当认证失败的时候会进入AuthenticationEntryPoint，于是我们自定义认证失败返回的数据：

/**
 * 定义认证失败处理类
 */
@Slf4j
@Component
public class JwtAuthenticationEntryPoint implements AuthenticationEntryPoint {
   @Override
   public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException authException)
         throws IOException {
      log.info("认证失败！未登录！");
      response.setContentType("application/json;charset=UTF-8");
      response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
      ServletOutputStream outputStream = response.getOutputStream();

      Result result = Result.fail("请先登录！");
      outputStream.write(JSONUtil.toJsonStr(result).getBytes("UTF-8"));
      outputStream.flush();
      outputStream.close();
   }
}

不过是啥原因，认证失败，我们就要求重新登录，所以返回的信息直接明了“请先登录！”哈哈。