Add custom claim in authentication filter. Get user id in filter. Spring boot - spring

Question

I want to add user's id as custom claim into my token.
But i cant get users id in filter because dependency injection isnt working in filters. I tried using constructor of my UserService but in this service i have repository which im #Autowiring so in debug mode i have seen that userRepository field is null.
My question is how i will add this custom claim?
Maybe is it another way to add this.
I was following this tutorial (without "Aside" chapter)
https://auth0.com/blog/implementing-jwt-authentication-on-spring-boot/#User-Authentication-and-Authorization-on-Spring-Boot
this is my filter where im trying to add this claim
package com.kamczi.auth;
import com.auth0.jwt.JWT;
import static com.auth0.jwt.algorithms.Algorithm.HMAC512;
import com.fasterxml.jackson.databind.ObjectMapper;
import static com.kamczi.auth.SecurityConstants.EXPIRATION_TIME;
import static com.kamczi.auth.SecurityConstants.HEADER_STRING;
import static com.kamczi.auth.SecurityConstants.SECRET;
import static com.kamczi.auth.SecurityConstants.TOKEN_PREFIX;
import com.kamczi.entities.User;
import com.kamczi.repository.UserRepository;
import com.kamczi.services.UserService;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
/**
*
* #author Kamil
*/
public class JWTAuthenticationFilter extends UsernamePasswordAuthenticationFilter {
private AuthenticationManager authenticationManager;
public JWTAuthenticationFilter(AuthenticationManager authenticationManager) {
this.authenticationManager = authenticationManager;
}
#Override
public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {
try{
User user = new ObjectMapper()
.readValue(request.getInputStream(), User.class);
return authenticationManager.authenticate(
new UsernamePasswordAuthenticationToken(
user.getUsername(),
user.getPassword(),
new ArrayList<>())
);
} catch(IOException e){
throw new RuntimeException(e);
}
}
#Override
protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult) throws IOException, ServletException {
String username = ((org.springframework.security.core.userdetails.User) authResult.getPrincipal()).getUsername();
String token = JWT.create()
//.withClaim("id", userService.findByUsername(username).getUser_id()) need implementation
.withSubject(username)
.withExpiresAt(new Date(System.currentTimeMillis()+EXPIRATION_TIME))
.sign(HMAC512(SECRET.getBytes()));
response.addHeader(HEADER_STRING, TOKEN_PREFIX + token);
}
}

Answer 1

Try to mark your filter with #Component. The #Autowired is working only with Spring-managed beans (components).
Or you can add the filter manually using the constructor and pass the repository to it.
#Configuration
public class SecurityConfiguration extends WebSecurityConfigurerAdapter {
#Autowired
UsersRepository usersRepo;
#Override
protected void configure(HttpSecurity http) throws Exception {
http.addFilterAt(new JWTAuthenticationFilter(usersRepo), UsernamePasswordAuthenticationFilter.class);
}
}