不小心把自己原先的项目里的pom文件给覆盖了。于是重构，但出现如下错误：
Project build error: Non-resolvable parent POM for com.kaspar:siyunlian-master:0.0.1-SNAPSHOT: Failure to find org.springframework.boot:spring-boot-starter-parent:pom:2.2.6.RELEASE in http:// maven.aliyun.com/nexus/content/repositories/central/ was cached in the local repository, resolution will not be reattempted until the update interval of alimaven has elapsed or updates are forced and 'parent.relativePath' points at no local POM
修改版本号错误消失。
然后重新update 项目。错误解决。