SpringBoot框架Day04之拦截器

SpringBoot拦截器

1. 编写一个拦截器实现类实现HandlerInterceptor接口

/**
 * 登录检查
 * 1.配置拦截请求
 * 2.把配置放在容器中
 */
@Slf4j
public class LoginInterceptor implements HandlerInterceptor {
    
    
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    
    
        log.info("preHandle()拦截的请求路径为:"+request.getRequestURI());
        HttpSession session = request.getSession();
        Object loginUser = session.getAttribute("loginUser");
        if (loginUser != null) {
    
    
            System.out.println("登录检查1s后必放行");
            return true; // 放行
        }
        System.out.println("登录检查拦截器正在拦截ing...并自动跳转到登录页面");
        request.setAttribute("msg","拦截器告诉你，请先登录");
        request.getRequestDispatcher("/").forward(request, response);

        return false; // 否则拦截住
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    
    
        log.info("postHandle执行的modelAndView对象"+modelAndView);
    }

    /**
     * 页面渲染之后
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    
    
        log.info("afterCompletion执行结束旗下是否有异常"+ex);
    }
}

2. 拦截器注册到容器中。实现WebMvcConfigurer接口中的addInterceptors()方法的addInterceptor()方法。
3. 链式调用指定拦截规则

@Configuration
public class AdminWebConfig implements WebMvcConfigurer {
    
    
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
    
    
        // 杠双星/**默认拦截所有资源（包括静态资源css,js）
        registry.addInterceptor(new LoginInterceptor())
                .addPathPatterns("/**")
                .excludePathPatterns("/","/login","/css/**","/fonts/**","/images/**","/js/**"); // 放行的请求
    }
}