Springboot拦截器的使用

小咪咪 2023-01-15 08:29 145阅读 0赞

## 1.创建拦截器 ##

1.  实现HandlerInterceptor 接口
2.  重写preHandle方法

@Component
    public class CartInterceptor implements HandlerInterceptor { 
    
        public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();
        /** * 在目标方法执行之前拦截 * * @param request * @param response * @param handler * @return * @throws Exception */
        @Override
        public boolean preHandle(HttpServletRequest request,
                                 HttpServletResponse response,
                                 Object handler) throws Exception { 
            UserInfoTo userInfoTo = new UserInfoTo();
    
            HttpSession session = request.getSession();
            MemberRespVo member = (MemberRespVo) session.getAttribute(AuthServerConstant.LOGIN_USER);
            if (member != null) { 
                //用户登录
                userInfoTo.setUserId(member.getId());
    
            }
            //思考：什么时候存了cookies?
            Cookie[] cookies = request.getCookies();
            if (cookies != null && cookies.length > 0) { 
                for (Cookie cookie : cookies) { 
                    String name = cookie.getName();
                    if (name.equals(CartConstant.TEMP_USER_COOKIE_NAME)) { 
                        userInfoTo.setUserKey(cookie.getValue());
                    }
                }
            }
            //目标方法执行之前
            threadLocal.set(userInfoTo);
            return true;
        }
    }

## 2.配置拦截哪些请求 ##

1.  实现WebMvcConfigurer 接口
2.  重写addInterceptors方法

@Configuration
    public class MallWebConfig implements WebMvcConfigurer { 
        @Override
        public void addInterceptors(InterceptorRegistry registry) { 
            registry.addInterceptor(new CartInterceptor()).addPathPatterns("/**");
        }
    }