Question

I’ve a jsp page which is like this:

<form:form action="userRegistration" name="userRegistrationForm" commandName="userRegistration">

<form:input path="userName"/>
<form:input path="houseNo"/>

</form:form>

and all the required fields.

In controller I use like this:

@RequestMapping(method=RequestMethod.GET)
public String registration(ModelMap model,HttpSession session) {
    UserRegistration userRegistration = service.createUserRegistration();
    model.addAttribute("userRegistration",userRegistration);
    return "registrationview";
}


@RequestMapping(method=RequestMethod.POST)
public String getRegistration(UserRegistration userRegistration, HttpSession session, ModelMap model) {
    boolean result = validateAndSaveData(userRegistration);
    if (result){

    }
}

when the user submits the form, it comes to the post and then validates the input and saves it.
How can I send a succes message and error message to the view. Is there any changes required in the existing implementation ?

Answer 1

@RequestMapping(method=RequestMethod.POST)
public String getRegistration(UserRegistration userRegistration, HttpSession session, ModelMap model) {
    boolean result = validateAndSaveData(userRegistration);
    if (result){
        model.addAttribute("successMsg", "Form successfully submitted");
        return "successPage";
    }
    else {
        model.addAttribute("errorMsg", "Your form submission contains errors.");
        return "formPage";  
    }
}

I agree with Shagaan that you should look into using Spring’s built-in support for JSR-303 validation to validate the form. Here’s a little info on how to do that. First, annotate your form with JSR-303 (javax.validation) annotations:

public class UserRegistration {

    @NotNull
    @Size(max=7)
    private String name;
    @Min(0)
    private int houseNo;
    ...
}

Then annotate your model in the controller method with “@Valid”:

@RequestMapping(method=RequestMethod.POST)
public String getRegistration(@Valid UserRegistration userRegistration, BindingResult result, HttpSession session, ModelMap model) {
    if (result.hasErrors()){
        model.addAttribute("errorMsg", "Your form submission contains errors.");
        return "formPage"; 
    }

    model.addAttribute("successMsg", "Form successfully submitted");
    return "successPage";
}

Spring’s BindingResult automatically binds the errors to your form object, so then in your jsp, you could do:

<form:form action="userRegistration" name="userRegistrationForm" commandName="userRegistration">

    <form:input path="userName"/> <form:errors path="userName" cssClass="error"/>
    <form:input path="houseNo"/>  <form:errors path="houseNo" cssClass="error"/>

</form:form>

To use Spring validation, you need Validation-api (JSR-303 spec) and an implementation (Hibernate-Validator) in your classpath. See Section 6.7 of Spring validation docs