> For the complete documentation index, see [llms.txt](https://socket.gitbook.io/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://socket.gitbook.io/docs/4-fu-wu-duan-apiserverapi/4.1-server/server_close_callback.md).

# 4.1.17 服务器关闭回调 server\_close\_callback

* `callback`(Function)

关闭socket.io服务器。`callback(回调)`参数是可选的，将在关闭所有连接时调用。

```javascript
const Server= require('socket.io');
const PORT=3030;
const server= require('http').Server()

const io= Server(PORT);

io.close() //关闭当前的服务器

server.listen(PORT);// 释放端口

io=Server(server);
```