How pass params to custom error message in JHipster?

问题

I m still learning JHipster, So today I though about making somme validation exerices by my self, and to try to send meaningfull error messages to my frontend

Here is what I tried

In my controller I have the following :

/**
 * POST  /lessons : Create a new lesson of 45 min.
 * 
 * if lesson is of type creno or circulation the car is mandatory
 *
 * @param lessonDTO the lessonDTO to create
 * @return the ResponseEntity with status 201 (Created) and with body the new lessonDTO, or with status 400 (Bad Request) if the lesson has already an ID
 * @throws URISyntaxException if the Location URI syntax is incorrect
 */
@PostMapping("/lessons")
public ResponseEntity<LessonDTO> createLesson(@Valid @RequestBody LessonDTO lessonDTO) throws URISyntaxException {
    log.debug("REST request to save Lesson : {}", lessonDTO);
    if (lessonDTO.getId() != null) {
        throw new BadRequestAlertException("A new lesson cannot already have an ID", ENTITY_NAME, "idexists");
    }
    if(!lessonService.checkLessonTime(lessonDTO)){
        return ResponseEntity.badRequest().headers(HeaderUtil.createFailureAlert(ENTITY_NAME,"EK_L_C01", "erreur de requete dupliquer")).build();
    }
    LessonDTO result = lessonService.save(lessonDTO);
    return ResponseEntity.created(new URI("/api/lessons/" + result.getId()))
        .headers(HeaderUtil.createEntityCreationAlert(ENTITY_NAME, result.getId().toString()))
        .body(result);
}

as you see if the check lesson time fails I have to send a bad request response with failure code EK_L_C01 then my next step ws to make a little change in the front end where I got to make this

save() {
    this.isSaving = true;
    this.lesson.dateLesson = this.dateLesson != null ? moment(this.dateLesson, DATE_TIME_FORMAT) : null;
    if (this.lesson.id !== undefined) {
        this.subscribeToSaveResponse(this.lessonService.update(this.lesson));
    } else {
        this.subscribeToSaveResponse(this.lessonService.create(this.lesson));
    }
}

protected subscribeToSaveResponse(result: Observable<HttpResponse<ILesson>>) {
    result.subscribe((res: HttpResponse<ILesson>) => this.onSaveSuccess(), (res: HttpErrorResponse) => this.onSaveError(res.message));
}

protected onSaveSuccess() {
    this.isSaving = false;
    this.previousState();
}

protected onSaveError(errorMessage: string) {
    this.isSaving = false;
    this.onError(errorMessage);
}

protected onError(errorMessage: string) {
    this.jhiAlertService.error(errorMessage, null, null);
}

then I added the translation of the code in my global.json as below

"error": {
        "internalServerError": "Erreur interne du serveur",
        "server.not.reachable": "Serveur inaccessible",
        "url.not.found": "Non trouvé",
        "NotNull": "Le champ {{fieldName}} ne peut pas être vide !",
        "Size": "Le champ {{fieldName}} ne respecte pas les critères minimum et maximum !",
        "userexists": "Login déjà utilisé !",
        "emailexists": "Email déjà utilisé !",
        "idexists": "Une nouvelle entité {{entityName}} ne peut pas avoir d'ID !",
        "idnull": "Invalid ID",
        "EK_L_C01": "Impossible de reserver une lesson : nombre maximal de lesson attein {{dateLesson}} "
    },

I have my message displayed but there is no date value.

As you see I want to mention the date used as error message variable but I dont know how, so How can I add this date value to my error message ?

回答1:

Hi After a full day of code swimming I did found that Jhipster have already made a error handling mechanisme in the web/rest/errors package it is full of Throwable that seems to be handy, for my case it was CustomParameterizedException

What I did was simple

First My controller create lesson became :

@PostMapping("/lessons")
public ResponseEntity<LessonDTO> createLesson(@Valid @RequestBody LessonDTO lessonDTO) throws URISyntaxException {
    log.debug("REST request to save Lesson : {}", lessonDTO);
    if (lessonDTO.getId() != null) {
        throw new BadRequestAlertException("A new lesson cannot already have an ID", ENTITY_NAME, "idexists");
    }
    if(!lessonService.checkLessonTime(lessonDTO)){
        throw new CustomParameterizedException("error.EK_L_C01", lessonDTO.getDateLesson().toString());
    }
    LessonDTO result = lessonService.save(lessonDTO);
    return ResponseEntity.created(new URI("/api/lessons/" + result.getId()))
        .headers(HeaderUtil.createEntityCreationAlert(ENTITY_NAME, result.getId().toString()))
        .body(result);
}

then my global.json was updated as follow

"error": {
        "internalServerError": "Erreur interne du serveur",
        "server.not.reachable": "Serveur inaccessible",
        "url.not.found": "Non trouvé",
        "NotNull": "Le champ {{fieldName}} ne peut pas être vide !",
        "Size": "Le champ {{fieldName}} ne respecte pas les critères minimum et maximum !",
        "userexists": "Login déjà utilisé !",
        "emailexists": "Email déjà utilisé !",
        "idexists": "Une nouvelle entité {{entityName}} ne peut pas avoir d'ID !",
        "idnull": "Invalid ID",
        "EK_L_C01": "Impossible de reserver une lesson : nombre maximal de lesson attein pour la date {{param0}} "
    },

This way when the checkLessonTime fails I m getting the desired error message with parameters

Thanks for the interest, wish this help others new to jhipster.

For more details read the class code of CustomParameterizedException.

来源：https://stackoverflow.com/questions/55133059/how-pass-params-to-custom-error-message-in-jhipster