How to return error status and validation errors from this Spring MVC controller?

Question

I have an action method defined this way in one of my controllers:

@RequestMapping(method = RequestMethod.POST) public @ResponseBody Post create(@Valid Post post, BindingResult bindingResult) { if (bindingResult.hasErrors()) { // how to return an error status + error messages from here? } else { postRepository.persist(post); return post; } } 

When the message is saved successfully, I return the message back to the client. But when it has validation errors, I want to return the error status code, as well as all validation error messages, back to the client.

What is the best way to do this?

Answer 1

The sine that you plan to use the REST api, you need to create your own Pojo (aka. Resource), which will be odd behavior or validation errors, as indicated by horaceman. I will show you how we do this in our application.

Since we use JSON as a representation of the data, we want the following information if an unexpected exception occurs.

 { "status" : "EXCEPTION", "exceptionName" : "MyCustomException", "exceptionMsg" : "ex.unsupportedOperation" } 

This, of course, is an example. A good solution is that we can consider exceptionMsg as a key in our interface to display the correct i18n message or display it to the user as is (in this case we use more descriptive messages).

Now that everything is all right, we are doing something like this:

 { "status" : "OK", "data" : {(...)} } 

Element

Data is optional. We can send everything we need to notify the interface, or skip it completely.

The final scenario will be yours - validation errors. In this case, we usually send the following content:

 { "status" : "VALIDATION_FAILED", "errors" : [ "fieldName" : "username", "errorCode" : "validation.requiredField", "errorMsg" : "Username is required."] } 

Thus, it is obvious that the API clients will receive information that the verification failed, and in the appropriate fields, accurate information about what went wrong. Of course, errors is an array (or List ), so we always provide as much detail as necessary.

How am i doing this? Easy, these objects are simple POJOS that translate to JSON using Jackson. This gives me unlimited JSON presentation capabilities. What I am doing, I am ready by POJO to present validation errors (for example) and add it as a Model to my ModelAndView instance. Then I just rely on Spring for proper JSON marshaling.

In your case, you have an @ResponseBody annotation with your Post instance, as far as I know, you cannot do this. Your setup says, “Well, no matter what happens, always return an instance of Post.” What you have to do is replace it with a simple ModelAndView , provide it with the correct Model based on validation, and return it to the client API.

Answer 2

I think you want to make an ajax call in your controller. you return a post object in a method, so it is not possible to return another object (for example, an error message with code). what about return instead of ExecutionResult?

 ExecutionResult{ private int statusCode; private String message; private Object yourPost; //get and set methods here... } 

Answer 3

For @ResponseBody, I would remove BindigResult from the method signature and throw a BindException. Then I used the @ExceptionHandler method to return an object that contains the errors described by Likacz.

 @RequestMapping(method = RequestMethod.POST) public @ResponseBody Post create(@Valid Post post) { postRepository.persist(post); return post; } @ExceptionHandler public ValidationErrors handleException(BindException ex) { // ... } 

Answer 4

Похоже, вы уже получили свой первый ответ. Looks like you already got your first answer. На "других способах" привязать событие click, если вы не указали имя класса, существует несколько вариантов. On "other methods", to bind the click event, if you did not specify the class name, there are several options. Вы можете добавить id к тегу и называть его таким образом. You can add id to the tag and call it that way. Или, если вы не хотите добавлять класс или идентификатор, вы можете использовать синтаксис привязки данных со встроенной привязкой "click" для вызова метода на вашей модели представления (очевидно, это не стиль jquery evnet, так что до вас, как вы хотите подключить свои мероприятия). Or, if you do not want to add a class or identifier, you can use the data binding syntax with the built-in "click" binding to call the method on your view model (obviously, this is not the jquery evnet style, so it's up to you how you want to connect your events ) Вот так: Like this:

 Click me 

Answer 5

Вы получаете какие-либо ошибки? Are you getting any errors?

Загрузили ли вы jQuery.js и knockout.js Have you jQuery.js and knockout.js

отправьте код модели просмотра. send view model code.

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ах! Oh! у вас есть опечатка you have a typo

 $(document).on("click", ".button-delete", function() { // console.log("inside"; <-- here it is console.log("inside"); }); 

DEMO Demo

Answer 6

Наир сначала сообщит мне, что вы хотите сделать здесь если вы хотите удалить кнопку, работает. Nair first tells me what you want to do here if you want to remove the button, it works. затем используйте функцию удаления jquery Ui, и если вы хотите что-то консоль, то просто напишите console.log( "вы хотите консоль" ); then use the jquery Ui delete function, and if you want something console, then just write console.log ("you want a console");

Я думаю, что ваша строка function() { console.log("inside"; }); is wrong I think your line is function() { console.log("inside"; }); is wrong function() { console.log("inside"; }); is wrong . function() { console.log("inside"; }); is wrong .

Answer 7

Я бы рекомендовал вам взглянуть на привязку клика для нокаута, а не на смешивание нокаута со случайным запросом. I would recommend that you take a look at the click binding for a knockout, rather than mixing a knockout with a random request. Связывание кликов позволит вам привязать событие click к функции в модели представления. Linking clicks allows you to bind the click event to a function in the view model.