如何使用Java中的Web套接字将消息发送到特定会话？

Question

以下是我的WebSockets客户端脚本。在这段代码中，我定义了一个带有IP地址和端口的WebSockets对象。

客户端脚本：

var webSocket =
new WebSocket('ws://localhost:8080/Spring4JSONHandling/websocket');
webSocket.onmessage = function processMessage(message)

{

var jsonData = JSON.parse(message.data);
        jsonforlogout = jsonData;
        //var user=JSON.parse(username.data);

        console.log(jsonData); //to print

        if (jsonData.message != null){
var msgAdd = JSON.stringify(jsonData.message);
        msgAdd = msgAdd.replace(/[&\/\\#,+()$~%.'"*?<>{}]/g, '');
        alert("3"+msgAdd);
        var xyz = msgAdd.split(" : ");
        var logged = '${me}';
        alert("logged" + logged);
        alert("xyz[0]" + xyz[0]);
        if (logged == xyz[0]){
           alert("1");
          $("#chat" + xyz[0]).chatbox("option", "boxManager").addMsg(xyz[0], xyz[1]);
} else{
        alert("2");
        $("#chat" + xyz[0]).chatbox("option", "boxManager").addMsg(xyz[0], xyz[1]);
}

}
/* if(jsonData.message=='close'){websocket.close();} */
if (jsonData.users != null)
{
document.getElementById("chatusers").innerHTML = "";
        var loggedInUser = '${me}';
        var i = 0;
        while (i < jsonData.users.length)
{
var onlineAdd = JSON.stringify(jsonData.users[i]);
        onlineAdd = onlineAdd.replace(/[&\/\\#,+()$~%.'":*?<>{}]/g, '');
        if (loggedInUser != onlineAdd){

var clone = "<a href='#' onclick=\"clickFun('" + onlineAdd.trim() + "');\" class='usr' data-chat-id='chat" + onlineAdd + "' data-chat-fname='" + onlineAdd + "' data-chat-lname='" + onlineAdd + "'"
        + " data-chat-status='online' data-chat-alertmsg='' data-chat-alertshow='true' data-rel='popover-hover' data-placement='right' data-html='true'"
        + " data-content=\"<div class='usr-card'>"
        + "<img src='Spring4JSONHandling/resources/img/1.png' alt='Jessica Dolof'>"
        + "<div class='usr-card-content'>"
        + "<h3>Jessica Dolof</h3>"
        + "<p>Sales Administrator</p>"
        + "</div>"
        + "</div>\"><i></i>" + onlineAdd + "</a>";
        $('#chatusers').append(clone);
}
i++;
}
}


//or(i = 0; i < responselist.data.length; i++) {
/* var i=0;
 while(i<jsonData.users.length) 
 {
 var comboitem = document.createElement("option"); 
 comboitem.text = jsonData.users[i];//"utsav";//
 comboitem.value = jsonData.users[i];//"10"; 
 usercombo.options.add(comboitem);
 i++;
 } */
}

function sendMessage(txt) {
//alert(messageText.value+ " h1");
webSocket.send(txt);
    // messageText.value = "";
}

window.onbeforeunload = function () {
webSocket.onclose = function() {};
    webSocket.close();
};

以下是服务器端点的代码。在这段代码中，我已经定义了一个带有服务器端点的WebSockets对象。

服务器代码：

package com.outbottle.controllers;
import java.io.IOException;
import java.io.StringWriter;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import javax.json.Json;
import javax.json.JsonArrayBuilder;
import javax.json.JsonObject;
import javax.json.JsonWriter;
import javax.servlet.http.HttpSession;
import javax.websocket.EndpointConfig;

import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint; 


@ServerEndpoint("/websocket")      
public class WebSocketTest {

    static Set<Session> chatroomUsers= Collections.synchronizedSet(new HashSet<Session>());

    private final static HashMap<String, WebSocketTest> sockets = new HashMap<>();

      private String myUniqueId;

        private String getMyUniqueId() {
            // unique ID from this class' hash code
            return Integer.toHexString(this.hashCode());
        }


    @OnOpen
    public void handleOpen(Session userSession) throws IOException {
        chatroomUsers.add(userSession);
                System.out.println("user added");                   //user added
            this.myUniqueId = this.getMyUniqueId();

                System.out.println("!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"+ myUniqueId);
                WebSocketTest.sockets.put(this.myUniqueId, this);
                System.out.println("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@"+sockets);
    }


    @OnMessage
    public void handleMessage(String message, Session userSession) throws IOException{  
        String username= (String) userSession.getUserProperties().get("username");
        Iterator<Session> itr=chatroomUsers.iterator(); 
        if(username==null){
            userSession.getUserProperties().put("username", message);
            userSession.getBasicRemote().sendText(buildJsonMessageData("System","You are now connected as  "+message));
        while (itr.hasNext()) (itr.next()).getBasicRemote().sendText(buildJsonUsersData());                     }
        else {

            while (itr.hasNext()) {
                itr.next().getBasicRemote().sendText(buildJsonMessageData(username,message));

            }
        }
    }

    @OnClose
    public void handleClose(Session userSession) throws IOException {
        // TODO Auto-generated method stub
        System.out.println("user logout");
        chatroomUsers.remove(userSession);
        Iterator<Session> itr = chatroomUsers.iterator();
        while (itr.hasNext()) (itr.next()).getBasicRemote().sendText(buildJsonUsersData());
    }

    private String buildJsonUsersData() {

        Iterator<String> itr= getUserNames().iterator();
        JsonArrayBuilder jsonArrayBuilder = Json.createArrayBuilder();

        while (itr.hasNext()) jsonArrayBuilder.add((String)itr.next());

         return Json.createObjectBuilder().add("users", jsonArrayBuilder).build().toString();

    }

private String buildJsonMessageData(String username, String message)
 {

    JsonObject jsonObject=Json.createObjectBuilder().add("message", username+" : "+ message).build();


    StringWriter stringWriter= new StringWriter();
    try (JsonWriter jsonWriter = Json.createWriter(stringWriter)){ 
        jsonWriter.write(jsonObject);
    }

    return stringWriter.toString(); 
}


private Set<String> getUserNames()
{
    HashSet<String> returnSet = new HashSet<String>();

    Iterator<Session> itr= chatroomUsers.iterator();
                                            System.out.println("@@@@@@@@@@@@@@@@@@@@@@"); 

    while (itr.hasNext()) 
    {
        returnSet.add(itr.next().getUserProperties().get("username").toString());
    }

        return returnSet;   
}

}

问题是当我在不同的IP上向用户发送消息时，所有具有相同名称的用户都会收到消息。我只需要将消息发送到特定会话。

Answer 1

看起来您正在遍历chatroomUsers函数中的所有会话handleMessage。

如果您只想将消息发送给特定用户/会话，那么您是否需要在此处检查username属性？