private final AuthenticationManager authenticationManager;
    private final PropertyFileText properties;

    public JWTAuthenticationFilter(AuthenticationManager authenticationManager) {
        this.authenticationManager = authenticationManager;
        properties = new PropertyFileText(this.getClass().getResource("/security.properties").getPath());
        setUsernameParameter("email");
    }

    @Override
    public Authentication attemptAuthentication(HttpServletRequest httpServletRequest,
                                                HttpServletResponse httpServletResponse)
            throws AuthenticationException {
        try {
            ObjectMapper objectMapper = new ObjectMapper();
            AuthenticationCredentials credentials = objectMapper.readValue(httpServletRequest.getInputStream(),
                    AuthenticationCredentials.class);

            return authenticationManager.authenticate(
                    new UsernamePasswordAuthenticationToken(
                        credentials.getEmail(),
                        credentials.getPassword(), emptyList()
                    )
            );
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @Override
    protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult) throws IOException, ServletException {
        long expirationTime = Long.valueOf(properties.read("EXPIRATION_TIME"));
        String secretKey = properties.read("SECRET");
        String headerString = properties.read("HEADER_STRING");
        String tokenPrefix = properties.read("TOKEN_PREFIX");

        String token = Jwts.builder()
                .setSubject(((User) authResult.getPrincipal()).getUsername())
                .setExpiration(new Date(System.currentTimeMillis() + expirationTime))
                .signWith(SignatureAlgorithm.HS512, secretKey)
                .compact();

        response.addHeader(headerString, tokenPrefix + token);
    }