FastAPI WebSocket 简单演示

返回上一步 / in None

效果#

简单效果演示

WebSocket 服务#

使用Python FastAPI框架官网demo
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from typing import List

from fastapi import FastAPI, WebSocket, WebSocketDisconnect

app = FastAPI()


class ConnectionManager:
    def __init__(self):
        # 存放激活的ws连接对象
        self.active_connections: List[WebSocket] = []

    async def connect(self, ws: WebSocket):
        # 等待连接
        await ws.accept()
        # 存储ws连接对象
        self.active_connections.append(ws)

    def disconnect(self, ws: WebSocket):
        # 关闭时 移除ws对象
        self.active_connections.remove(ws)

    @staticmethod
    async def send_personal_message(message: str, ws: WebSocket):
        # 发送个人消息
        await ws.send_text(message)

    async def broadcast(self, message: str):
        # 广播消息
        for connection in self.active_connections:
            await connection.send_text(message)


manager = ConnectionManager()


@app.websocket("/ws/{user}")
async def websocket_endpoint(websocket: WebSocket, user: str):

    await manager.connect(websocket)

    await manager.broadcast(f"用户{user}进入聊天室")

    try:
        while True:
            data = await websocket.receive_text()
            await manager.send_personal_message(f"你说了: {data}", websocket)
            await manager.broadcast(f"用户:{user} 说: {data}")

    except WebSocketDisconnect:
        manager.disconnect(websocket)
        await manager.broadcast(f"用户-{user}-离开")

if __name__ == "__main__":
    import uvicorn
    # 官方推荐是用命令后启动 uvicorn main:app --host=127.0.0.1 --port=8010 --reload
    uvicorn.run(app='main:app', host="127.0.0.1", port=8010, reload=True, debug=True)

前端#

前端只是简单使用演示, 没有对连接做鉴权处理。
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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>聊天1</title>
</head>
<body>
<h1>User1 Chat</h1>
<form action="" onsubmit="sendMessage(event)">
    <input type="text" id="messageText" autocomplete="off"/>
    <button>Send</button>
</form>
<ul id='messages'>
</ul>

<script>
    var ws = new WebSocket("ws://127.0.0.1:8010/ws/user1");

    ws.onmessage = function(event) {
        var messages = document.getElementById('messages')
        var message = document.createElement('li')
        var content = document.createTextNode(event.data)
        message.appendChild(content)
        messages.appendChild(message)
    };
    function sendMessage(event) {
        var input = document.getElementById("messageText")
        ws.send(input.value)
        input.value = ''
        event.preventDefault()
    }
</script>

</body>
</html>
用户2， 和上面的用户1没什么区别，只是连接WebSocket 参数变化区分， 其他地方一样，就是url参数变化了。
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<script>
    var ws = new WebSocket("ws://127.0.0.1:8010/ws/user2");

    ws.onmessage = function(event) {
        var messages = document.getElementById('messages')
        var message = document.createElement('li')
        var content = document.createTextNode(event.data)
        message.appendChild(content)
        messages.appendChild(message)
    };
    function sendMessage(event) {
        var input = document.getElementById("messageText")
        ws.send(input.value)
        input.value = ''
        event.preventDefault()
    }
</script>

总结#

WebSocket使用还是很简单的，但是封装鉴权，前端断线重连等等操作还是很耗时的。
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