南山最专业的网站建设,山药云搭建网站,网站开发需求分析参考文献,视频网站建设的意义论文13-1 WebSocket是什么
WebSocket简介#xff1a; WebSocket是一种在单个TCP连接上进行全双工通信的协议。 WebSocket使得客户端和服务器之间的数据交换变得更加简单#xff0c;允许服务端主动向客户端推送数据。 在WebSocket API中#xff0c;浏览器和服务器只需要完成一…13-1 WebSocket是什么
WebSocket简介 WebSocket是一种在单个TCP连接上进行全双工通信的协议。 WebSocket使得客户端和服务器之间的数据交换变得更加简单允许服务端主动向客户端推送数据。 在WebSocket API中浏览器和服务器只需要完成一次握手两者之间就直接可以创建持久性的连接并进行双向数据传输。
WebSocket和HTTP的相同点和不同点 WebSocket和HTTP都是解决 客户端-服务端 通信的网络协议。 HTTP是单向的客户端先发起请求服务端收到请求后再处理这个请求返回响应结果即先有请求再有响应且是一个请求对应一个响应请求时建立连接响应后断开连接。 WebSocket是双向的客户端发起请求经过三次握手连接后客户端和服务端就会基于这个连接保持通信都可以主动向对方发消息。任何一端都可以主动断开这个连接。 HTTP是无状态的WebSocket是有状态的。即如果使用WebSocket那么只要建立了连接每次通信时服务端都知道在和谁通信不需要借助Cookie或seesion或jwt等登录认证方式。 参考https://www.geeksforgeeks.org/what-is-web-socket-and-how-it-is-different-from-the-http/ WebSocket的应用
实时web应用游戏聊天软件等等
13-2 WebSocket聊天室简易版 使用FastAPI演示浏览器和服务端基于WebSocket建立连接并双向通信。 前端代码无需掌握只要了解它在干什么事情即可。 示例中我们使用 HTMLResponse通过接口的方式把前端代码响应的浏览器上但其实直接写一个html文件手动打开也可以的。 后端使用WebSocket需要使用WebSocket这个对象常用如下三个 协程函数。
await websocket.accept() # 建立连接
data await websocket.receive_text() # 收消息
await websocket.send_text() # 发消息想要在fastAPI中使用websocket 需要安装标准版的uvicorn
pip3 install uvicorn[standard]实例简单版聊天
from fastapi import FastAPI, WebSocket
from fastapi.responses import HTMLResponseapp FastAPI()html
!DOCTYPE html
htmlheadtitleChat/title/headbodyh1WebSocket Chat/h1form action οnsubmitsendMessage(event)input typetext idmessageText autocompleteoff/buttonSend/button/formul idmessages/ulscriptvar ws new WebSocket(ws://localhost:8000/ws);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
app.get(/)
async def get():return HTMLResponse(html)app.websocket(/ws)
async def websocket_endpoint(websocket: WebSocket):await websocket.accept()while True:data await websocket.receive_text()await websocket.send_text(fMessage text was: {data})13-3 WebSocket多人在线聊天室
实现多人在线聊天室处理客户端下线通知使用时间戳做客户端id
示例1多人在线聊天室
from typing import Listfrom fastapi import FastAPI, WebSocket, WebSocketDisconnect
from fastapi.responses import HTMLResponseapp FastAPI()html
!DOCTYPE html
htmlheadtitleChat/title/headbodyh1WebSocket Chat/h1h2Your ID: span idws-id/span/h2form action οnsubmitsendMessage(event)input typetext idmessageText autocompleteoff/buttonSend/button/formul idmessages/ulscriptvar client_id Date.now()document.querySelector(#ws-id).textContent client_id;var ws new WebSocket(ws://localhost:8000/ws/${client_id});ws.onmessage function(event) {var messages document.getElementById(messages)var message document.createElement(li)var content document.createTextNode(event.data)message.appendChild(content)messages.appendChild(message)};function sendMessage(event) {var input document.getElementById(messageText)ws.send(input.value)input.value event.preventDefault()}/script/body
/html
class ConnectionManager:def __init__(self):self.active_connections: List[WebSocket] []async def connect(self, websocket: WebSocket):await websocket.accept()self.active_connections.append(websocket)def disconnect(self, websocket: WebSocket):self.active_connections.remove(websocket)async def send_personal_message(self, message: str, websocket: WebSocket):await websocket.send_text(message)async def broadcast(self, message: str):for connection in self.active_connections:await connection.send_text(message)manager ConnectionManager()app.get(/)
async def get():return HTMLResponse(html)app.websocket(/ws/{client_id})
async def websocket_endpoint(websocket: WebSocket, client_id: int):await manager.connect(websocket) # 接收连接try:while True:data await websocket.receive_text() # 接收数据await manager.send_personal_message(fYou wrote: {data}, websocket) # 自己发的消息自己看到await manager.broadcast(fClient #{client_id} says: {data}) # 广播发给所有在线的客户端except WebSocketDisconnect:manager.disconnect(websocket) # 断开连接await manager.broadcast(fClient #{client_id} left the chat) # 广播示例2优化自己发的消息不重复展示
from typing import Listfrom fastapi import FastAPI, WebSocket, WebSocketDisconnect
from fastapi.responses import HTMLResponseapp FastAPI()html
!DOCTYPE html
htmlheadtitleChat/title/headbodyh1WebSocket Chat/h1h2Your ID: span idws-id/span/h2form action οnsubmitsendMessage(event)input typetext idmessageText autocompleteoff/buttonSend/button/formul idmessages/ulscriptvar client_id Date.now()document.querySelector(#ws-id).textContent client_id;var ws new WebSocket(ws://localhost:8000/ws/${client_id});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
class ConnectionManager:def __init__(self):self.active_connections: List[WebSocket] []async def connect(self, websocket: WebSocket):await websocket.accept()self.active_connections.append(websocket) # 收集有所的在线客户端def disconnect(self, websocket: WebSocket):self.active_connections.remove(websocket) # 当客户端断线时更新在线客户端列表async def send_personal_message(self, message: str, websocket: WebSocket):await websocket.send_text(message)async def broadcast(self, message: str, websocket: WebSocket):for connection in self.active_connections:if connection websocket: # 判断下如果是自己就不再发送消息continueawait connection.send_text(message)manager ConnectionManager()app.get(/)
async def get():return HTMLResponse(html)app.websocket(/ws/{client_id})
async def websocket_endpoint(websocket: WebSocket, client_id: int):await manager.connect(websocket)try:while True:data await websocket.receive_text()await manager.send_personal_message(fYou wrote: {data}, websocket)await manager.broadcast(fClient #{client_id} says: {data}, websocket)except WebSocketDisconnect:manager.disconnect(websocket)await manager.broadcast(fClient #{client_id} left the chat, websocket)
