private String getMessage(AuthenticationException failed) {
        String message = "Server Error";
        if (failed instanceof UsernameNotFoundException) {
            message = "用户不存在";
        } else if (failed instanceof BadCredentialsException) {
            message = "密码错误";
        }
        return message;
    }
@Test
    public void getMessageTest() {
        JWTAuthenticationFilter filter = new JWTAuthenticationFilter(null);
        Assertions.assertEquals("用户不存在", ReflectUtil.invoke(filter,
                "getMessage", new UsernameNotFoundException("")));
        Assertions.assertEquals("密码错误", ReflectUtil.invoke(filter,
                "getMessage", new BadCredentialsException("")));
    }