A few minutes ago I found an intricate problem when using Spring MVC. Let’s jump directly to the code:
HomeWebController.java
….
@RequestMapping(method = RequestMethod.POST)
public String login( @Valid LoginRequest login, HttpServletRequest request,
HttpServletResponse response, BindingResult result
) {
request.setAttribute(“home”, login);
logger.info(“binding result=” + result);
if (result.hasErrors()) {
return “home”;
}…
return “feedbacklist”;}
….
home.jsp
….
<form:form commandName=”home” action=”home” class=”form” data-ajax=”false” method=”post”>
<form:errors path=”*” cssClass=”errorblock” element=”div” />
<form:input path=”username” placeholder=”Please enter your email” data-role=”none” class=”field topCurve” autocorrect=”off” autocapitalize=”off” type=”email” pattern=”[^ @]*@[^ @]*” />
<form:password path=”pwd” placeholder=”Please enter your password” data-role=”none” class=”field btnCurve” autocorrect=”off” autocapitalize=”off” />
<form:button class=”button rounded” id=”submithome” data-role=”none” type=”submit”>Submit</form:button>
</form:form>
After a few hours searching in the web, I found the answer.
There are 2 small thing are incorrect in the code above:
1. BindingResult parameter must be placed immediately after validated bean.
public String login( @Valid LoginRequest login, BindingResult result, HttpServletRequest request,
HttpServletResponse response
)
This is one of the Spring weakness. Spring is very rigid in the naming and parameter.
If we didn’t follow this, the following exception will occur:
org.springframework.validation.BindException: org.springframework.validation.BeanPropertyBindingResult: 1 errors
2. Naming in the jsp “<form:form commandName= …” and controller must according to the Bean Class.
Let say our java bean class is: “LoginRequest”, then we MUST name commandName attributes as “loginRequest”.
following is the correction:
home.jsp
<form:form commandName=”loginRequest” action=”home” class=”form” data-ajax=”false” method=”post”>
HomeWebController.java
@RequestMapping(method = RequestMethod.POST)
public String login( @Valid LoginRequest login, BindingResult result, HttpServletRequest request,
HttpServletResponse response) {
request.setAttribute(“loginRequest”, login);
logger.info(“binding result=” + result);
if (result.hasErrors()) {
return “home”;
}
…
return “/feedbacklist”;
}
Intricate huh?
andytanoko 