @ApiResponse(
            code = 200,
            message = "Successfully retrieved predictions",
            examples =
                @Example(
                    value = {
                      @ExampleProperty(
                          value = "{'property': 'test'}",
                          mediaType = "application/json")
                    }))

But as soon that I change the mediaType to don't have a specific type it works:

  @ApiResponses(
      value = {
        @ApiResponse(
            code = 200,
            message = "Successfully retrieved predictions",
            examples =
                @Example({
                  @ExampleProperty(
                      mediaType = "*/*",
                      value = "{\n\"predictions\": [ \n \"cat\" \n]\n}")
                }))

Output is:

{
"predictions": [ 
 "cat" 
]
}

Thats nearly what I want to have but of course the indentation is wrong.

Is there any other way to do an @ApiResponseexample? Can't I give an example with my DTO (?):

@ApiModel(
    value = "Cat or Dog response",
    description = "Response of the prediction whether it's a cat or dog")
@Data
public class CatOrDogResponse {

  @ApiModelProperty(value = "Images to predict", example = "test", required = true)
  private String[] predictions;
}

My used Spring Fox versions:

compile group: 'io.springfox', name: 'springfox-swagger2', version: '3.0.0'
compile group: 'io.springfox', name: 'springfox-swagger-ui', version: '3.0.0'
compile group: 'io.springfox', name: 'springfox-boot-starter', version: '3.0.0'
compile group: 'io.springfox', name: 'springfox-data-rest', version: '3.0.0'
compile group: 'io.springfox', name: 'springfox-bean-validators', version: '3.0.0'
Solution

  • In the end the answer is easy. I found this on GitHub: https://github.com/springfox/springfox/issues/2538#issuecomment-637265748

    The bug should be fixed but it's still not fixed. To get the example value working for responses the annotation of the REST type needs to be adjusted:

    @PostMapping(value = "/predict", produces = "application/json", consumes = "application/json")

    I give you a concrete example with my methods:

    @ApiOperation(value = "Sends a request to the AiController to predict the request", response =
            CatOrDogResponse.class, authorizations = @Authorization(value = "Bearer"))
    @ApiResponses(value = {@ApiResponse(code = 200, message = "Successfully retrieved predictions"),
            @ApiResponse(code = 401, message = "You are not authorized to send a request"), @ApiResponse(code = 403,
            message = "Accessing the resource you were trying to reach is forbidden"), @ApiResponse(code = 404,
            message = "The resource you were trying to reach is not found")})
    @PostMapping(value = "/predict", produces = "application/json", consumes = "application/json")
    public Mono<CatOrDogResponse> predict(@RequestHeader HttpHeaders headers, @ApiParam(name = "Cat or Dog Prediction "
            + "Request", value = "Parameters for predicting whether an image or multiple images is/are a cat or dog") @Valid @RequestBody CatOrDogRequest catOrDogRequest) {
      ...
    }

    Important is that you define the response class in the @ApiOperation like me: response = CatOrDogResponse.class

    In the response class you define the example value for the response:

    @ApiModel(value = "Cat or Dog response", description = "Response of the prediction whether it's a cat or dog")
@Data
public class CatOrDogResponse {

    @ApiModelProperty(value = "Images to predict", example = "cat")
    private String[] predictions;
}

    What changed now is that finally automatically the response type is declared as application/json instead of */*. The correct indentation works automatically. And as you can see I'm not using produces and consumes in the @ApiOperation anymore because it's useless.

    enter image description here