在JavaScript中使用WebSocket时出错

Question

I am currently working on a mobile app created with Cordova. It uses sockets to connect to another device of ours to communicate with it. We currently use chrome.sockets.tcp with this plugin .

It connects fine, however on Android devices has a problem disconnecting. It's not a timeout issue as the disconnect can happen anywhere from 20 to 30 seconds up to 10 to 15 minutes. It will even disconnect while I am downloading data making 2 to 3 requests every second. There are no errors and nothing in the log to indicate what happened. It appears that chrome.sockets.tcp does not have much in the way of connection status reporting so I can figure out why its dropping the connection.

So I tried to make the switch to JavaScript's WebSocket to see if it helps with the disconnect issue. Or at least it appears to provide more connection status information. But I can't get it to connect. I get Error during WebSocket handshake: net::ERR_INVALID_HTTP_RESPONSE . Here is my code:

var socket = new WebSocket("ws://" + IP + ":" + port);
socket.protocol = "soap";

socket.onclose = function(event) {
    console.log(event);
};
socket.onerror = function(event) {
    console.log(event);
};
socket.onmessage = function(event) {
    console.log(event);
};
socket.onopen = function(event) {
    console.log(event);
};

I've done some research and it seems that I might have to set a protocol using socket.protocol = "aProtocol"; but after I set the protocol and set a break point socket.protocol is still "" even after calling socket.protocol = "soap"; . It also does not work to set the protocol using the constructor.

Can anyone provide me with either some reasons why chrome.sockets.tcp has such a disconnect problem on Android but not iOS OR any reasons why using JavaScript's native WebSocket fails to connect? Any help is greatly appreciated.

Answer 1

尝试在构造函数中传递子协议：

var socket = new WebSocket("ws://" + SSID + ":" + port, "soap");

Answer 2

Turns out it was due to our socket server being a TCP socket server. TCP and WebSockets do not at all work together as there is a completely different process for making the connection. So I ended up crating a TCP socket Cordova plugin instead.