content: package com.example.demo.security.provider;
  
  import com.example.demo.dto.AccountDTO;
  import com.example.demo.security.jwt.JwtDecoder;
  import com.example.demo.security.token.JwtPreProcessingToken;
  import com.example.demo.security.token.PostAuthorizationToken;
  import lombok.RequiredArgsConstructor;
  import org.springframework.security.authentication.AuthenticationProvider;
  import org.springframework.security.core.Authentication;
  import org.springframework.security.core.AuthenticationException;
  import org.springframework.stereotype.Component;
  
  @Component
  @RequiredArgsConstructor
  public class JWTAuthenticationProvider implements AuthenticationProvider {
  
      private final JwtDecoder jwtDecoder;
  
      @Override
      public Authentication authenticate(Authentication authentication)
              throws AuthenticationException {
          String     token      = (String) authentication.getPrincipal();
          AccountDTO accountDTO = jwtDecoder.decodeJwt(token);
  
          return PostAuthorizationToken.getTokenFormUserDetails(accountDTO);
      }
  
      @Override
      public boolean supports(Class<?> authentication) {
          return JwtPreProcessingToken.class.isAssignableFrom(authentication);
      }
  }