why am I getting Null Pointer Exception while trying to check if the username is already present in the database?

Question

This code is to check if the user is already registered to the application or not ,and I am getting null pointer exception while checking if the similar username exists in the database

@ResponseStatus(HttpStatus.CREATED)
@PostMapping("/register")
public String registeruser(HttpServletRequest request, @RequestBody UserDetails requestData) {
String userName = requestData.getUsername();
        System.out.println("checking user");
        System.out.println(userName);
        System.out.println(uDao.existsById(userName));// I AM GETTING ERROR HERE
if ((uDao.existsById(userName))) {
            throw new UserAlreadyExistException("You have already registered. please log in");
        }
String userRole = (String) request.getSession().getAttribute("role");
if (!userRole.equalsIgnoreCase("productmaster") || !userRole.equalsIgnoreCase("admin")||!userRole.equalsIgnoreCase("Retailer")) {
throw new InvalidUserRoleException("you are not authorized to add the products");
}
@SuppressWarnings("unused")
boolean newuser = true;
UserDetails user = new UserDetails(requestData.getUsername(), requestData.getPassword()),requestData.getUserRole());
if (newuser = uservice.add(user)) {
return "User successfully added";
}
return "User is not added";
}

score 0 · Accepted Answer · answered Nov 19 '22 at 19:27

0

Either the uDao or userName is null. The parameter of existsById must not be null. Check out the documentation here.

answered Nov 19 '22 at 19:27

gkatiforis

1,588
9
19

as you can see, I printed out the username to see if its null but no its printing the username how do I check if existbyid is null ? – error_09 Nov 20 '22 at 08:25
then the dao object "uDao" shoud be null – gkatiforis Nov 20 '22 at 14:17

why am I getting Null Pointer Exception while trying to check if the username is already present in the database?

1 Answers1