Ignore field from bindingResult validation - spring-boot

Question

I'm using SpringBoot 2.1.3 (Embedded Tomcat) + Thymeleaf 3 + java 8. I have a problem regarding validation of a UserDTO that is similar to follow:
#Data
public class UserDTO {
#NotNull
private String name;
#NotNull
private String surname;
.....
#NotBlank
#Email
#UniqueEmailConstraint // this is a custom validator
private String email;
#NotNull
private String pass;
.......
}
#UniqueEmailConstraint check inside the DB if the email is present or not (just one email for account are admitted). Than I have 2 controller, one for inserting user and another one for updating user
#PostMapping("/save-user")
String saveUser(#ModelAttribute("userDTO") #Valid UserDto userDto, BindingResult bindingResult, Model model) {
if (bindingResult.hasErrors()) {
return "fragment/form-user";
}
and similar one with some other function:
#PostMapping("/update-user")
String updateUser(#ModelAttribute("userDTO") #Valid UserDto userDto, BindingResult bindingResult, Model model) {
if (bindingResult.hasErrors()) {
return "fragment/form-user";
}
The problem is that when I selecting a user to modify it, a thymeleaf view is open and show me all data inserted as expected (mail included). If I try to modify another field, for example Address and click submit my controller show an errors because it find the email on DB.
Question is, is there a way to ignore certain field on bindingResult? Because of I would like to ignore the #UniqueMailConstraint error on second controller Validation.
Thanks all

Answer 1

I had the a similar problem hope this helps:
Lets say there is an employee HTML form with two buttons.
One of the buttons should validate the whole form, another button should validate just one single field and ignore the validation for the rest.
#RequestMapping(method = RequestMethod.POST, value = "saveEmployee", params = "action=save")
public ModelAndView saveEmployee(#Valid #ModelAttribute("employee") EmployeeDTO employee, BindingResult bindingResult, final HttpServletRequest request, final Model model) {
ModelAndView mav = new ModelAndView();
//Create a new BindingResult with zero errors
BindingResult newBindingResult = new BeanPropertyBindingResult(employee, "employee");
//Add to the new BindingResult the error which is caused by the field 'employeeNumber'
newBindingResult.addError(bindingResult.getFieldError("employeeNumber"));
//If required, more fields can be added to the new BindingResult
//Check if the new BindingResult contains errors -> only the fields added above.
if (newBindingResult.hasErrors()) {
//Do this, if the new BindingResult contains validation errors
} else {
//Do that, if the new BindingResult does not contain errors validation errors
//If your form contains other validation errors for fields other than 'employeeNumber', the validation for them will be ignored.
}
//Set the view and return it.
mav.setViewName(xxx);
return mav;
}