实现目标：

展示用户的搜索记录10条，按照搜索关键词的时间倒序
可以删除搜索记录
保存历史记录，保存10条，多余的则删除最久的历史记录

数据库的选择：

用户的搜索记录，需要给每一个用户都保存一份，数据量较大，要求加载速度快，通常这样的数据存储到mongodb更合适，不建议直接存储到关系型数据库中。与redis对比，MongoDB是结构化数据，而redis中只有keyValue。

实现思路：

实现

保存

1. 创建实体类

```java @Data @Document("apusersearch") // mongoDB的映射注解 public class ApUserSearch implements Serializable { private static final long serialVersionUID = 1L;

private Integer userId; private String keyword; private Date createdTime; } ```

2. 保存userSearch

```java @Autowired private MongoTemplate mongoTemplate;

// keyword从dto中获取，userId从线程中获取 @Override public void insert(String keyword, Integer userId){ // 1. 查询当前用户的搜索关键词 Query query = Query.query(Criteria .where("userId").is(userId) .and("keyword").is(keyword)); ApUserSearch apUserSearch = ApUsermongoTemplate.findOne(query, ApUserSearch.class); // 2. 存在，更新创建时间 if(apUserSearch != null) { apUserSerach.setCreatedTime(new Date()); mongoTemplate.save(apUserSearch); return; } // 3. 不存在，判断当前历史总是是否超过10 apUserSearch = new ApUserSearch(); apUserSearch.setUserId(userId); apUserSearch.setKeyWord(keyword); apUserSearch.setCreatedTime(new Date())； // 重新排序 Query query1 = Query.query(Criteria .where("userId").is(userId); query1.with(Sort.by(Sort.Direction.DESC, "createdTime")); List list = mongoTemplate.find(query1, ApUserSearch.class); // 保存历史记录，保存10条，多余的则删除最久的历史记录 if(list == null || list.size() < 10){ mongoTemplate.save(apUserSearch); }else{ ApUserSearch lastInfo = apUserSearchList.get(apUserSearchList.size() - 1); // 替换 mongoTemplate.findAndReplace( Query.query(Criteria.where("id").is(lastInfo.getId()) , apUserSearch); }

} ```

3. 获取当前的用户

拦截器类，继承Ordered,GlobalFilter,其中重写filter方法,获取到了用户信息，存储到了header中，再重置请求

java @Override public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) { //1.获取request和response对象 ServerHttpRequest request = exchange.getRequest(); ServerHttpResponse response = exchange.getResponse(); }

实现一个工具类AppThreadLocalUtil在utils的Service服务中，用于获取用户 ```java public class AppThreadLocalUtil {

private final static ThreadLocal<ApUser> WM_USER_THREAD_LOCAL = new ThreadLocal<>();//存入线程中
public static void setUser(ApUser apUser){WM_USER_THREAD_LOCAL.set(apUser);
}//从线程中获取
public static ApUser getUser(){return WM_USER_THREAD_LOCAL.get();
}//清理
public static void clear(){WM_USER_THREAD_LOCAL.remove();
}

} ``` 实现拦截器

```java public class AppTokenInterceptor implements HandlerInterceptor { // 把用户解析放在线程中 @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { String userId = request.getHeader("userId"); if(userId != null){ //存入到当前线程中 ApUser apUser = new ApUser(); apUser.setId(Integer.valueOf(userId)); AppThreadLocalUtil.setUser(apUser);

}return true;
}
// 清理线程
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {AppThreadLocalUtil.clear();
}

} ``` 在config中的WebMvcConfig中配置

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

4. 最后在ArticleSerachServiceImple中的search函数中添加

java ApUser user = AppThreadLocalUtil.getUser(); if(user != null && dto.getFromIndex() == 0){ // 首页 // 异步调用保存搜索记录 apUserSearchService.insert(dto.getSearchWords(), user.getId()); }

查询

java List<ApUserSearch> apUserSearches = mongoTemplate.find(Query.query(Criteria.where("userId").is(user.getId())).with(Sort.by(Sort.Direction.DESC, "createdTime")), ApUserSearch.class);

删除

```java //1.检查参数 if(dto.getId() == null){ return ResponseResult.errorResult(AppHttpCodeEnum.PARAM_INVALID); }

//2.判断是否登录 ApUser user = AppThreadLocalUtil.getUser(); if(user == null){ return ResponseResult.errorResult(AppHttpCodeEnum.NEED_LOGIN); }

//3.删除 mongoTemplate.remove(Query.query(Criteria.where("userId").is(user.getId()).and("id").is(dto.getId())),ApUserSearch.class); return ResponseResult.okResult(AppHttpCodeEnum.SUCCESS); ```