wordpress实现支付,重庆快速排名优化,大牌装修公司,如何登陆工商局网站做变更学习目标#xff1a;
提示#xff1a;学习如何利用Redis实现添加缓存功能解决缓存穿透版 学习产出#xff1a;
缓存穿透讲解图#xff1a; 解决方案#xff1a;
采用缓存空对象采用布隆过滤器 解决方案流程图#xff1a;
1. 准备pom环境 dependencygro…学习目标
提示学习如何利用Redis实现添加缓存功能解决缓存穿透版 学习产出
缓存穿透讲解图 解决方案
采用缓存空对象采用布隆过滤器 解决方案流程图
1. 准备pom环境 dependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-data-redis/artifactId/dependencydependencygroupIdorg.apache.commons/groupIdartifactIdcommons-pool2/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-web/artifactId/dependencydependencygroupIdmysql/groupIdartifactIdmysql-connector-java/artifactIdscoperuntime/scopeversion5.1.47/version/dependencydependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdoptionaltrue/optional/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-test/artifactIdscopetest/scope/dependencydependencygroupIdcom.baomidou/groupIdartifactIdmybatis-plus-boot-starter/artifactIdversion3.4.3/version/dependency!--hutool--dependencygroupIdcn.hutool/groupIdartifactIdhutool-all/artifactIdversion5.7.17/version/dependency2. 配置ThreadLocal和过滤器
public class UserHolder {private static final ThreadLocalUserDTO tl new ThreadLocal();public static void saveUser(UserDTO user){tl.set(user);}public static UserDTO getUser(){return tl.get();}public static void removeUser(){tl.remove();}
}Configuration
public class MvcConfig implements WebMvcConfigurer {Autowiredprivate StringRedisTemplate redis;Overridepublic void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(new LoginInterceptor()).excludePathPatterns(/user/code,/user/login,/blog/hot,/shop/**,/shop-type/**,/voucher/**).order(2);registry.addInterceptor(new RefreshTokenInterceptor(redis)).addPathPatterns(/**).order(1);}
}
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Slf4j
public class LoginInterceptor implements HandlerInterceptor {//controller执行之前Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {//1.判断是否需要拦截ThreadLocalif (UserHolder.getUser()null) {response.setStatus(401);return false;}//7.放行return true;}//渲染后返回给前台数据前Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {//移除用户避免内存泄露UserHolder.removeUser();}
}
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Slf4j
public class RefreshTokenInterceptor implements HandlerInterceptor {//这个对象不是由spring管理的所以不能用注解自动注入private StringRedisTemplate redis;public RefreshTokenInterceptor(StringRedisTemplate redis) {this.redis redis;}//controller执行之前Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {//1.获取请求头中的tokenString token request.getHeader(authorization);if (StrUtil.isBlank(token)) {return true;}//2.基于token获取redis中的用户//通过key取到hash中的map集合数据MapObject, Object userMap redis.opsForHash().entries(login:token: token);//3.判断用户是否存在if (userMap.isEmpty()) {return true;}//5.将查询到的hash数据转为userDto对象UserDTO userDTO BeanUtil.fillBeanWithMap(userMap, new UserDTO(), false);//6.存在保存用户信息到ThreadLocal中UserHolder.saveUser(userDTO);//7.刷新token有效期redis.expire(LOGIN_USER_KEY token, 30, TimeUnit.MINUTES);log.info(我是第一个拦截器当前拦截所有请求的用户为线程为{},{},UserHolder.getUser(),Thread.currentThread());//8.放行return true;}3. Controller层负责接收请求和向下分配
RestController
RequestMapping(/shop)
public class ShopController {Resourcepublic IShopService shopService;/*** 根据id查询商铺信息* param id 商铺id* return 商铺详情数据*/GetMapping(/{id})public Result queryShopById(PathVariable(id) Long id) {return Result.ok(shopService.queryShopById(id));}
}4. Service层负责业务的处理逻辑
Service
Slf4j
public class ShopServiceImpl extends ServiceImplShopMapper, Shop implements IShopService {Resourceprivate StringRedisTemplate redis;public Result queryShopById(Long id) {//1.从Redis查询数据缓存String shopCache redis.opsForValue().get(cache:shop: id);//2.判断是否存在 当shopCache为“”时返回falseif (StrUtil.isNotBlank(shopCache)) {//3.存在直接返回Shop shop JSONUtil.toBean(shopCache, Shop.class);return Result.ok(shop);}//判断命中的是否是空值if (shopCache!null) {return Result.fail( 店铺信息不存在 );}//4.不存在根据id查询数据库Shop shop getById(id);if (ObjectUtil.isEmpty(shop)) {// 解决缓存穿透redis.opsForValue().set(cache:shop: id,,2,TimeUnit.MINUTES);//5.不存在返回错误return Result.fail(当前商户不存在);}//6.存在写入redisredis.opsForValue().set(cache:shop:id,JSONUtil.toJsonStr(shop));redis.expire(cache:shop:id,30,TimeUnit.MINUTES);//7.返回return Result.ok(shop);}
}
