用websocket制作android聊天模块

Question

我想在android应用程序上做一个聊天模块。用户和管理员可以进行简单的聊天，以便进行交流。使用节点js的服务器。客户端使用java-WebSocket-client。

首先，我在节点js上创建了web socket服务器。

const Messages = require('./models/index').Messages;
const WebSocketServer = require("ws").Server;

module.exports = (server) => {
    const wss = new WebSocketServer({server: server});

    wss.on("connection", function (ws) {

    console.info("websocket connection open");

    ws.on("join", function (userId) {
        console.log(userId +" : has joined the chat "  );

        Messages.findAll({
          attributes: ['message', 'roomId', 'senderId','createdAt'],
          where: { roomId: userId },
          order: [ ['createdAt', 'ASC'] ]
        }).then(message => {
          ws.send('get_last_messages', message);
        });
    });

    ws.on('message', (data) => {  
    console.log("websocket received a message");
    console.log(data);

    ws.on("close", function () {
        console.log("websocket connection close");
    });
});
console.log("websocket server created");

Android chatActivity (实现"org.java-websocket:Java-WebSocket:1.3.9")：

public class MainActivity extends Activity {
    private WebSocketClient mWebSocketClient;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        connectWebSocket();
    }
private void connectWebSocket() {
        URI uri;
        try {
            uri = new URI("ws://websockethost:8080");
        } catch (URISyntaxException e) {
            e.printStackTrace();
            return;
        }

        mWebSocketClient = new WebSocketClient(uri) {
            @Override
            public void onOpen(ServerHandshake serverHandshake) {
                Log.i("Websocket", "Opened");
                mWebSocketClient.send("Hello from " + Build.MANUFACTURER + " " + Build.MODEL);
            }

            @Override
            public void onMessage(String s) {
                final String message = s;
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        TextView textView = (TextView)findViewById(R.id.messages);
                        textView.setText(textView.getText() + "\n" + message);
                    }
                });
            }

            @Override
            public void onClose(int i, String s, boolean b) {
                Log.i("Websocket", "Closed " + s);
            }

            @Override
            public void onError(Exception e) {
                Log.i("Websocket", "Error " + e.getMessage());
            }
        };
        mWebSocketClient.connect();
    }

    public void sendMessage(View view) {
        EditText editText = (EditText)findViewById(R.id.message);
        mWebSocketClient.send(editText.getText().toString());
        editText.setText("");
}

但它不起作用。连接已关闭。

如何正确创建nodejs websocket服务器和android websocketclient？

Answer 1

您需要在AndroidManifest.xml中添加internet权限，看起来您可以在MainThread上进行网络通信。

https://developer.android.com/training/basics/network-ops/connecting