是否有用于JavaScript的Telnet库？ [英] Is there a Telnet library for JavaScript?

问题描述

我们有网络摄像头。它有一个HTTP服务器来提供当前图像。还有一个用于控制摄像机的Telnet接口（即触发器，焦点等）。我想在相机中添加一个HTML页面，它提供了一个简单的界面（我们已经有了我们编写的客户端软件）。我可以获取图像并显示它，但我也希望有控件使用Telnet接口来控制相机。因此，按钮后面可能有JavaScript代码，通过Telnet连接到摄像头（登录）并发出触发摄像头的命令。

We have a network camera. It has an HTTP server to provides the current image. There is also a Telnet interface for controlling the camera (i.e. trigger, focus, etc.). I would like to add an HTML page to the camera that would provide a simple interface (we already have client software we write). I can "GET" the image and display that, but I would also like to have controls that use the Telnet interface to control the camera. So a button might have JavaScript code behind it that connects to the camera via Telnet (logs in) and issues the command to trigger the camera.

我知道JavaScript /浏览器支持通过 XMLHttpRequest的。在这种情况下，我将寻找在端口23上打开一个套接字并发送文本。我也知道我可以通过Flash，Java或其他技术来实现这一点，但我更愿意只使用JavaScript。如果可能的话。

I know that JavaScript/browsers support connecting to the same host via XMLHttpRequest. In this case I would be looking to open a socket on port 23 and send text. I also know that I can do this through Flash, Java, or some other technology, but I would prefer to use JavaScript only. If that is possible.

推荐答案

Thomaschaaf是正确的，而HTML5引入了websockets，你会发现他们仍然需要特殊的服务器支持，因为他们打开套接字后发布HTTP样式信息：

Thomaschaaf is correct, while HTML5 introduces websockets you'll find they still require special server support as they post HTTP style information upon opening the socket:

JS / HTML5 WebSocket：无HTTP呼叫连接

目前，拥有真正套接字的最佳方法是

The best way, currently, to have true sockets is to either

• 在执行实际套接字工作的网页上使用flash或Java组件。


• 使用带有websockets的代理服务器，可以处理websockets的额外协议开销，并使用普通套接字连接到真正的tcp / ip端口。

mat链接的jsterm示例执行后者，如果您的网络摄像头位于防火墙后面，那么在没有实现其他服务器的情况下它将不适用于您的情况。

The jsterm example Matt linked does the latter, and if your webcans are behind a firewall it will not work in your situation without also implementing another server.

有些库实现了第一种方法，其中两种是为方便起见而链接的，其他很多都是使用搜索引擎找到的：

There are libraries that implement the first method, two are linked here for convenience, many others can be found using a search engine:

http://stephengware.com/proj/javasocketbridge/ （Java）

http：// matthaynes.net/blog/2008/07/17/socketbridge-flash-javascript-socket-bridge/ （Flash）

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