SpringBoot 拦截器

登录成功后将用户存入session

    @ResponseBody
    @PostMapping("/login")
    public String login(User user, HttpServletRequest request) {
        HttpSession session = request.getSession();
        if(user.getUsername().equals("bob") && user.getPassword().equals("123")) {
            session.setAttribute("user",user);
            return "登录成功";
        } else {
            return "登录失败";
        }
    }

检查session中用户是否为空，不为空放行，为空跳转到登录界面

public class LoginInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String requestURI = request.getRequestURI();
        System.out.println("请求的路径为：" + requestURI);
        HttpSession session = request.getSession();
        Object user = session.getAttribute("user");
        if(user != null) {
            return true;
        }
        request.setAttribute("msg","请先登录~");
        request.getRequestDispatcher("/").forward(request, response);
        return false;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}

注：服务器内部转发也会经过拦截器

@Configuration
public class AdminMvcConfiguration implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoginInterceptor())
                .addPathPatterns("
                .excludePathPatterns("/","/login","/res/**");
    }
}