所以我一直在尝试在我的flutter应用程序和FastAPI之间建立一个WebSocket连接。我认为问题出在Flutter身上。
到目前为止,我已经尝试了Flutter包socket_io_client,web_socket_channel和WebSocket_manager没有awail。
我怀疑这可能与应用程序架构有关,也许...有点不知所措。
以下是Flutter误差:
I/onListen(26110): arguments: null
I/EventStreamHandler(26110): 🔴 event sink
I/onListen(26110): arguments: null
I/EventStreamHandler(26110): 🔴 event sink
W/System.err(26110): java.net.ProtocolException: Expected HTTP 101 response but was '403 Forbidden'
W/System.err(26110): at okhttp3.internal.ws.RealWebSocket.checkUpgradeSuccess$okhttp(RealWebSocket.kt:185)
W/System.err(26110): at okhttp3.internal.ws.RealWebSocket$connect$1.onResponse(RealWebSocket.kt:156)
W/System.err(26110): at okhttp3.RealCall$AsyncCall.run(RealCall.kt:140)
W/System.err(26110): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
W/System.err(26110): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
W/System.err(26110): at java.lang.Thread.run(Thread.java:923)
I/EventStreamHandler(26110): ✅ sink is not null
I/flutter (26110): websocket closed
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我知道它说403禁止来自我的API,虽然我知道WebSocket连接是可能的,因为我已经用JavaScript测试过了。
下面是API的日志:
DEBUG | websockets.protocol:__init__:244 - server - state = CONNECTING
DEBUG | websockets.protocol:connection_made:1340 - server - event = connection_made(<_SelectorSocketTransport fd=484 read=polling write=<idle, bufsize=0>>)
DEBUG | websockets.protocol:data_received:1412 - server - event = data_received(<422 bytes>)
DEBUG | websockets.server:read_http_request:237 - server < GET /11 HTTP/1.1
DEBUG | websockets.server:read_http_request:238 - server < Headers([('authorization', 'Bearer *JWTTOKEN*'), ('upgrade', 'websocket'), ('connection', 'Upgrade'), ('sec-websocket-key', 'zytoCsWVlcmsKghL5XFEdA=='), ('sec-websocket-version', '13'), ('host', '10.0.2.2:8000'), ('accept-encoding', 'gzip'), ('user-agent', 'okhttp/4.3.1')])
INFO | uvicorn.protocols.websockets.websockets_impl:asgi_send:198 - ('127.0.0.1', 50772) - "WebSocket /11" 403
DEBUG | websockets.server:write_http_response:256 - server > HTTP/1.1 403 Forbidden
DEBUG | websockets.server:write_http_response:257 - server > Headers([('Date', 'Fri, 09 Apr 2021 11:10:11 GMT'), ('Server', 'Python/3.7 websockets/8.1'), ('Content-Length', '0'), ('Content-Type', 'text/plain'), ('Connection', 'close')])
DEBUG | websockets.server:write_http_response:267 - server > body (0 bytes)
DEBUG | websockets.protocol:fail_connection:1261 - server ! failing CONNECTING WebSocket connection with code 1006
DEBUG | websockets.protocol:connection_lost:1354 - server - event = connection_lost(None)
DEBUG | websockets.protocol:connection_lost:1356 - server - state = CLOSED
DEBUG | websockets.protocol:connection_lost:1365 - server x code = 1006, reason = [no reason]
型
我在一个类中有所有的WebSocket代码,它被“提供”,即WebSocketState:
return runApp(
MultiProvider(
providers: [
Provider<AuthenticationState>(
create: (_) => new AuthenticationState(),
),
Provider<WebSocketState>(
create: (_) => new WebSocketState(),
),
],
child: MyApp(),
),
);
型
WebSocketState:
class WebSocketState {
final _socketMessage = StreamController<Message>();
Sink<Message> get getMessageSink => _socketMessage.sink;
Stream<Message> get getMessageStream => _socketMessage.stream;
WebsocketManager socket;
bool isConnected() => true;
void connectAndListen(int userId) async {
var token = await secureStorage.read(key: 'token');
socket = WebsocketManager(
'ws://10.0.2.2:8000/$userId', {'Authorization': 'Bearer $token'});
socket.onClose((dynamic message) {
print('websocket closed');
});
// Listen to server messages
socket.onMessage((dynamic message) {
print("Message = " + message.toString());
});
// Connect to server
socket.connect();
}
void dispose() {
_socketMessage.close();
socket.close();
}
}
型
connectAndListen方法在用户通过身份验证后在第一个/主页面中调用,然后在其他页面中使用WebSocket。
@override
void didChangeDependencies() {
super.didChangeDependencies();
Provider.of<WebSocketState>(context, listen: false).connectAndListen(
Provider.of<AuthenticationState>(context, listen: false).id);
}
型
API WebSocket 'class':
WebSocket_notifier.py
from enum import Enum
import json
from typing import List
class SocketClient:
def __init__(self, user_id: int, websocket: WebSocket):
self.user_id = user_id
self.websocket = websocket
class WSObjects(Enum):
Message = 0
class Notifier:
def __init__(self):
self.connections: List[SocketClient] = []
self.generator = self.get_notification_generator()
async def get_notification_generator(self):
while True:
message = yield
await self._notify(message)
async def push(self, msg: str):
await self.generator.asend(msg)
async def connect(self, user_id: int, websocket: WebSocket):
await websocket.accept()
self.connections.append(SocketClient(user_id, websocket))
def remove(self, websocket: WebSocket):
client: SocketClient
for x in self.connections:
if x.websocket == websocket:
client = x
self.connections.remove(client)
async def _notify(self, message: str):
living_connections = []
while len(self.connections) > 0:
# Looping like this is necessary in case a disconnection is handled
# during await websocket.send_text(message)
client = self.connections.pop()
await client.websocket.send_text(message)
living_connections.append(client)
self.connections = living_connections
async def send(self, user_id: int, info: WSObjects, json_object: dict):
print("WS send running")
msg = {
"info": info,
"data": json_object
}
print("connections count: " + str(len(self.connections)))
for client in self.connections:
if client.user_id == user_id:
print("WS sending msg to ${client.user_id}")
await client.websocket.send_text(json.dumps(msg))
break
notifier = Notifier()
型
API main:
from fastapi import FastAPI
from websocket_notifier import notifier
from starlette.websockets import WebSocket, WebSocketDisconnect
app = FastAPI()
@app.get("/")
async def root():
return {"message": "Root"}
@app.websocket("/ws/{user_id}")
async def websocket_endpoint(user_id: int, websocket: WebSocket):
await notifier.connect(user_id, websocket)
try:
while True:
data = await websocket.receive_text()
await websocket.send_text(f"Message text was: {data}")
except WebSocketDisconnect:
notifier.remove(websocket)
@app.on_event("startup")
async def startup():
# Prime the push notification generator
await notifier.generator.asend(None)
型
你知道我做错了什么吗?(我用过的其他flutter WebSocket包与我展示的一样)
3条答案
按热度按时间e0bqpujr1#
通过大量的测试,我终于找到了一种方法,让WebSocket与我的Flutter应用程序和FastAPI一起工作。https://github.com/tiangolo/fastapi/issues/129
不得不尝试一些不同的东西从这个问题的线程。但最终还是使用了python-socketio。我不得不使用一个较低版本的python-socketio来兼容最新的flutter socket_io_client包。
oiopk7p52#
对于那些有同样问题的人,也请检查#2639。APIRouter的前缀在WebSocket decorator中不起作用。
enxuqcxy3#
原因可能就在路上。尽量避免在服务器和客户端中尾随
/
。自动重定向,例如/ws/user/
->/ws/user
可以删除对连接很重要的头。如果整个路径是通过APIRouter.prefix定义的,那么在端点装饰器中使用空路径''
而不是'/'
。