实战编写高内聚低耦合的代码
故事是这样的,就是作品点赞数,评论数,转发量 缓存同步数据数量
原来队友没有同步数据库,导致排序不生效,现在要我处理
思路1
- 直接在他们调用的地方 在集成数据库同步的代码,简单 代码越来越耦合 ,臃肿不堪 ,每个地方集成
思路2
- 利用spring 事件机制,没个集成的地方,发布事件,观察者模式其实就是
思路3
- 提供上下文操作发布事件方法,内聚起来,其他地方用 只需要 持有上下文对象就行,不需要每个地方再去 发布事件
代码演示
- 内聚 调用方法
@Component
public class WorkEventContext {
@Autowired
private ApplicationContext applicationContext;
/**
* 作品 点赞事件
* @param worksId
* @param count
*/
public void publishLikeEvent(Long worksId,Integer count){
WorkLikeEvent workLikeEvent = new WorkLikeEvent();
workLikeEvent.setWorkId(worksId);
workLikeEvent.setLikeCount(count);
applicationContext.publishEvent(workLikeEvent);
}
/**
* 发布一个评论 事件
* @param workId
* @param count
*/
public void publishDiscussEvent(Long workId,Integer count){
WorkDiscussEvent workDiscussEvent = new WorkDiscussEvent();
workDiscussEvent.setWorkId(workId);
workDiscussEvent.setDiscussCount(count);
applicationContext.publishEvent(workDiscussEvent);
}
/**
* 作品转发 事件
* @param workId
* @param count
*/
public void publishForwardEvent(Long workId,Integer count){
WorkForwardEvent workForwardEvent = new WorkForwardEvent();
workForwardEvent.setWorkId(workId);
workForwardEvent.setForwardCount(count);
applicationContext.publishEvent(workForwardEvent);
}
}
- 解耦 观察者
@Component
@Slf4j
public class WorkListener {
@Autowired
private WorksService worksService;
/**
* 点赞
* @param event
*/
@EventListener
public void handleWorkLikeEvent(WorkLikeEvent event) {
Long workId = event.getWorkId();
Integer likeCount = event.getLikeCount();
log.info("作品id:{},作品点赞数:{}",workId,likeCount);
Works works = new Works();
works.setId(workId);
works.setLikeCount(likeCount);
worksService.updateById(works);
}
/**
* 评论
* @param event
*/
@EventListener
public void handleWorkDiscussEvent(WorkDiscussEvent event) {
Long workId = event.getWorkId();
Integer discussCount = event.getDiscussCount();
log.info("作品id:{},作品评论数:{}",workId,discussCount);
Works works = new Works();
works.setId(workId);
works.setDiscussCount(discussCount);
worksService.updateById(works);
}
/**
* 转发
* @param event
*/
@EventListener
public void handleWorkForwardEvent(WorkForwardEvent event) {
Long workId = event.getWorkId();
Integer forwardCount = event.getForwardCount();
log.info("作品id:{},作品转发数:{}",workId,forwardCount);
Works works = new Works();
works.setId(workId);
works.setForwardCount(forwardCount);
worksService.updateById(works);
}
}
- 使用
elk