JwtAuthenticationFilter.java

package fr.tiogars.domaintemplate.domains.auth.services;

import java.io.IOException;

import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;

import jakarta.servlet.FilterChain;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

/** Reads Bearer tokens and populates the Spring Security context. */
@Component
public class JwtAuthenticationFilter extends OncePerRequestFilter {

    private final JwtTokenService jwtTokenService;
    private final UserDetailsService userDetailsService;

    JwtAuthenticationFilter(JwtTokenService jwtTokenService, UserDetailsService userDetailsService) {
        this.jwtTokenService = jwtTokenService;
        this.userDetailsService = userDetailsService;
    }

    @Override
    protected void doFilterInternal(
            HttpServletRequest request,
            HttpServletResponse response,
            FilterChain filterChain)
            throws ServletException, IOException {
        String authorization = request.getHeader("Authorization");
        if (authorization != null
                && authorization.startsWith("Bearer ")
                && SecurityContextHolder.getContext().getAuthentication() == null) {
            String token = authorization.substring(7);
            String username = jwtTokenService.extractUsername(token).orElse(null);
            if (username != null) {
                UserDetails userDetails = userDetailsService.loadUserByUsername(username);
                if (jwtTokenService.isValid(token, userDetails)) {
                    UsernamePasswordAuthenticationToken authentication = new UsernamePasswordAuthenticationToken(
                            userDetails,
                            null,
                            userDetails.getAuthorities());
                    authentication.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
                    SecurityContextHolder.getContext().setAuthentication(authentication);
                }
            }
        }
        filterChain.doFilter(request, response);
    }
}