JwtAuthenticationFilter.java

package com.ctrlbuy.webshop.security.filter;

import com.ctrlbuy.webshop.security.JwtService;
import jakarta.servlet.FilterChain;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
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;
import java.util.Arrays;
import java.util.List;
import java.util.Optional;

@Component
public class JwtAuthenticationFilter extends OncePerRequestFilter {

    private final JwtService jwtService;
    private final UserDetailsService userDetailsService;

    // Lista över URL:er som inte kräver autentisering
    private final List<String> publicUrls = Arrays.asList(
            "/", "/home", "/welcome", "/about", "/contact", "/products",
            "/login", "/login-process", "/logout-process", "/register",
            "/static", "/css", "/js", "/images",
            "/api/auth", "/api/register"
    );

    public JwtAuthenticationFilter(@NonNull JwtService jwtService, @NonNull UserDetailsService userDetailsService) {
        this.jwtService = jwtService;
        this.userDetailsService = userDetailsService;
    }

    @Override
    protected boolean shouldNotFilter(HttpServletRequest request) {
        String path = request.getRequestURI();
        return publicUrls.stream().anyMatch(path::startsWith);
    }

    @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);
        Optional<String> usernameOptional = jwtService.extractUsername(jwt);

        if (usernameOptional.isEmpty()) {
            response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Invalid token.");
            return;
        }

        String username = usernameOptional.get();

        if (SecurityContextHolder.getContext().getAuthentication() == null) {
            UserDetails userDetails = userDetailsService.loadUserByUsername(username);

            if (jwtService.isTokenValid(jwt, username)) {
                UsernamePasswordAuthenticationToken authToken = new UsernamePasswordAuthenticationToken(
                        userDetails, null, userDetails.getAuthorities());
                authToken.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));

                SecurityContextHolder.getContext().setAuthentication(authToken);
            } else {
                response.sendError(HttpServletResponse.SC_UNAUTHORIZED, "Invalid token.");
                return;
            }
        }

        filterChain.doFilter(request, response);
    }
}