websocket 与 用户对接并发

实现 用户登录 对接 ,能处理多人数 聊天并发问题


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<div class="post-text" itemprop="text"> <p>I have studied the Godoc of the gorilla/websocket package.</p> <p>In the Godoc it is clearly stated that</p> <blockquote> <p>Concurrency Connections support one concurrent reader and one concurrent writer.</p> <p>Applications are responsible for ensuring that no more than one goroutine calls the write methods (NextWriter, SetWriteDeadline, WriteMessage, WriteJSON, EnableWriteCompression, SetCompressionLevel) concurrently and that no more than one goroutine calls the read methods (NextReader, SetReadDeadline, ReadMessage, ReadJSON, SetPongHandler, SetPingHandler) concurrently.</p> <p>The Close and WriteControl methods can be called concurrently with all other methods.</p> </blockquote> <p>However, in one of the example provided by the package</p> <pre><code>func (c *Conn) readPump() { defer func() { hub.unregister &lt;- c c.ws.Close() }() c.ws.SetReadLimit(maxMessageSize) c.ws.SetReadDeadline(time.Now().Add(pongWait)) c.ws.SetPongHandler(func(string) error { c.ws.SetReadDeadline(time.Now().Add(pongWait)); return nil }) for { _, message, err := c.ws.ReadMessage() if err != nil { if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway) { log.Printf("error: %v", err) } break } message = bytes.TrimSpace(bytes.Replace(message, newline, space, -1)) hub.broadcast &lt;- message } } </code></pre> <p>Source: <a href="https://github.com/gorilla/websocket/blob/a68708917c6a4f06314ab4e52493cc61359c9d42/examples/chat/conn.go#L50" rel="nofollow noreferrer">https://github.com/gorilla/websocket/blob/a68708917c6a4f06314ab4e52493cc61359c9d42/examples/chat/conn.go#L50</a></p> <p>This line</p> <pre><code>c.ws.SetPongHandler(func(string) error { c.ws.SetReadDeadline(time.Now().Add(pongWait)); return nil }) </code></pre> <p>and this line</p> <pre><code>_, message, err := c.ws.ReadMessage() </code></pre> <p>seems to be not synchronized because the first line is a callback function so it should be invoked in a Goroutine created in the package and the second line is executing in the Goroutine that invoke <code>serveWs</code></p> <p>More importantly, how should I ensure that no more than one goroutine calls the <code>SetReadDeadline</code>, <code>ReadMessage</code>, <code>SetPongHandler</code>, <code>SetPingHandler</code> concurrently?</p> <p>I tries to use a Mutex lock and lock it whenever I call the above functions, and unlock it afterwards, but quickly I realize a problem. It is usual (also in the example) that <code>ReadMessage</code> is being called in a for-loop. But if the Mutext is locked before the ReadMessage, then no other Read-functions can acquire the lock and execute until next message is received</p> <p>Is there any better way in handling this concurrency issue? Thanks in advance.</p> </div>


<div class="post-text" itemprop="text"> <p>I am using <code>github.com/gorilla/websocket</code> for websockets. I have this code</p> <pre><code>type CONN struct { Conn *websocket.Conn Username string hand []string mu *sync.Mutex } func (c *CONN) Send(messageType int, message []byte) error { c.mu.Lock() defer c.mu.Unlock() return c.Conn.WriteMessage(messageType, message) } //later... connection.Send(messageType, []byte("play")) connection.Send(messageType, []byte("[\"a\", \"b\", \"c\"]")) </code></pre> <p>These last two lines are giving me the error. Please let me know if you need any more code to figure it out. Here's the error:</p> <pre><code>2019/06/15 15:19:03 http: panic serving [::1]:56788: concurrent write to websocket connection goroutine 10 [running]: net/http.(*conn).serve.func1(0xc000164140) /usr/lib64/go/1.11/src/net/http/server.go:1746 +0xd0 panic(0x6654e0, 0x7125a0) /usr/lib64/go/1.11/src/runtime/panic.go:513 +0x1b9 github.com/gorilla/websocket.(*messageWriter).flushFrame(0xc000043a18, 0xc000016501, 0xc00001656c, 0x0, 0x4, 0x713e00, 0xc0001141e0) /home/victor/programs/goprograms/src/github.com/gorilla/websocket/conn.go:597 +0x631 github.com/gorilla/websocket.(*Conn).WriteMessage(0xc0001a4160, 0x1, 0xc000016568, 0x4, 0x8, 0x4, 0xc000016568) /home/victor/programs/goprograms/src/github.com/gorilla/websocket/conn.go:753 +0x24b main.(*CONN).Send(0xc00015c280, 0x1, 0xc000016568, 0x4, 0x8, 0x0, 0x0) /home/victor/programs/goprograms/src/v/asdf/network/main.go:32 +0x9e main.wsHandler(0x716960, 0xc00011e380, 0xc000116400) /home/victor/programs/goprograms/src/v/asdf/network/main.go:68 +0x501 net/http.HandlerFunc.ServeHTTP(0x6e1ab0, 0x716960, 0xc00011e380, 0xc000116400) /usr/lib64/go/1.11/src/net/http/server.go:1964 +0x44 net/http.(*ServeMux).ServeHTTP(0x8dadc0, 0x716960, 0xc00011e380, 0xc000116400) /usr/lib64/go/1.11/src/net/http/server.go:2361 +0x127 net/http.serverHandler.ServeHTTP(0xc00008d040, 0x716960, 0xc00011e380, 0xc000116400) /usr/lib64/go/1.11/src/net/http/server.go:2741 +0xab net/http.(*conn).serve(0xc000164140, 0x716b60, 0xc00005a800) /usr/lib64/go/1.11/src/net/http/server.go:1847 +0x646 created by net/http.(*Server).Serve /usr/lib64/go/1.11/src/net/http/server.go:2851 +0x2f5 </code></pre> <p><a href="https://gist.github.com/vityavv/a97ac9fe9192cb7107e6c7979f90cafc" rel="nofollow noreferrer">Here is the full code I am using</a> - line 75 is where the connection is set. I don't see how there could be multiple connections under one item in the map.</p> </div>


<div class="post-text" itemprop="text"> <p>Let's say i want to identify each user that initiate a connection to a php websocket server (Ratchet).</p> <p>Each user have an unique token in my database (not enough secure i know, but let's keep this example simple).</p> <p>I have to send this token when opening the connection to the WS server and check in my database if it match any user and if yes allowing to continue and storing the connection id of the WS to be able to link the user to the ws connection.</p> <p>Then connected user id 1 want's to send a message to connected user id 2</p> <p><strong>Do i have to search in the database the connection id of user 2 to be able to send the message ? or does there is an alternative, like a global array which stay in the memory or something and where the WS server can access it all time ? this would be less heavy than requesting the database if i just could store a link between "user Id" and "ws connection Id" directly in the memory or something</strong></p> </div>


看了网上很多springwebsocket的帖子,关于用户的session都是存在map或List里 比如 private static Map<String, WebSocketSession> users = new ConcurrentHashMap<String,WebSocketSession>(); 但是在做集群的时候,用户肯定不会再同一台服务器中存储。 我试着用redis存储WebSocketSession,但是WebSocketSession不能序列华,大家有什么好的思路吗?




我是用dva搭建的项目,项目中在model模块开启了websocket监听,接收到对应的消息类型,下发到对应的异步函数中 ![图片说明](https://img-ask.csdn.net/upload/201903/15/1552614682_13306.png) 在acceptMessage中更新我的state ![图片说明](https://img-ask.csdn.net/upload/201903/15/1552614746_639769.png) 但是websocket推送过来的消息并发较大,这样就导致在accpetMessage中获取的messageList的长度都是相同,最后更新的时候messageList就会丢掉很多消息, 在下初学react,希望大神指点迷津!

Gorilla WebSocket与golang.org/x/net/websocket的比较

<div class="post-text" itemprop="text"> <p>According <a href="https://github.com/gorilla/websocket#gorilla-websocket-compared-with-other-packages" rel="nofollow">Gorilla Websockets Project</a> it is not possible to send pings and pongs using <strong>golang.org/x/net/websocket</strong>. At the same time, the following is on the project page of <a href="http://godoc.org/golang.org/x/net/websocket" rel="nofollow">golang.org/x/net/websocket</a>:</p> <blockquote> <p>Package websocket implements a client and server for the WebSocket protocol as specified in RFC 6455.</p> </blockquote> <p>I am a little confused. <strong>golang.org/x/net/websocket</strong> implements RFC 6455 but can not send control frames (cancel, ping, pong) although this is specified in <a href="http://tools.ietf.org/html/rfc6455#section-5.5" rel="nofollow">RFC 6455 - Section Control Frames</a></p> <p>So what will happen if I use <strong>golang.org/x/net/websocket</strong> package. Will the connection abort after a timeout? In other words, how is it ensured here that the connection does not break off.</p> </div>

如何使用Golang Gorilla / mux托管并发Websocket连接?

<div class="post-text" itemprop="text"> <p>thanks in advance for any help or advice! </p> <p>I am building a chess application, the frontend is in Reactjs and backend is a server written in Golang using Gorilla mux library. The backend is a chess engine for the human user to play against. The react frontend creates a WebSocket connection with the server in the top-level constructor. </p> <p>The app works well for a single connection. However, upon opening a second browser tab, the first browser tab's Websocket connection is lost. </p> <p>The server reports the error, </p> <pre><code>read error: websocket: close 1001 (going away) </code></pre> <p>and then,</p> <pre><code>read error: read tcp\u003e127.0.0.1:64146: use of closed network connection </code></pre> <p>I've looked at the Gorrilla/mux documentation for websockets and am reading/writing all from the same function in order to avoid concurrent reads or writes on the same connection. </p> <p>React frontend constructor is here: </p> <pre><code>class Game extends React.Component { constructor(props) { super(props); this.state = { history: [{ position: this.props.chess.fen(), move: "", }], ply: 0, selectedSq: null, engineName: "", engineAuthor: "", uciOK: false, isReady: false, engineThinking: false, playersTurn: true, playerColor: WHITE, }; this.ws = websocketConnect("ws://localhost:8081/uci"); this.ws.onmessage = (event) =&gt; { const msg = event.data this.processEngineMessage(msg) } } </code></pre> <p>It is referencing websocket.js which is here: </p> <pre><code>export function websocketConnect(url) { const ws = new WebSocket(url); ws.addEventListener('open', (event) =&gt; { ws.send('uci'); }); return ws; } </code></pre> <p>Goland Websocket package is here</p> <pre><code>package websocket import ( "net/http" "github.com/namsral/flag" log "github.com/sirupsen/logrus" "github.com/gorilla/websocket" ) type WebsocketServer struct { upgrader websocket.Upgrader addr *string conn *websocket.Conn } func NewWebsocketServer() *WebsocketServer { w := new(WebsocketServer) w.addr = flag.String("addr", "localhost:8081", "http service address") flag.Parse() w.upgrader = websocket.Upgrader{} // use default options http.HandleFunc("/uci", w.uciHandler) return w } func (w *WebsocketServer) uciHandler(rw http.ResponseWriter, r *http.Request) { var err error log.Error("upgrading to websocket connection") w.upgrader.CheckOrigin = func(r *http.Request) bool { return true } w.conn, err = w.upgrader.Upgrade(rw, r, nil) if err != nil { log.Print("upgrade:", err) return } go w.UCI(rw, r) } func (w *WebsocketServer) Start() { log.Info("starting websocket server") http.ListenAndServe(*w.addr, nil) } func (w *WebsocketServer) CloseConnection() { w.conn.Close() } func (w *WebsocketServer) StartReader(channel chan string) { for { _, message, err := w.conn.ReadMessage() if err != nil { log.Println("read error:", err) break } log.Printf("recv: %s", message) channel &lt;- string(message) } } func (w *WebsocketServer) Write(msg string) { err := w.conn.WriteMessage(websocket.TextMessage, []byte(msg)) if err != nil { log.Println("write:", err) } } </code></pre> <p>Full code here: server: <a href="https://github.com/tonyOreglia/glee" rel="nofollow noreferrer">https://github.com/tonyOreglia/glee</a> frontend: <a href="https://github.com/tonyOreglia/chess-board-react" rel="nofollow noreferrer">https://github.com/tonyOreglia/chess-board-react</a></p> <p>I am hoping to be able to support multiple concurrent users using the website. It is currently hosted on DigitalOcean.</p> </div>


websocket一直连接着的话, 是不是session一直都不会超时呢? 现在web端需要使用websocket不断推送通知消息, 如果session永远不会超时, 那岂不是爆炸?

websocket 聊天室,怎么实时显示在线的用户


Golang WebSocket客户端

<div class="post-text" itemprop="text"> <p>I want to make client websocket connections to exertnal server each connection = goroutine and reader. I was looking informations on the internet but I found how to create server websocket tutorials. Can anyone be so kind and make a trivial example and walk me through. I am using standart golang libary <a href="https://golang.org/x/net/websocket" rel="nofollow">https://golang.org/x/net/websocket</a>.</p> <p>I created some code but when I closed one connection program exited with EOF information. I won't post the code because it's probably bad duo to the fact it was my first try.</p> <p>I know how to read/send message from websocket but I don't know how to create multiple connections.</p> <p>Any informations, examples would be appreciate, thanks for reading</p> </div>


<div class="post-text" itemprop="text"> <p><strong>How to authenticate the client connecting to the websocket server?</strong></p> <p>In http we could use Oauth 2.0 to authenticate the user and the client too. But in websocket I am not able to understand how to do so.</p> <p>As far as I can understand for authentication of the user connecting we could just ask the client to send a message with a token to authenticate the user. But how to prevent an un-identified client to connect to the server?</p> <p><strong>Isn't there any header for token based authentication for websocket</strong> as that would allow for both the authentication simultaneously just as in any Oauth 2.0 Rest api authentication. </p> </div>


<div class="post-text" itemprop="text"> <p>I got an error message: cannot use websocket.Handler(handler) (type websocket.Handler) as type func(http.ResponseWriter, *http.Request) in argument to mx.HandleFunc</p> <p>in following code</p> <pre><code>package main import ( "golang.org/x/net/websocket" "net/http" ) func handler(ws *websocket.Conn) { // TODO } func main() { mx := http.NewServeMux() mx.HandleFunc("/ws", websocket.Handler(handler)) // error http.ListenAndServe("localhost:8888", mx) } </code></pre> </div>

c++ 用WebSocket 实现通信

有一个需求 服务端是用java写的 用的WebSocket协议通信 服务商只提供了数据包的数据结构 我想知道websocket用c++怎么建立连接 会的最好提供下实例代码 拜托了


<div class="post-text" itemprop="text"> <p>I am very new to Go and have found myself working with sockets as my first project. This is a redundant question, but I have failed to understand how to send a websocket update to a specific client in Go (using Gorilla).</p> <p>The broad problem that I am trying to solve is - Building a typeahead using websockets and a search engine like ES/Lucene. I have maintained a bunch of indexes on my search engine and have a Go wrapper around it. When I started working on using websockets in Go, I have been finding almost all the examples showing broadcasting mechanism. When I tried to dig into this and tried to modify the example given in Gorilla's github <a href="https://github.com/gorilla/websocket/tree/master/examples/chat" rel="nofollow noreferrer">repo</a> based on the examples given in <a href="https://github.com/gorilla/websocket/issues/46" rel="nofollow noreferrer">this</a> thread and in this <a href="https://stackoverflow.com/questions/31598147/how-to-send-to-only-one-client-and-not-all-clients-using-go-and-gorilla-websocke">answer</a>, I don't seem to understand <code>connections</code> and how does that fit in <code>client.go</code></p> <p>Ideally, the way I would like to see this working is -</p> <ul> <li>A socket connection between the client and server is established</li> <li>Upon the client sending inputs via the socket, the server fetches it and throws into into a channel (Go channel)</li> <li>The indexing wrapper checks for this channel, and once there is something to fetch, the index is retrieved and written back to the socket</li> </ul> <p>How can the server uniquely identify the <code>Client</code>?</p> <p>I have used the examples given on Gorilla's Github <a href="https://github.com/gorilla/websocket/tree/master/examples/chat" rel="nofollow noreferrer">repo</a></p> <p>From my codebase <code>hub.go</code> has the following </p> <pre><code>type Hub struct { // Registered clients. clients map[*Client]bool // Inbound messages from the clients. broadcast chan []byte // Register requests from the clients. register chan *Client // Unregister requests from clients. unregister chan *Client connections map[string]*connection } func newHub() *Hub { return &amp;Hub{ broadcast: make(chan []byte), register: make(chan *Client), unregister: make(chan *Client), clients: make(map[*Client]bool), connection: make(map[*Client]bool), // is this alright? } } func (h *Hub) run() { for { select { case client := &lt;-h.register: h.clients[client] = true case client := &lt;-h.unregister: if _, ok := h.clients[client]; ok { delete(h.clients, client) close(client.send) } case message := &lt;-h.broadcast: for client := range h.connections { select { case client.send &lt;- message: default: close(client.send) delete(h.connections, client) } } } } } </code></pre> <p>and I am unsure with what I should be adding to <code>client.go</code></p> <pre><code>type Client struct { // unique ID for each client // id string // Hub object hub *Hub // The websocket connection. conn *websocket.Conn // Buffered channel of outbound messages. send chan []byte // connection --&gt; (what should the connection property be?) connection string } </code></pre> <p>Please note - I will be adding an <code>Id</code> field within the <code>Client</code> struct. How can I proceed from here?</p> </div>


<div class="post-text" itemprop="text"> <p>I've tried very basic websocket tutorial using ratchet php, exactly as shown in <a href="http://socketo.me/docs/hello-world" rel="nofollow">http://socketo.me/docs/hello-world</a></p> <p>Code for websocket server:</p> <pre><code>&lt;?php error_reporting(E_ALL); ini_set('display_errors', '1'); require 'vendor/autoload.php'; require 'chat.php'; use Ratchet\Server\IoServer; use HHWS\Chat; $server = IoServer::factory( new Chat(), 8080 ); $server-&gt;run(); </code></pre> <p>To run the server I did:</p> <pre><code>$ php ws-server.php </code></pre> <p>And to test the connection with the server I did:</p> <pre><code>telnet 8080 </code></pre> <p>This worked perfectly fine when tested LOCALLY. Users can chat using multiple telnet terminals. </p> <p>I then uploaded the code to live server. And the tried running the server. Then tried to connect to this server using telnet just like before, it couldn't connect. All it shows is "Trying.." message and then " Unable to connect to remote host: Connection timed out".</p> <p>I don't know why this is happening, and what the problem is. The code is exactly the same. And this is very basic hello world example I'm doing. Can anyone help me on this. Do using "Websockets" have any other requirements on the live server to work. </p> <p><strong>Update:</strong> Actually, the live server is <strong>Amazon EC2</strong>; does this require setting up additional things for websocket to work?</p> </div>


使用jmeter测试websocket时,依赖包和插件都已下载完成,已经放在了lib/ext目录下 新建websocket sampler之后,填写ip、port、path和请求参数,运行时报错 ![图片说明](https://img-ask.csdn.net/upload/201709/11/1505124708_475532.png) 请问这是什么原因,怎么解决?


<div class="post-text" itemprop="text"> <p>I want to store client websocket connection into <code>wsList</code>, and send response in uniform. but it will return "use of closed network connection". How to fix it? </p> <pre><code>import { "code.google.com/p/go.net/websocket" ... } var wsList []*websocket.Conn func WShandler(ws *websocket.Conn) { wsList = append(wsList, ws) go sendmsg() } func sendmsg() { for _, conn := range wsList { if err := websocket.JSON.Send(conn, outmsg); err != nil { fmt.Printf("%s", err) //"use of closed network connection" } } } </code></pre> </div>




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Ubuntu18.04.1安装一、准备工作1.下载Ubuntu18.04.1 LTS2.制作U盘启动盘3.准备 Ubuntu18.04.1 的硬盘空间二、安装Ubuntu18.04.1三、安装后的一些工作1.安装输入法2.更换软件源四、双系统如何卸载Ubuntu18.04.1新的改变功能快捷键合理的创建标题,有助于目录的生成如何改变文本的样式插入链接与图片如何插入一段漂亮的代码片生成一个适合你的列...


原理:    快速排序,说白了就是给基准数据找其正确索引位置的过程.    如下图所示,假设最开始的基准数据为数组第一个元素23,则首先用一个临时变量去存储基准数据,即tmp=23;然后分别从数组的两端扫描数组,设两个指示标志:low指向起始位置,high指向末尾.    首先从后半部分开始,如果扫描到的值大于基准数据就让high减1,如果发现有元素比该基准数据的值小(如上图中18&amp;lt...


【超实用课程内容】 本课程演示的是一套基于Java的SSM框架实现的图书管理系统,主要针对计算机相关专业的正在做毕设的学生与需要项目实战练习的java人群。详细介绍了图书管理系统的实现,包括:环境搭建、系统业务、技术实现、项目运行、功能演示、系统扩展等,以通俗易懂的方式,手把手的带你从零开始运行本套图书管理系统,该项目附带全部源码可作为毕设使用。 【课程如何观看?】 PC端:https://edu.csdn.net/course/detail/27513 移动端:CSDN 学院APP(注意不是CSDN APP哦) 本课程为录播课,课程2年有效观看时长,大家可以抓紧时间学习后一起讨论哦~ 【学员专享增值服务】 源码开放 课件、课程案例代码完全开放给你,你可以根据所学知识,自行修改、优化 下载方式:电脑登录https://edu.csdn.net/course/detail/27513,点击右下方课程资料、代码、课件等打包下载




&nbsp; &nbsp; &nbsp; &nbsp; 本课程为Python数据挖掘方向的入门课程,课程主要以真实数据为基础,详细介绍数据挖掘入门的流程和使用Python实现pandas与numpy在数据挖掘方向的运用,并深入学习如何运用scikit-learn调用常用的数据挖掘算法解决数据挖掘问题,为进一步深入学习数据挖掘打下扎实的基础。


想学好JAVA必须要报两万的培训班吗? Java大神勿入 如果你: 零基础想学JAVA却不知道从何入手 看了一堆书和视频却还是连JAVA的环境都搭建不起来 囊中羞涩面对两万起的JAVA培训班不忍直视 在职没有每天大块的时间专门学习JAVA 那么恭喜你找到组织了,在这里有: 1. 一群志同道合立志学好JAVA的同学一起学习讨论JAVA 2. 灵活机动的学习时间完成特定学习任务+每日编程实战练习 3. 热心助人的助教和讲师及时帮你解决问题,不按时完成作业小心助教老师的家访哦 上一张图看看前辈的感悟: &nbsp; &nbsp; 大家一定迫不及待想知道什么是极简JAVA学习营了吧,下面就来给大家说道说道: 什么是极简JAVA学习营? 1. 针对Java小白或者初级Java学习者; 2. 利用9天时间,每天1个小时时间; 3.通过 每日作业 / 组队PK / 助教答疑 / 实战编程 / 项目答辩 / 社群讨论 / 趣味知识抢答等方式让学员爱上学习编程 , 最终实现能独立开发一个基于控制台的‘库存管理系统’ 的学习模式 极简JAVA学习营是怎么学习的? &nbsp; 如何报名? 只要购买了极简JAVA一:JAVA入门就算报名成功! &nbsp;本期为第四期极简JAVA学习营,我们来看看往期学员的学习状态: 作业看这里~ &nbsp; 助教的作业报告是不是很专业 不交作业打屁屁 助教答疑是不是很用心 &nbsp; 有奖抢答大家玩的很嗨啊 &nbsp; &nbsp; 项目答辩终于开始啦 &nbsp; 优秀者的获奖感言 &nbsp; 这是答辩项目的效果 &nbsp; &nbsp; 这么细致的服务,这么好的氛围,这样的学习效果,需要多少钱呢? 不要1999,不要199,不要99,只要9.9 是的你没听错,只要9.9以上所有就都属于你了 如果你: 1、&nbsp;想学JAVA没有基础 2、&nbsp;想学JAVA没有整块的时间 3、&nbsp;想学JAVA没有足够的预算 还等什么?赶紧报名吧,抓紧抢位,本期只招300人,错过只有等时间待定的下一期了 &nbsp; 报名请加小助手微信:eduxy-1 &nbsp; &nbsp;


C++语言基础视频培训课程:本课与主讲者在大学开出的程序设计课程直接对接,准确把握知识点,注重教学视频与实践体系的结合,帮助初学者有效学习。本教程详细介绍C++语言中的封装、数据隐藏、继承、多态的实现等入门知识;主要包括类的声明、对象定义、构造函数和析构函数、运算符重载、继承和派生、多态性实现等。 课程需要有C语言程序设计的基础(可以利用本人开出的《C语言与程序设计》系列课学习)。学习者能够通过实践的方式,学会利用C++语言解决问题,具备进一步学习利用C++开发应用程序的基础。




本课程内容系统、全面、简洁、通俗易懂,通过2个多小时的介绍,让大家对软件测试有个系统的理解和认识,具备基本的软件测试理论基础。 主要内容分为5个部分: 1 软件测试概述,了解测试是什么、测试的对象、原则、流程、方法、模型;&nbsp; 2.常用的黑盒测试用例设计方法及示例演示;&nbsp; 3 常用白盒测试用例设计方法及示例演示;&nbsp; 4.自动化测试优缺点、使用范围及示例‘;&nbsp; 5.测试经验谈。


YOLOv3是一种基于深度学习的端到端实时目标检测方法,以速度快见长。本课程将手把手地教大家使用labelImg标注和使用YOLOv3训练自己的数据集。课程分为三个小项目:足球目标检测(单目标检测)、梅西目标检测(单目标检测)、足球和梅西同时目标检测(两目标检测)。 本课程的YOLOv3使用Darknet,在Ubuntu系统上做项目演示。包括:安装Darknet、给自己的数据集打标签、整理自己的数据集、修改配置文件、训练自己的数据集、测试训练出的网络模型、性能统计(mAP计算和画出PR曲线)和先验框聚类。 Darknet是使用C语言实现的轻型开源深度学习框架,依赖少,可移植性好,值得深入探究。 除本课程《YOLOv3目标检测实战:训练自己的数据集》外,本人推出了有关YOLOv3目标检测的系列课程,请持续关注该系列的其它课程视频,包括: 《YOLOv3目标检测实战:交通标志识别》 《YOLOv3目标检测:原理与源码解析》 《YOLOv3目标检测:网络模型改进方法》 敬请关注并选择学习!




《YOLOv3目标检测实战系列课程》旨在帮助大家掌握YOLOv3目标检测的训练、原理、源码与网络模型改进方法。 本课程的YOLOv3使用原作darknet(c语言编写),在Ubuntu系统上做项目演示。 本系列课程包括三门课: (1)《YOLOv3目标检测实战:训练自己的数据集》 包括:安装darknet、给自己的数据集打标签、整理自己的数据集、修改配置文件、训练自己的数据集、测试训练出的网络模型、性能统计(mAP计算和画出PR曲线)和先验框聚类。 (2)《YOLOv3目标检测:原理与源码解析》讲解YOLOv1、YOLOv2、YOLOv3的原理、程序流程并解析各层的源码。 (3)《YOLOv3目标检测:网络模型改进方法》讲解YOLOv3的改进方法,包括改进1:不显示指定类别目标的方法 (增加功能) ;改进2:合并BN层到卷积层 (加快推理速度) ; 改进3:使用GIoU指标和损失函数 (提高检测精度) ;改进4:tiny YOLOv3 (简化网络模型)并介绍 AlexeyAB/darknet项目。


一、下载MySQL 首先,去数据库的官网http://www.mysql.com下载MySQL。 点击进入后的首页如下:  然后点击downloads,community,选择MySQL Community Server。如下图:  滑到下面,找到Recommended Download,然后点击go to download page。如下图:  点击download进入下载页面选择No...


图像处理和计算机视觉的课程大家已经看过很多,但总有“听不透”,“用不了”的感觉。课程致力于创建人人都能听的懂的计算机视觉,通过生动、细腻的讲解配合实战演练,让学生真正学懂、用会。 【超实用课程内容】 课程内容分为三篇,包括视觉系统构成,图像处理基础,特征提取与描述,运动跟踪,位姿估计,三维重构等内容。课程理论与实战结合,注重教学内容的可视化和工程实践,为人工智能视觉研发及算法工程师等相关高薪职位就业打下坚实基础。 【课程如何观看?】 PC端:https://edu.csdn.net/course/detail/26281 移动端:CSDN 学院APP(注意不是CSDN APP哦) 本课程为录播课,课程2年有效观看时长,但是大家可以抓紧时间学习后一起讨论哦~ 【学员专享增值服务】 源码开放 课件、课程案例代码完全开放给你,你可以根据所学知识,自行修改、优化 下载方式:电脑登录https://edu.csdn.net/course/detail/26281,点击右下方课程资料、代码、课件等打包下载




安装第三方请求库 requests 被网站禁止了访问 原因是我们是Python过来的 重新给一段 可能还是存在用不了,使用网页的 编写代码 上面注意看匹配内容 User-Agent:请求对象 AppleWebKit:请求内核 Chrome浏览器 //请求网页 import requests import re //正则表达式 就是去不规则的网页里面提取有规律的信息 headers = { 'User-Agent':'存放浏览器里面的' } response = requests.get


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技术大佬:我去,你写的 switch 语句也太老土了吧

昨天早上通过远程的方式 review 了两名新来同事的代码,大部分代码都写得很漂亮,严谨的同时注释也很到位,这令我非常满意。但当我看到他们当中有一个人写的 switch 语句时,还是忍不住破口大骂:“我擦,小王,你丫写的 switch 语句也太老土了吧!” 来看看小王写的代码吧,看完不要骂我装逼啊。 private static String createPlayer(PlayerTypes p...

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