我有一个名为conexao的类，它管理我到服务器的socket.io连接，我意识到我在一些活动中需要它。
把它定为一节课有错吗？
conexao.java文件：

package com.example.group;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;
import io.socket.client.IO;
import io.socket.client.Socket;
public class Conexao  {
    private static Conexao instance;
    public  String host = "http://192.168.0.117:8090";
    Socket socket;
    public synchronized static Conexao getInstance() {
        if (instance == null) {
            try {
                instance = new Conexao();
            }catch (Exception e){
            }
        }
        return instance;
    }
    public Conexao() throws URISyntaxException {
        socket = IO.socket(host);
    }
    public void open(){
        socket.connect();
    }
    public void close(){
        socket.disconnect();
    }
}