java - 如何处理 RESTful Spring MVC Controller 中的验证错误和异常？

Question

例如，如何处理此 Controller 操作方法中的验证错误和可能的异常:

@RequestMapping(method = POST)
@ResponseBody
public FooDto create(@Valid FooDTO fooDto, BindingResult bindingResult) {
    if (bindingResult.hasErrors()) {
        return null; // what to do here?
                     // how to let the client know something has gone wrong?
    } else {
        fooDao.insertFoo(fooDto); // What to do if an exception gets thrown here?
                                  // What to send back to the client?
        return fooDto;
    }
}

Answer 1

出错就抛异常，然后用@ExceptionHandler to annotate another method然后它将处理异常并呈现适当的响应。