延續『WebSocket 雙向即時通訊 - 初探』，今天就以 Tornado 來寫個簡單的 WebSocket 範例。當 client 連到 server 後，會傳送 hello ，而 server 回應一樣的訊息，傳送到第五次，server 就把 client 斷掉。
Server (ws_server.py)
import tornado.ioloop
import tornado.web
from tornado import websocket
class WSHandler(websocket.WebSocketHandler):
count = 0
def open(self):
print "Client connected"
def on_message(self, msg):
print "[%d] Got message [%s] from client" % (self.count, msg)
if self.count == 4:
self.close()
return
# Write back message
self.write_message("[%d] Echo: %s" % (self.count, msg))
self.count += 1
def on_close(self):
print "Client disconnected"
application = tornado.web.Application([
(r"/", WSHandler),
])
if __name__ == "__main__":
application.listen(8888)
tornado.ioloop.IOLoop.instance().start()
Client (ws_client.py)
from tornado.websocket import websocket_connect
from tornado.ioloop import IOLoop
class ws_client():
conn = None # This is WebSocketClientConnection
def __init__(self):
websocket_connect('ws://localhost:8888/', callback=self.conn_cb)
def conn_cb(self, future):
self.conn = future.result()
self.conn.write_message("hello")
self.conn.read_message(self.read_cb)
def read_cb(self, future):
msg = future.result()
if msg is None:
print "Server disconnected"
IOLoop.instance().stop()
else:
print msg
self.conn.write_message("hello")
self.conn.read_message(self.read_cb)
if __name__ == '__main__':
ws_client()
IOLoop.instance().start()
