报错内容：
The unit files have no installation config (WantedBy=, RequiredBy=, Also=, Alias= settings in the [Install] section, and DefaultInstance= for template units). This means they are not meant t...
原网页地址：
How To Limit Rate of Connections (Requests) in NGINX (tecmint.com)
The following configuration example shows limiting the rate of request to a web application API. The shared memory size is ...
仅是简单记录，不代表这样是正确的。
错误的方法，使用StringUtils.isEmpty判断，会报空指针
if (StringUtils.isEmpty(entity.getVersionCode().toString())){
entity.setVersionCode(1L);
}
正确的方法：
if (ObjectUtil.isNull(en...
![systemctl enable rc-local.service报错：The unit files have no installation config (WantedBy=, RequiredBy=, Also=, Alias= settings in the [Install] section, and DefaultInstance= for template units). This](https://www.144d.com/content/templates/J2/images/random/15.jpg "systemctl enable rc-local.service报错：The unit files have no installation config (WantedBy=, RequiredBy=, Also=, Alias= settings in the [Install] section, and DefaultInstance= for template units). This")
