@Slf4j
@WebFilter(urlPatterns = "/*") //拦截所有请求
public class LoginCheckFilter implements Filter {@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException {//前置：强制转换为http协议的请求对象、响应对象 （转换原因：要使用子类中特有方法）HttpServletRequest request = (HttpServletRequest) servletRequest;HttpServletResponse response = (HttpServletResponse) servletResponse;//1.获取请求urlString url = request.getRequestURL().toString();log.info("请求路径：{}", url); //请求路径：http://localhost:8080/login//2.判断请求url中是否包含login，如果包含，说明是登录操作，放行if(url.contains("/login")){chain.doFilter(request, response);//放行请求return;//结束当前方法的执行}//3.获取请求头中的令牌（token）String token = request.getHeader("token");log.info("从请求头中获取的令牌：{}",token);//4.判断令牌是否存在，如果不存在，返回错误结果（未登录）if(!StringUtils.hasLength(token)){log.info("Token不存在");Result responseResult = Result.error("NOT_LOGIN");//把Result对象转换为JSON格式字符串 (fastjson是阿里巴巴提供的用于实现对象和json的转换工具类)String json = JSONObject.toJSONString(responseResult);response.setContentType("application/json;charset=utf-8");//响应response.getWriter().write(json);return;}//5.解析token，如果解析失败，返回错误结果（未登录）try {JwtUtils.parseJWT(token);}catch (Exception e){log.info("令牌解析失败!");Result responseResult = Result.error("NOT_LOGIN");//把Result对象转换为JSON格式字符串 (fastjson是阿里巴巴提供的用于实现对象和json的转换工具类)String json = JSONObject.toJSONString(responseResult);response.setContentType("application/json;charset=utf-8");//响应response.getWriter().write(json);return;}//6.放行chain.doFilter(request, response);}
}
