Validation Spring confusion to render error message - spring

Question

I try to render error message but it's not appears:
I have validator:
#Component
class ValidatorFBOSSearch implements Validator {
#SuppressWarnings("rawtypes")
#Override
public boolean supports(Class clazz) {
return FormBackObjectSearch.class.equals(clazz);
}
#Override
public void validate(Object obj, Errors error) {
FormBackObjectSearch fbos = (FormBackObjectSearch)obj;
if ("".equals(fbos.particularDate)){
error.rejectValue("particularDate", "required.listOfDates", "This field is required");
}
}
}
it have to cheak does my field in backing object for form have value inputed or not. rejectValue has three param. First - looks for a value in Model Attribute in my backing object, Secong looks for error message in properties file(my properties file located in resourses/error forlder) Third param in methos says if it won't be able to find message in error properties file will render it as default, here is my sniped of code in my servlet-context.xml
<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
<resources mapping="/resources/**" location="/resources/" />
And this my xml config for messageSourse to get errors for Validator in servlet-context.xml:
<!-- Resolves error messages for validator from /Education/src/main/webapp/resources/errors-->
<beans:bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<beans:property name="basename" value="errors/errormessages"/>
</beans:bean>
Here peace of my controller code for dealing with requests:
#RequestMapping(value="/search", method=RequestMethod.GET)
public void search(Model model) {
FormBackObjectSearch fbos = new FormBackObjectSearch();
model.addAttribute("fbosAttribute", fbos);
}
#RequestMapping(value ="/result", method=RequestMethod.POST)
public String extract(#RequestParam String nameOfInstitution,
#RequestParam String particularDate,
#RequestParam String typeOfInstitution,
#ModelAttribute("fbosAttribute") FormBackObjectSearch fbos,
BindingResult result, RedirectAttributes redirectAttributes,
Model model) throws Exception {
ValidatorFBOSSearch validatorFBOS = new ValidatorFBOSSearch();
validatorFBOS.validate(fbos, result);
if(result.hasErrors()) {
redirectAttributes.addFlashAttribute("fbosAttribute", fbos);
return "redirect:/search";
} else {
if(particularDate !="" && nameOfInstitution !="" && typeOfInstitution =="") {
controllerSupportClass.findWithDateAndName(nameOfInstitution, particularDate, model);
} else if(particularDate !="" && nameOfInstitution =="" && typeOfInstitution !="") {
controllerSupportClass.findWithAddedDateAndType(typeOfInstitution, particularDate, model);
} else if(particularDate !="" && nameOfInstitution =="" && typeOfInstitution ==""){
controllerSupportClass.findWithAddedDate(particularDate, model);
} else if(particularDate !="" && nameOfInstitution !="" && typeOfInstitution !="") {
throw new Exception("Search by choose all parameters is not exceptable");
} else {
throw new Exception("You didn't put any search parameters");
}
}
return "search";
}
And here is peace of my jsp:
<form:form action="result" method="post" modelAttribute="fbosAttribute" >
<table>
<tr>
<th>Date for extracting:</th>
<td><form:select path="particularDate">
<form:option value=""> -Choose date-</form:option>
<form:options items="${listOfDates}"></form:options>
</form:select> <td><form:errors path="particularDate" cssClass="error"/></td>
</td>
</tr>
</table>
</form:form>
The problem is thet I can not see error messages show up. I tried to use Flash Attributes to have error appears after riderect, but nothing heppend. cuz I found here that when I use rederect it makes my model and errors deleted and start new one. But How can I have advantage to use flash attibutes to solve my problem. Thank you

Answer 1

To register the validator for an specific controller you need can use the `#InitBimder' annotation.
#InitBinder
protected void initBinder(WebDataBinder binder) {
binder.setValidator(new ValidatorFBOSSearch());
}
For mor details how to register the validator see my answer at:
Validation in Spring MVC
I think your check statement is wrong:
if ("".equals(fbos.particularDate)){
If a user enters nothing, then a String will not be empty ( "" ), it will be null. Therefore use:
if (fbos.particularDate == null || fbos.particularDate.isEmpty())