How to do server side validation in spring mvc using validator class - spring

Question

Hi am new to spring mvc i have to do sever side validation using separate validator class. i have two model with one to many relation i have to register them before register them i am new server side validation in spring mvc to use spring form and all
<form id="studentEnrollmentForm" method="post" class="form-horizontal" action="saveStudentByAdmin">
<div class="form-group">
<label class="col-xs-2 control-label">Student Full Name</label>
<div class="group">
<div class="col-xs-3">
<input type="text" class="form-control" name="studentFirstName" id="fn" placeholder="First name" />
</div>
</div>
<div class="col-xs-3">
<input type="text" class="form-control" name="studentMiddleName" placeholder="Middle name" />
</div>
<div class="col-xs-3">
<input type="text" class="form-control" name="studentLastName" placeholder="Last name" />
</div>
</div>
<div class="form-group">
<label class="col-xs-2 control-label">Parents Full Name</label>
<div class="col-xs-3">
<input type="text" class="form-control" name="parentFirstName" placeholder="First name" />
</div>
<div class="col-xs-3">
<input type="text" class="form-control" name="parentMiddleName" placeholder="Middle name" />
</div>
<div class="col-xs-3">
<input type="text" class="form-control" name="parentLastName" placeholder="Last name" />
</div>
</div>
<div class="form-group">
<label class="col-xs-2 control-label">Date-of-birth</label>
<div class="col-xs-3 ">
<div class="input-group input-append date" id="studentDOB">
<input type="Text" class="form-control" name="studentDOB" /> <span
class="input-group-addon add-on"><span
class="glyphicon glyphicon-calendar"></span></span>
</div>
</div>
<label class="col-xs-3 control-label">Gender</label>
<div class="col-xs-3">
<div class="btn-group" data-toggle="buttons">
<label class="btn btn-default">
<input type="radio" name="studentGender" value="male" />Male</label>
<label class="btn btn-default">
<input type="radio" name="studentGender" value="female" />Female</label>
</div>
</div>
</div>
<div class="form-group">
<label class="col-xs-2 control-label">Phone</label>
<div class="col-xs-3">
<input type="text" class="form-control" name="parentPhoneNumber" placeholder="Phone number" />
</div>
<label class="col-xs-3 control-label">Email</label>
<div class="col-xs-3">
<input type="text" class="form-control" name="parentEmail" placeholder="Email" />
</div>
</div>
<div class="form-group">
<label class="col-xs-2 control-label">Permanent Address</label>
<div class="col-xs-3">
<textarea class="form-control" rows="3" name="studentPermanentAddress" /></textarea>
</div>
<label class="col-xs-3 control-label">Present Address</label>
<div class="col-xs-3">
<textarea class="form-control" rows="3" name="studentPresentAddress" /></textarea>
</div>
</div>
<div class="form-group">
<label class="col-xs-2 control-label">Class to join</label>
<div class="col-xs-3">
<!-- <input type="text" class="form-control" name="className" placeholder="Enter Class" /> -->
<select name="className" class="form-control">
<option value="">Select class </option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
<option value="6">6</option>
<option value="7">7</option>
<option value="8">8</option>
<option value="9">9</option>
<option value="10">10</option>
</select>
</div>
</div>
<div class="form-group">
<div class="col-xs-1 ">
<button type="submit" class="btn btn-primary ">Submit</button>
</div>
<div class="col-xs-1 ">
<button type="reset" class="btn btn-default" id="rstbutton">Refresh</button>
</div>
</div>
</form>
Controller
#Controller
#RequestMapping("/")
public class AdminRegistrationController {
#Autowired
private IAdminRegistrationService adminRegistrationService;
#RequestMapping(value = "/register", method = RequestMethod.GET)
public String viewRegistrationPage(Model model) {
StudentDTO studentDTO = new StudentDTO();
ParentDTO pdto=new ParentDTO();
model.addAttribute("teacherDTO", studentDTO);
model.addAttribute("teacherDTO", pdto);
return "StudentEnrollmentByAdmin";
}
#RequestMapping(value = "/saveStudentByAdmin", method = RequestMethod.POST)
public String saveTeacherByAdmin(#ModelAttribute StudentDTO sdto,#ModelAttribute ParentDTO pdto) {
System.out.println(sdto.getStudentFirstName());
System.out.println(pdto.getParentFirstName());
return "redirect:/register"; // this line redirecting to above method to avoid same data insertion again when i press f5
//return "TeacherEnrollmentByAdmin"; To know duplication insertion comment above line and above method current this line
//when you get response page(after insertion of data) press f5 and see in data base
}
}
My Example validator class
#Component
public class StudentRegistrationFromAdminValidator implements Validator{
public boolean supports(Class<?> clazz) {
return StudentDTO.class.isAssignableFrom(clazz);
//return ParentDTO.class.isAssignableFrom(clazz);
}
public void validate(Object target, Errors errors) {
StudentDTO student = (StudentDTO)target;
ParentDTO parent = (ParentDTO)target;
String studentFirstName = student.getStudentFirstName();
String parentFirstName=parent.getParentFirstName();
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "studentFirstName", "student.studentFirstName.empty");
ValidationUtils.rejectIfEmptyOrWhitespace(errors, "parentFirstName", "parent.parentFirstName.empty");
if(studentFirstName.equals("pradee")){
errors.rejectValue("studentFirstName", "student.studentFirstName.invalid");
}
if(parentFirstName.equals("pradee")){
errors.rejectValue("parentFirstName", "parent.parentFirstName.invalid");
}
}
}

Answer 1

In StudentDTO and ParentDTO classes, you can give various validator annotations from javax.validation.constraints package and org.hibernate.validator.constraints package(if using hibernate).
public class StudentDTO {
#Size(min=6, max=12)
private String firstName;
#Size(min=6, max=12)
private String lastName;
//getter setter
}
Then add javax.validation.Valid annotation and
org.springframework.validation.BindingResult interface in controller method as follows.
#RequestMapping(value = "/saveStudentByAdmin", method = RequestMethod.POST)
public String saveTeacherByAdmin(#Valid #ModelAttribute StudentDTO sdto,#ModelAttribute ParentDTO pdto,
BindingResult bindingResult) {
if(bindingResult.hasErrors()) {
System.out.println(bindingResult.getAllErrors().get(0).getDefaultMessage());
}
}