Validation in Spring MVC

Question

如何在验证器类中获取请求对象，因为我需要验证内容，即请求对象中存在的参数。

Answer 1

You have two choices:

• JSR 303 (Bean Validation) Validators
• Spring Validators

---

For JSR 303 you need Spring 3.0 and must annotate your Model class with JSR 303 Annotations, and write an @Valid in front of you parameter in the Web Controller Handler Method. (like Willie Wheeler show in his answer ). Additionaly you must enable this functionality in the configuration:

<!-- JSR-303 support will be detected on classpath and enabled automatically -->
<mvc:annotation-driven/>

---

For Spring Validators , you need to write your Validator (see Jigar Joshi's answer ) that implements the org.springframework.validation.Validator Interface. The you must register your Validator in the Controller. In Spring 3.0 you can do this in a @InitBinder annotated Method, by using WebDataBinder .setValidator ( setValidator it is a method of the super class DataBinder )

Example (from the spring docu)
@Controller
public class MyController {

    @InitBinder
    protected void initBinder(WebDataBinder binder) {
        binder.setValidator(new FooValidator());
    }

    @RequestMapping("/foo", method=RequestMethod.POST)
    public void processFoo(@Valid Foo foo) { ... }
}

For more details, have a look at the Spring reference, Chapter 5.7.4 Spring MVC 3 Validation .

BTW: in Spring 2 there was someting like a setValidator property in the SimpleFormController.

Answer 2

Using simple validator (your custom validator) You don't need request object to get param there in Validator. You can directly have it from.

For example : This will check field from request with name name and age

public class PersonValidator implements Validator {

    /**
    * This Validator validates just Person instances
    */
    public boolean supports(Class clazz) {
        return Person.class.equals(clazz);
    }

    public void validate(Object obj, Errors e) {
        ValidationUtils.rejectIfEmpty(e, "name", "name.empty");
        Person p = (Person) obj;
        if (p.getAge() < 0) {
            e.rejectValue("age", "negativevalue");
        } else if (p.getAge() > 110) {
            e.rejectValue("age", "too.darn.old");
        }
    }
}

Also See

• Document

Answer 3

Not 100% sure I'm following your question correctly, but with Spring MVC, you pass the object into the method and annotate it (at least with Spring 3), like so:

@RequestMethod(value = "/accounts/new", method = RequestMethod.POST)
public String postAccount(@ModelAttribute @Valid Account account, BindingResult result) {
    if (result.hasErrors()) {
        return "accounts/accountForm";
    }

    accountDao.save(account);
}

The relevant annotation here is @Valid, which is part of JSR-303. Include the BindingResult param as well so you have a way to check for errors, as illustrated above.

Answer 4

You could easily add another method with HttpServletRequest parameter.

 public void validateReq(Object target, Errors errors,HttpServletRequest request) {

       // do your validation here
}

Note that you are not overriding a method here

Answer 5

I also have the same issue when i use spring validator validate captcha. In the validator implementor, i want to get the correct-captcha from HttpSession(from HttpServletRequest get HttpSession).

Not found any good codes for get it in validator, so bad!!!

There are some compromise proposal as follow:

1. In the binding form DTO add an additional field (call: correctCaptcha), in the Controller method set the field value from HttpSession , then you can validate in the validator

    public class UserRegisterDto { private String correctCaptcha; //getter,setter } 

2. Add the HttpServletRequest reference in the binding form DTO, then can use it in the validator.

    public class UserRegisterDto { private HttpServletRequest request; //getter ,setter } @RequestMapping(value = "register.hb", method = RequestMethod.POST) public String submitRegister(@ModelAttribute("formDto") @Valid UserRegisterDto formDto, HttpServletRequest request,BindingResult result) { formDto.setRequest(request); if (result.hasErrors()) { return "user_register"; } }