登录 jwt ,filter

cookie 在请求头中叫做cookie，在响应头中叫set-cookie

 @GetMapping("/c1")
    public Result cookie1(HttpServletResponse resp){
        resp.addCookie(new Cookie("login_name","itheima"));
        return Result.success();
    }
    @GetMapping("/c2")
    public Result cookie2(HttpServletRequest request){
        Cookie [] cookies = request.getCookies();
        for(Cookie cookie : cookies){
            if(cookie.getName().equals("login_username")){
                System.out.println("login_username" + cookie.getValue());
            }
        }
        return Result.success();
    }

当前所在位置和请求位置，然后从3维度来判断是否是跨哉请求，只要有一个不同就属于

session基于cookie实现

java 复制代码

@GetMapping("/s1")
    public Result session1(HttpSession session){
        session.setAttribute("loginUser", "tom");
        return Result.success();
    }

    @GetMapping("/s2")
    public Result session2(HttpServletRequest request){
        HttpSession session = request.getSession();
        Object loginUser = session.getAttribute("loginUser");
        return Result.success(loginUser);
    }

拦截器

Filter

java 复制代码

@Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest req = (HttpServletRequest) servletRequest;
        HttpServletResponse resp = (HttpServletResponse)servletResponse;
        //获取请求的url
        String url = req.getRequestURL().toString();
        //判断是否包含登录
        if(url.contains("login")){
            filterChain.doFilter(req, resp);
            return;
        }
        //获取请求头中的令牌
        String jwt = req.getHeader("token");
        if(!StringUtils.hasLength(jwt)){ //如果为空
            Result errorRet = Result.error("NOT_LOGIN");
            //阿里巴巴fastJson
            String notLogin = JSONObject.toJSONString(errorRet);
            //将json字符串返回给浏览器
            resp.getWriter().write(notLogin);
        }
        //解析token，如果解析失败，返回错误结果
        try {
            JwtUtils.parseJwt(jwt);
        } catch(Exception e){
            Result errorRet = Result.error("NOT_LOGIN");
            //阿里巴巴fastJson
            String notLogin = JSONObject.toJSONString(errorRet);
            //将json字符串返回给浏览器
            resp.getWriter().write(notLogin);
            return;
        }
        //放行
        filterChain.doFilter(req, resp);
    }