@Test
public void test2(){List list = new ArrayList<String>();list.addAll(null);
}本文来自博客园,作者:chuangzhou,转载请注明原文链接:https://www.cnblogs.com/czzz/p/18624219
1.更换yum源
备份(官方停止维护,无所谓了),更改配置文件,清除缓存,建立缓存
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backupCentOS-Base.repo
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the clien…