java - 安卓 : Keep httpclient running in background and communicate with activity when message recieved by httpclient

Question

抱歉标题太长，但我不知道该怎么做。我正在开发一个 Android 项目，在该项目中我尝试使用名为 Cometd 的 PUSH 框架。 。现在Cometd使用Bayuex API/规范来实现PUSH服务。

当您考虑普通网站部分(用户登录或服务器端可扩展异步应用程序)时，Cometd 的工作效果简直棒极了，没有什么可提示的。我们面临的问题是在应用程序方面。没有可用的支持或文档。

经过一番努力，我能够编写代码在 Android 应用程序中使用 Cometd，不幸的是它有错误且不稳定。我将描述我如何构建它的结构，描述问题并显示代码。

有 2 个主要的 Activity 类:ConversationActivity 和 ChatMessagesActivity。在 ConversationActivity 中，我启动一个 httpclient 并通过执行握手连接到 PUSH 服务。

在同一个类中，有一个 ClientSessionChannel 监听器，它不断监听新消息。在 ConversationActivity 类中，我从服务器数据库中检索登录用户的所有对话。完成后，用户可以决定他/她想与谁聊天。

现在，当点击对话时，我会在另一个 Activity 中打开这两个用户的聊天消息。

现在，不要忘记每条新消息都会到达 ConversationActivity 中的 ClientSessionChannel Listener 中，这就是为什么我必须维护 ConversationActivity 和 ChatMessagesActivity 之间的通信链接的原因，这会导致各种不稳定。

现在，我想做的是将监听器和 httpclient 推送到另一个线程/类/背景等中。完成后，如何保持聊天消息之间的开放通信已打开，因此消息会更新。我希望问题已经清楚了。我现在将发布代码。请看一下:

public class ConversationActivity extends ApplicationDrawerLoader {

    static Context context;
List<PrivateChannel> privateChannelList = new ArrayList<>();

    List<Long> groupAccountList = new ArrayList<>();

    List<String> pushPrivateChannelList = new ArrayList<>();

    ListView conversationsList;

    ConversationAdapter conversationAdapter;

 protected static volatile BayeuxClient client;
    private ChatListener chatListener = new ChatListener();

    HttpClient httpClient = StaticRestTemplate.getHttpClient();

    String defaultURL = StaticRestTemplate.baseURL + "/cometd";

 @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_conversations);

        context = this;


        try {
            httpClient.start();
        } catch (Exception e) {
            e.printStackTrace();
        }

        if (isOnline()) {
            new getConversationsForLoggedInUser(this).execute();

            ClientTransport clientTransport = new LongPollingTransport(null, httpClient);
            client = new BayeuxClient(defaultURL, clientTransport);
            client.putCookie(new HttpCookie("JSESSIONID", StaticRestTemplate.getJsessionid()));
            client.getChannel(Channel.META_HANDSHAKE).addListener(new InitializerListener());
            client.getChannel(Channel.META_CONNECT).addListener(new ConnectionListener());
            client.handshake();
            boolean success = client.waitFor(2000, BayeuxClient.State.CONNECTED);
            if (!success) {
                Toast.makeText(getApplicationContext(), "Could not connect to PUSH service", Toast.LENGTH_LONG).show();
            }

 public class getConversationsForLoggedInUser extends AsyncTask<Void, Void, ResponseEntity<PrivateChannel[]>> {

client.getChannel("/person/"+privateChannel.getPrivateChannelName()).subscribe(chatListener);

// Here I get all conversations for user and load them in ListView using adapter
}
  public void sendMessageToChatActivity(final String channelName, final Map<String,Object> outputData) {
        // Here send the message to Chat activity.
        Log.d("Msg",String.valueOf(outputData.toString()));
        runOnUiThread(new Runnable() {
            public void run() {
                ChatMessagesActivity.recieveUpdatedMessage(channelName, outputData);
            }
        });
    }

    public static void recieveMessageFromChatActivity(String channelName, Map<String, Object> inputData){
        //client.putCookie(new HttpCookie("JSESSIONID", StaticRestTemplate.getJsessionid()));
        client.getChannel(channelName).publish(inputData);

    }

    private void initialize() {

    }

    private void connectionEstablished() {
        System.err.printf("system: Connection to Server Opened%n");

    }

    private void connectionClosed() {
        System.err.printf("system: Connection to Server Closed%n");
    }

    private void connectionBroken() {
        System.err.printf("system: Connection to Server Broken%n");
    }

    private class InitializerListener implements ClientSessionChannel.MessageListener {
        @Override
        public void onMessage(ClientSessionChannel channel, Message message) {
            if (message.isSuccessful()) {
                initialize();
            }
        }
    }

    private class ConnectionListener implements ClientSessionChannel.MessageListener {
        private boolean wasConnected;
        private boolean connected;

        public void onMessage(ClientSessionChannel channel, Message message) {
            if (client.isDisconnected()) {
                connected = false;
                connectionClosed();
                return;
            }
            wasConnected = connected;
            connected = message.isSuccessful();
            if (!wasConnected && connected) {
                connectionEstablished();
            } else if (wasConnected && !connected) {
                connectionBroken();
            }
        }
    }

// THe below method sends message to the ChatMessagesActivity.
   public class ChatListener implements ClientSessionChannel.MessageListener {
        public void onMessage(ClientSessionChannel channel, Message message) {
            sendMessageToChatActivity(channel.toString(),message);
        }
    }

聊天消息 Activity :

public class ChatMessagesActivity extends ApplicationDrawerLoader {
    Context context;

    public ListView chatList;

    protected static ChatMessagesAdapter chatMessagesAdapter = null;
 @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_chat_messages);

        chatList = (ListView) findViewById(R.id.chatList);
        context = this;

 sendMessageButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
// Here I send message to ConversationActivity, which in turn sends it via CometdD.
                    sendMessageToConversationsActivity("/service/person/" + String.valueOf(conversationId), outputData);
}


    public static void recieveUpdatedMessage(String channelName, Map<String, Object> input) {

// Here I recieve the new message and add it to adapter. 
                    HashMap<String, String> insertMap = new HashMap<>();
// Add data to hashmap and add it to adapter 
 chatMessagesAdapter.add(insertMap);
                    chatMessagesAdapter.notifyDataSetChanged();
}
 public void sendMessageToConversationsActivity(String channelName, Map<String, Object> output) {
        ConversationActivity.recieveMessageFromChatActivity(channelName, output);
    }

    public class getPrivateChatsForUser extends AsyncTask<Void, Void, ResponseEntity<RestReplies[]>> {

        ChatMessagesActivity chatMessagesActivity = null;

        getPrivateChatsForUser(ChatMessagesActivity chatMessagesActivity) {
            this.chatMessagesActivity = chatMessagesActivity;

        }
// Here i get chat messages from network and load it in list-view using adapter.,


    public class ChatMessagesAdapter extends BaseAdapter {

// Adapter code to display, nothing fancy. 
}
}

我知道代码看起来有点长，但问题也是如此。我将不胜感激任何帮助。我不是 Android 专家，只是尝试集成它。谢谢。 :-)

编辑

public class CometdService extends Service {

    protected static volatile BayeuxClient client;

    String defaultURL = StaticRestTemplate.baseURL + "/cometd";


    HttpClient httpClient = StaticRestTemplate.getHttpClient();

    private ChatListener chatListener = new ChatListener();


    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }


    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        try {
            httpClient.start();
        } catch (Exception e) {
            e.printStackTrace();
        }


        ClientTransport clientTransport = new LongPollingTransport(null, httpClient);
        client = new BayeuxClient(defaultURL, clientTransport);
        client.putCookie(new HttpCookie("JSESSIONID", StaticRestTemplate.getJsessionid()));
        client.getChannel(Channel.META_HANDSHAKE).addListener(new InitializerListener());
        client.getChannel(Channel.META_CONNECT).addListener(new ConnectionListener());
        client.handshake();
        boolean success = client.waitFor(2000, BayeuxClient.State.CONNECTED);
        if (!success) {
            Toast.makeText(getApplicationContext(), "Could not connect to PUSH service", Toast.LENGTH_LONG).show();
        }


        return Service.START_REDELIVER_INTENT;
    }

    @Override
    public void onDestroy() {

    }

    private class InitializerListener implements ClientSessionChannel.MessageListener {
        @Override
        public void onMessage(ClientSessionChannel channel, Message message) {
            if (message.isSuccessful()) {
                initialize();
            }
        }
    }

    private class ConnectionListener implements ClientSessionChannel.MessageListener {
        private boolean wasConnected;
        private boolean connected;

        public void onMessage(ClientSessionChannel channel, Message message) {
            if (client.isDisconnected()) {
                connected = false;
                connectionClosed();
                return;
            }
            wasConnected = connected;
            connected = message.isSuccessful();
            if (!wasConnected && connected) {
                connectionEstablished();
            } else if (wasConnected && !connected) {
                connectionBroken();
            }
        }
    }

    private void initialize() {

    }

    private void connectionEstablished() {
        System.err.printf("system: Connection to Server Opened%n");

    }

    private void connectionClosed() {
        System.err.printf("system: Connection to Server Closed%n");
    }

    private void connectionBroken() {
        System.err.printf("system: Connection to Server Broken%n");
    }

    public class ChatListener implements ClientSessionChannel.MessageListener {
        public void onMessage(ClientSessionChannel channel, Message message) {
           // sendMessageToChatActivity(channel.toString(), message);
        }
    }
}

新创建的服务，正在进行中。

Answer 1

看起来像 IntentService可能有助于与服务器的通信。