总结 redis缓存在增删改中的应用示例

add：添加成功，清理缓存；

update：修改成功，清理缓存；

del：删除成功，清理缓存；

get：查询列表，先从缓存中取数据，缓存中数据为空再从数据库读取数据；
适用范围，数据量小且不经常变动的数据，利用缓存读写分离，减轻数据库压力，提高效率

/**
 * 自定义应用dao层实现层
 */
@Repository("iApplicationCustomizeDao")
public class ApplicationCustomizeDaoImpl extends BaseDaoMybatis implements IApplicationCustomizeDao {

    @Override
    public ApplicationCustomize add(ApplicationCustomize app) throws Exception {
        RedisClient redisClient = new RedisClient(CacheKey.PREFIX_APPLICATION_CUSTOMIZE);
        app.setId(ConfigUtil.getSeqNo());
        app.setType(1);
        app.setSupportAndroid(0);
        app.setSupportWeb(0);
        app.setSupportIos(0);
        log.debug("新增应用，app={}", app);
        if(this.insert("APP_CUSTOMIZE.add", app) > 0){
            // 清理对应缓存
            redisClient.deleteObject(app.getCompanyId());
            return app;
        }
        return null;
    }

    @Override
    public int removeById(String companyId, String appId) {
        RedisClient redisClient = new RedisClient(CacheKey.PREFIX_APPLICATION_CUSTOMIZE);
        if(this.delete("APP_CUSTOMIZE.removeById", appId) > 0){
            // 清理对应缓存
            redisClient.deleteObject(companyId);
            return 1;
        }
        return 0;
    }

    @Override
    public List<ApplicationCustomize> findListByCompanyId(String companyId) {
        log.debug("查询应用列表，参数companyId={}", companyId);
        RedisClient redisClient = new RedisClient(CacheKey.PREFIX_APPLICATION_CUSTOMIZE);
        // 从缓存中取值
        List<ApplicationCustomize> list = null;
        Object json = redisClient.findObject(companyId);
        if(json == null || "".equals(json)){
            // 查询不到搜索数据库，并将结果放入缓存
            list = this.queryList("APP_CUSTOMIZE.findListByCompanyId", companyId);
            if(!CollectionUtils.isEmpty(list)){
                redisClient.saveObject(companyId, JacksonUtil.toJson(list), Constants.TIMEOUT_2D);
            }
        }else{
            list = JacksonUtil.listFromJson(json.toString(), ApplicationCustomize.class);
        }
        return list;
    }

    @Override
    public ApplicationCustomize findById(String companyId, String appId) {
        log.debug("根据企业id和appId查询指定自定义应用，参数companyId={}，appId={}", companyId, appId);
        List<ApplicationCustomize> list = this.findListByCompanyId(companyId);
        if(!CollectionUtils.isEmpty(list)){
            for (ApplicationCustomize app : list) {
                if(appId.equals(app.getId())){
                    return app;
                }
            }
        }
        return null;
    }

    @Override
    public ApplicationCustomize findByName(String companyId, String name) {
        log.debug("根据企业id和名称查询指定自定义应用，参数companyId={}，name={}", companyId, name);
        List<ApplicationCustomize> list = this.findListByCompanyId(companyId);
        if(!CollectionUtils.isEmpty(list)){
            for (ApplicationCustomize app : list) {
                if(name.equals(app.getName())){
                    return app;
                }
            }
        }
        return null;
    }

    @Override
    public int update(ApplicationCustomize app) {
        RedisClient redisClient = new RedisClient(CacheKey.PREFIX_APPLICATION_CUSTOMIZE);
        if(this.update("APP_CUSTOMIZE.update", app) > 0){
            redisClient.deleteObject(app.getCompanyId());
            return 1;
        }
        return 0;
    }
}