springboot 登錄攔截器

1.定義一個視圖解析器

@Configuration
public class MyMvcConfig implements WebMvcConfigurer {
    /**
     * 添加視圖解析
     */
    //// 無用代碼，暫時注釋，之后刪除
//    @Override
//    public void addViewControllers(ViewControllerRegistry registry) {
//        registry.addViewController("/").setViewName("index");
//        registry.addViewController("/index.html").setViewName("index");
//        registry.addViewController("/login.html").setViewName("login");
//        registry.addViewController("/login").setViewName("login");
//        registry.addViewController("/personal_center").setViewName("personal_center");
//    }

    /**
     * 注冊攔截器
     */
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
//        registry.addInterceptor(new LoginInterceptor())
//                .addPathPatterns("/**").excludePathPatterns("/index","/","/login","/user/login","/static/**","/druid/*");
        InterceptorRegistration addInterceptor = registry.addInterceptor(new LoginInterceptor());
        // 排除配置
        addInterceptor.excludePathPatterns("/index");
        addInterceptor.excludePathPatterns("/login");
        addInterceptor.excludePathPatterns("/");
        addInterceptor.excludePathPatterns("/error");
        addInterceptor.excludePathPatterns("/static/**");
        addInterceptor.excludePathPatterns("/pdb/tuba/**");
        addInterceptor.excludePathPatterns("/test/**");
        // 攔截配置
        addInterceptor.addPathPatterns("/**");
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");
    }
}

2.定義一個攔截器

/**
 * 登錄攔截器
 */
public class LoginInterceptor implements HandlerInterceptor {

    /**
     * 在請求處理之前進行調用（Controller方法調用之前）
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
                             Object object) throws ServletException, IOException {
        Object user = request.getSession().getAttribute("user");
        if (user==null){
            request.setAttribute("error","當前處於未登錄狀態!");
//            request.getRequestDispatcher("/").forward(request,response);
            response.sendRedirect("/index");
            return false;
        }else {
            return true;
        }
    }

    /**
     * 請求處理之后進行調用，但是在視圖被渲染之前（Controller方法調用之后）
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response,
                           Object object, ModelAndView mv)
            throws Exception {
        // TODO Auto-generated method stub
    }

    /**
     * 在整個請求結束之后被調用，也就是在DispatcherServlet 渲染了對應的視圖之后執行
     * （主要是用於進行資源清理工作）
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response,
                                Object object, Exception ex)
            throws Exception {
        // TODO Auto-generated method stub
    }
}