如何使用Microsoft Java-Client接收SignalR广播消息？

Question

我需要将消息从ASP.NET服务器推送到Android设备,以便在记录状态发生变化时发出通知.所以我想使用来自GitHub的新的Microsoft SignalR Java-Client,使用Eclipse与Android ADT Bundle和Java.

• https://github.com/SignalR/java-client
• http://whathecode.wordpress.com/2014/03/20/getting-started-with-the-java-signalr-sdk/

我是Java和SignalR的新手.我有使用HTML工作的SignalR Hub和JavaScript客户端,它可以发送和接收消息.但是我无法进入下一步并让Java-Client在Eclipse/Java/Android中运行.我不知道如何注册接收广播消息.当我使用HTML/JavaScript页面发送消息时,我没有在Android应用程序中,在模拟器中,在Eclipse中收到消息.我能够

我有以下ASP.NET SignalR Hub.cs文件设置:

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using Microsoft.AspNet.SignalR;
    using Microsoft.AspNet.SignalR.Hubs;
    using System.Threading.Tasks;

    public class PtThroughputHub : Hub
    {
        public void SendAll(string message)
        {
            Clients.All.broadcastMessage(message);
        }
        public void SendGroup(string groupName, string message)
        {
            Clients.Group(groupName).broadcastMessage(message);
        }
        public Task JoinGroup(string groupName)
        {
            return Groups.Add(Context.ConnectionId, groupName);
        }
        public Task LeaveGroup(string groupName)
        {
            return Groups.Remove(Context.ConnectionId, groupName);
        }
    }

在JavaScript中,我还可以使用从ASP.NET Hub.cs自动生成的Hubs.js文件来通过Hub发送和接收消息.

<script src="Scripts/jquery-2.1.0.min.js"></script>
<!--Reference the SignalR library. -->
<script src="Scripts/jquery.signalR-2.0.3.min.js"></script>
<!--Reference the autogenerated SignalR hub script. -->
<script src="signalr/hubs"></script>    

$(function () {
    $.connection.hub.logging = true;

    // Declare a proxy to reference the hub.
    var ptThroughput = $.connection.ptThroughputHub;
    // Create a function that the hub can call to broadcast messages.
    ptThroughput.client.broadcastMessage = function (message) {
        alert(message);
    };

    // Start the connection.
    $.connection.hub.start()
        .done(function () {
                    alert('Successfully connected as ' + $.connection.hub.id);
                    ptThroughput.server.joinGroup("Group1");
                    $('#btnSend').click(function () {
                        // Call the Send method on the hub.
                        ptThroughput.server.sendGroup('Group1', 'My Message Test Here!');                        
                    })
                })
                .fail(function () { $("#connection").text('Can not connect to SignalR hub!'); });

});

但是,在Eclipse/Java/Android中,我不确定需要使用哪些代码来接收广播消息.我能够启动连接并在以下代码示例的末尾接收connectionID但我被困在那里.我是否需要以某种方式使用.on()或.subscribe()？当我运行此代码时,我看到记录了连接ID,但我无法从html/JavaScript页面触发广播消息.没有收到任何东西,我不会在任何地方收到错误.有谁知道我在这里可能会缺少什么？

import microsoft.aspnet.signalr.client.SignalRFuture;
import microsoft.aspnet.signalr.client.hubs.HubConnection;
import microsoft.aspnet.signalr.client.hubs.HubProxy;
import microsoft.aspnet.signalr.client.hubs.SubscriptionHandler;

//Setup connection
String server = "http://Servername/Applications/ThroughputMobile/";
HubConnection connection = new HubConnection(server);
HubProxy proxy = connection.createHubProxy("ptThroughputHub");


//--HERE IS WHERE I AM NOT SURE HOW TO SET IT UP TO RECEIVE A NOTIFICATION---
//Setup to receive broadcast message
proxy.on("broadcastMessage",new SubscriptionHandler() {         
    @Override
    public void run() { 
        Log.i("Test Message", "broadcastMessage received..."); 
    }
});
//---------------------------------------------------------------------------

//Start connection
SignalRFuture<Void> awaitConnection = connection.start();
try {
    awaitConnection.get();
} catch (InterruptedException e) {

//Log Connection ID
Log.i("Test Message", "Connection ID = " + connection.getConnectionId());

那么,我是否再次使用proxy.on()来设置接收广播通知或其他内容？我传递给方法的字符串是什么？在我的情况下,"broadcastMessage"或者也许是"sendAll"？任何帮助将不胜感激.

Answer 1

我没有JoinGroup()从SignalR问题中显示的Hub中调用该方法.您需要加入Hub才能接收广播是有道理的.所以在我的后台服务中onStart(),我打电话invoke("JoinGroup", "Group1").然后我调用on()方法来设置收到的消息的处理程序. Group1是一个可配置的组名,集线器使用该名称来拆分广播,以便不同的组可以使用同一个集线器.请参阅下面的完整代码和注释解决方案块.希望这能节省一些时间!

以下是帮助我完成Android后台服务代码的原因:

//Invoke JoinGroup to start receiving broadcast messages            
proxy.invoke("JoinGroup", "Group1");

//Then call on() to handle the messages when they are received.        
proxy.on( "broadcastMessage", new SubscriptionHandler1<String>() 
{
  @Override
  public void run(String msg) {
      Log.d("result := ", msg);                 
  }
}, String.class);

以下是完整的Android后台服务代码:

import java.util.concurrent.ExecutionException;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.IBinder;
import android.widget.Toast;
import microsoft.aspnet.signalr.client.*;
import microsoft.aspnet.signalr.client.hubs.*;

public class NotifyService extends Service {

    @Override
    public void onCreate() {
        super.onCreate();       
    }

    @SuppressWarnings("deprecation")
    @Override
    public void onStart(Intent intent, int startId) {      
            super.onStart(intent, startId);       
            Toast.makeText(this, "Service Start", Toast.LENGTH_LONG).show();       

        String server = "http://Servername/Applications/ThroughputMobile/";
            HubConnection connection = new HubConnection(server);
            HubProxy proxy = connection.createHubProxy("ptThroughputHub");

            SignalRFuture<Void> awaitConnection = connection.start();
            try {
                awaitConnection.get();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (ExecutionException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }          

        //--HERE IS MY SOLUTION-----------------------------------------------------------
        //Invoke JoinGroup to start receiving broadcast messages            
        proxy.invoke("JoinGroup", "Group1");

        //Then call on() to handle the messages when they are received.        
            proxy.on( "broadcastMessage", new SubscriptionHandler1<String>() {
                @Override
                public void run(String msg) {
                    Log.d("result := ", msg);                   
                }
            }, String.class);

        //--------------------------------------------------------------------------------
    }
    @Override
    public void onDestroy() {
       super.onDestroy();       
    }   
    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }
}