Implement (background Active) message push using the spring boot +websocket

the use of this webscoket must ensure that the production environment is compatible/supported. Use this webscoket to ensure that the production environment is compatible/supported. Use this webscoket to ensure that the production environment is compatible/supported. The main is tomcat compatibility and support.

There is a need: The app user generates an operation that needs to be perceived by some people in the backend management system (shown as a page message).

The earliest version is the background management system rotation, every once in a while rotation, because the message is important, every few seconds to check. This is obviously very indecent. Consumes a lot of resources and most of the requests are useless (no data is available) and they are very blue and thin.

Later, I wanted to use the message to push the way to deal with this logic. The user creates a target operation in the app, which generates a message that is pushed to the corresponding user in the backend management system.

Then I looked for a variety of materials, a colleague recommended DWZ, and later found that it was not very suitable for the current project (maybe I just don't know how to implement it).

Later learned that websocket, the Internet read a lot of documents are similar to chat room scenes, some different. In this, I mainly focus on the introduction of the server under the active push , by the service side to trigger.

WebSocket main achievable scenarios:

1, web chat room

2, Server message real-time notification

There should be a lot of WebSocket using the tomcat8+h5 environment under the introduction.

PS: My own test environment is TOMCAT7 This is not the case. wang115032337 "https://blog.csdn.net/wang115032337" this friend in his environment, TOMCAT7/8 can use the writing of this article, but need to remove Websocketconfig class (there are articles that TOMCAT7 and 8 support for the websocket is different, I do not understand)

Words do not say, directly on the code, want to know more about WebSocket, please refer to the relevant introduction.

1.pom

	<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId> Spring-boot-starter-websocket</artifactid>
        </dependency>

2. The use of @serverendpoint to create WebSocket endpoint ( wang115032337 This friend in his environment to join the @serverendpoint class will error, directly delete the still available）

@Configuration public
class Websocketconfig {
    @Bean public
    Serverendpointexporter Serverendpointexporter () {return
        new Serverendpointexporter ();
    }

}

3. Specific implementation class You can choose your own URL or you want to take parameters

Package com.star.manager.service;
Import java.io.IOException;

Import Java.util.concurrent.CopyOnWriteArraySet;
Import Javax.websocket.OnClose;
Import Javax.websocket.OnError;
Import Javax.websocket.OnMessage;
Import Javax.websocket.OnOpen;
Import javax.websocket.Session;

Import Javax.websocket.server.ServerEndpoint;

Import lombok.extern.slf4j.Slf4j;
Import org.springframework.stereotype.Component; @Slf4j//@ServerEndpoint ("/websocket/{user}") @ServerEndpoint (value = "/websocket")@Componentpublic class Websocketserver {//static variable, used to record the current number of online connections.
    It should be designed to be thread-safe.
    private static int onlinecount = 0; The thread-safe set of the concurrent package, which holds the corresponding Mywebsocket object for each client. private static copyonwritearrayset<websocketserver> Websocketset = new Copyonwritearrayset<websocketserver

    > ();

    A connection session with a client, which needs to be sent to the client to send the data private sessions;
        /** * Connection to establish a successful call to the method * * @OnOpen public void OnOpen (Session sessions) {this.session = session;     Websocketset.add (this);           Add Addonlinecount () to the set; Online number plus 1 log.info ("There is a new join.")
        Current online number is "+ Getonlinecount ()");
        try {SendMessage ("Connection succeeded");
        catch (IOException e) {log.error ("WebSocket io exception"); }/////@OnOpen//public void OnOpen (@PathParam (' user ') String user, Session session) {//Currentus
	er = user; System.out.println ("Connected ...")
	"+ Session.getid ());  /** * Connection Shutdown method of call/@OnClose public void OnClose () {websocketset.remove (this);           Deletes the Subonlinecount () from the set; Number of online minus 1 log.info ("There is a connection closed.")
    Current online number is "+ Getonlinecount ()");
}
    /** * The method called after receiving the client message * * @param messages sent over message by the client * * @OnMessage public void OnMessage (String me

        Ssage, Session session) {Log.info ("messages from the client:" + message);
            Mass messages for (Websocketserver Item:websocketset) {try {item.sendmessage (message);
            catch (IOException e) {e.printstacktrace (); }}/** * * @param session * @param error/@OnError public void OnError
        , throwable error) {log.error ("error occurred");
    Error.printstacktrace ();


 }Public void SendMessage (String message) throws IOException {This.session.getBasicRemote (). SendText (Messag e); The/** * Group originates from the definition message */public static void Sendinfo (String message) throws IOException {Log.info (Me Ssage); for (Websocketserver Item:websocketset) {try {item.sendmessage (message); catch (IOException e) {continue; } } }public static synchronized int Getonlinecount () {return onlinecount;
    public static synchronized void Addonlinecount () {websocketserver.onlinecount++;
    public static synchronized void Subonlinecount () {websocketserver.onlinecount--; }
}

generate a message : There are a variety of message scenarios, HTTP (s), timed tasks, MQ, and so on, which is labeled with a HTTPQ requested controller code

	 @RequestMapping (value= "/pushvideolisttoweb", Method=requestmethod.post,consumes = "Application/json") Public
	 @ Responsebody map<string,object> pushvideolisttoweb (@RequestBody map<string,object> param) {
		 Map< string,object> result =new hashmap<string,object> ();
		 
		 try {
			 Websocketserver.sendinfo ("New Customer Inbound, Sltaccountid:" +commonutils.getvalue (param, "Sltaccountid"));
			 Result.put ("Operationresult", True);
		 } catch (IOException e) {
			 result.put ("Operationresult", True);
		 }
		 return result;
	 }

Important place I have been bold, mainly this paragraph, using this method, you can implement the server to push.

    public void SendMessage (String message) throws IOException {
        this.session.getBasicRemote (). SendText (message);
    

4.js (HTML will not write, just find a can trigger this JS can)

//socket = new WebSocket ("ws://localhost:9094/starmanager/websocket/John");
		var socket;
		if (typeof (WebSocket) = = "undefined") {Console.log ("Your browser does not support WebSocket");
			
			}else{console.log ("Your browser supports WebSocket"); Implements the WebSocket object, specifying the server address to connect to the port to establish a connection//socket = new WebSocket ("ws://localhost:9094/starmanager/websocket/John") 

			Socket = new WebSocket ("Ws://localhost:9094/starmanager/websocket");
			Open Event
			Socket.onopen = function () {
				Console.log ("Socket is open");
				Socket.send ("This is the message from the client" + Location.href + new Date ());
			Gets the message event
			socket.onmessage = function (msg) {
				console.log (msg.data);
				Find the message into the    background to get
				getcallinglist ();
			Shutdown Event
			socket.onclose = function () {
				console.log ("socket closed");
			An error event has occurred
			socket.onerror = function () {
				alert ("Error occurred with socket");
			}
			 $ (window). Unload (function () {
				  socket.close ();
				});                            		$ ("#btnSend"). Click (function () {
//                            			Socket.send ("This is the message from the client" + Location.href + new Date ());
//                            		});
//                            		$ ("#btnClose"). Click (function () {
//                            			socket.close ();
//                            		});
		}
                                

Simply put:

Through the front-end Code

Socket = new WebSocket ("Ws://localhost:9094/starmanager/websocket");

Where Starmanager is the project name,/webscoket is the access path name

Establishing a connection, the front-end call Scoket.open () causes the background to add an element to the static member variable Websocketset , which is equivalent to a cache . Background service Call SendMessage

(Specify a user, directed) or Sendinfo (Traverse websocketset to send, like a mass) method, you can push messages to the Logged-on client.

So much for the code. I'm going to run with these codes. Do when the page reported 404 error, if it is spring boot+h5, carefully check and I code there is no difference, plus the configuration path is OK, the problem should not be small.

If you happen to have a similar scenario that can be implemented with websocket, hopefully it will help you. If you have written incorrectly or not good enough, please correct me.