One connection for multiple object

I'am running into trouble implementing a proper code. I have several objects that use a ssh tunnel and I don't want to close and open a new connection each time. So I implemented singleton pattern to get the instance of my connection and I pass it to each object. After readings It seems that singleton pattern aren't a proper way to code, but I don't see any other way recoding my classes.

Instance class :

public class ServerConnection {

String ip = "localhost";
String user = "tom1";
String pass = "1";
int port = 22;
private static Session session;

private ServerConnection() throws JSchException {
    try {
        JSch jsch = new JSch();
        session = jsch.getSession(user, ip, port);
        session.setPassword(pass);
        java.util.Properties config = new java.util.Properties();
        config.put("StrictHostKeyChecking", "no");
        session.setConfig(config);
        session.connect();
    }catch(Exception e){
        System.out.println(e);
    }

}

public static Session getInstance() throws JSchException {
    if (session == null) {
        System.out.println("Creation de la connection");
        new ServerConnection();
    }else{
        System.out.println("La connection existe deja");
    }
    return session;
}

}

My objects :

public class EchoText implements InterfaceScript
{

/**
*Message to display with the Echo.
*/
String message;

/**
* Params of the test.
*/
String params;

/**
*Result of the test.
*/
String result="Failed";

/**
*Constructor of EchoText.
*/
public void EchoText (){ 
}

@Override
public String run(String params) {
    this.params=params;
    treatParameters();
    Session session;
    try {
        //Verify if an instance of the server is running.
        session = ServerConnection.getInstance();

        //Open a channel to send informations
        ChannelExec channel = (ChannelExec) session.openChannel("exec");
        BufferedReader in = new BufferedReader(new InputStreamReader(channel.getInputStream()));

        //Set the command to send
        channel.setCommand("cmd /c echo "+this.message);
        channel.connect();

    // Read the outptut
    String msg = null;
    while ((msg = in.readLine()) != null) {
        System.out.println(msg);
    }

    channel.disconnect();
    this.result();
    return this.result;
    } catch (JSchException | IOException e)
    {
        System.out.println(e);
        return this.result;
    }
}   
}