JwtAuthFilter.java

package com.wavii.config;

import com.wavii.config.CustomUserDetailsService;
import com.wavii.service.JwtService;
import jakarta.servlet.FilterChain;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.lang.NonNull;
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 java.io.IOException;

/**
 * Filtro de seguridad para la autenticación mediante tokens JWT.
 * Intercepta cada petición para validar el token Bearer en el header de Authorization.
 * 
 * @author eduglezexp
 */
@Component
@RequiredArgsConstructor
@Slf4j
public class JwtAuthFilter extends OncePerRequestFilter {

    private final JwtService jwtService;
    private final CustomUserDetailsService customUserDetailsService;

    @Override
    protected void doFilterInternal(
            @NonNull HttpServletRequest request,
            @NonNull HttpServletResponse response,
            @NonNull FilterChain filterChain
    ) throws ServletException, IOException {

        final String authHeader = request.getHeader("Authorization");

        if (authHeader == null || !authHeader.startsWith("Bearer ")) {
            filterChain.doFilter(request, response);
            return;
        }

        final String jwt = authHeader.substring(7);

        try {
            final String email = jwtService.extractEmail(jwt);

            if (email != null && SecurityContextHolder.getContext().getAuthentication() == null) {
                UserDetails userDetails = customUserDetailsService.loadUserByUsername(email);

                if (jwtService.isTokenValid(jwt, (com.wavii.model.User) userDetails)) {
                    UsernamePasswordAuthenticationToken authToken =
                            new UsernamePasswordAuthenticationToken(
                                    userDetails,
                                    null,
                                    userDetails.getAuthorities()
                            );
                    authToken.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
                    SecurityContextHolder.getContext().setAuthentication(authToken);
                }
            }
        } catch (Exception e) {
            log.debug("JWT inválido: {}", e.getMessage());
        }

        filterChain.doFilter(request, response);
    }
}