javascript 保持 WebSocket 连接处于活动状态
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Keeping the WebSocket connection alive
提问by Dreen
I'm doing a study on WebSocket protocol and trying to implement a simple ECHO service for now with Python on the backend. It seems to work fine but the connection drops right after being established.
我正在研究 WebSocket 协议，并尝试在后端使用 Python 实现一个简单的 ECHO 服务。它似乎工作正常，但连接建立后立即断开。
Here is my client:
这是我的客户：
<!doctype html>
<head>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
function Client()
{
//var ws = new WebSocket("ws://echo.websocket.org"); // this works fine
var ws = new WebSocket("ws://localhost:8000");
ws.onopen = function(e){ $("#response").append(">> Connected<br />"); }
ws.onclose = function(e){ $("#response").append(">> Disconnected<br />"); }
ws.onerror = function(e){ $("#response").append(">> ERROR: " + e.data + "<br />"); }
ws.onmessage = function(e){ $("#response").append("> " + e.data + "<br />"); }
this.sendCmd = function()
{
var message = $("#cmd").val();
$("#response").append(message + "<br />");
ws.send(message);
return false;
}
this.disconnect = function()
{
ws.close();
}
}
// onload
$(function() {
$("#response").append(">> Connecting<br />");
client = new Client();
$("#send").click(client.sendCmd);
$("#disconnect").click(client.disconnect);
});
</script>
</head>
<body>
<input type="text" name="cmd" id="cmd" /> | <a href="#" id="send">Send</a> | <a href="#" id="disconnect">Disconnect</a><br />
<hr />
<span id="response"></span>
</body>
</html>
Here is the server:
这是服务器：
import SocketServer
import socket
from hashlib import sha1
from base64 import b64encode
PORT = 8000
MAGIC = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
class Handler(SocketServer.BaseRequestHandler):
# incoming connection
def setup(self):
self.data = self.request.recv(1024).strip()
print "connection established", self.client_address
self.headers = self.headsToDict(self.data.split("\n"))
# incoming message
def handle(self):
# its a handshake
if "Upgrade" in self.headers and self.headers["Upgrade"] == "websocket":
key = self.headers["Sec-WebSocket-Key"]
accept = b64encode(sha1(key + MAGIC).hexdigest().decode('hex'))
response = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n" # "HTTP/1.1 101 Switching Protocols\r\n"
print "< HTTP/1.1 101 Web Socket Protocol Handshake" # "HTTP/1.1 101 Switching Protocols\r\n"
response += "Upgrade: websocket\r\n"
print "< Upgrade: websocket"
response += "Connection: Upgrade\r\n"
print "< Connection: Upgrade"
response += "Sec-WebSocket-Accept: "+accept+"\r\n\r\n"
print "< Sec-WebSocket-Accept: "+accept
self.request.send(response)
# its a normal message, echo it back
else:
print self.data
self.request.send(self.data)
# connection dropped
def finish(self):
print "connection lost", self.client_address
# convert a list of headers to a dictionary for convenience
def headsToDict(self, hdata):
rzygi = {}
for item in hdata:
print '>', item
item = item.split(':')
if len(item) > 1:
rzygi[item[0].strip()] = item[1].strip()
return rzygi
server = SocketServer.TCPServer(("", PORT), Handler)
server.socket_type = socket.SOCK_STREAM # didnt help
print "serving at port", PORT
try:
server.serve_forever()
except KeyboardInterrupt:
pass
server.server_close()
As mentioned, the connection is established successfully but then drops straight away, which makes me think the code is correct but there is something missing to keep the socket open. Here is the server output:
如前所述，连接已成功建立，但随后立即断开，这让我认为代码是正确的，但缺少保持套接字打开的功能。这是服务器输出：
serving at port 8000
connection established ('127.0.0.1', 52633)
> GET / HTTP/1.1
> Upgrade: websocket
> Connection: Upgrade
> Host: localhost:8000
> Sec-WebSocket-Origin: http://localhost
> Sec-WebSocket-Key: qWGnhdFQ6l8Xs9awgQURfA==
> Sec-WebSocket-Version: 8
< HTTP/1.1 101 Web Socket Protocol Handshake
< Upgrade: websocket
< Connection: Upgrade
< Sec-WebSocket-Accept: fei4E4LQvPnf4y2ilebVsxRofvc=
connection lost ('127.0.0.1', 52633)
How do I keep the socket open?
我如何保持插座打开？
edit: server code comments
编辑：服务器代码注释
采纳答案by pimvdb
The connection is closed each time after handle. You should rather stay there reading incoming data:
每次在 之后关闭连接handle。你应该呆在那里阅读传入的数据：
# incoming connection
def setup(self):
print "connection established", self.client_address
def handle(self):
while 1:
try:
self.data = self.request.recv(1024).strip()
# incoming message
self.headers = self.headsToDict(self.data.split("\r\n"))
# its a handshake
if "Upgrade" in self.headers and self.headers["Upgrade"] == "websocket":
key = self.headers["Sec-WebSocket-Key"]
accept = b64encode(sha1(key + MAGIC).hexdigest().decode('hex'))
response = "HTTP/1.1 101 Switching Protocols\r\n"
response += "Upgrade: websocket\r\n"
response += "Connection: Upgrade\r\n"
response += "Sec-WebSocket-Accept: "+accept+"\r\n\r\n"
print response
self.request.send(response)
# its a normal message, echo it back
else:
print self.data
self.request.send(self.data)
except:
print "except"
break
