JWT Decoder for Spring Boot Developers

// JWT authentication in Spring Boot
import io.jsonwebtoken.Jwts;

@Component
public class JwtFilter extends OncePerRequestFilter {
    @Override
    protected void doFilterInternal(HttpServletRequest request,
            HttpServletResponse response, FilterChain chain)
            throws ServletException, IOException {
        String token = request.getHeader("Authorization").substring(7);
        var claims = Jwts.parserBuilder()
            .setSigningKey(secretKey)
            .build()
            .parseClaimsJws(token)
            .getBody();
        // Set authentication context...
        chain.doFilter(request, response);
    }
}