How to reuse a SSH (Jsch) session created in an AsyncTask in another class - session

Question

I'm a Android & Java newbie and here is my situation:
I'm trying to create an app which connects to a Beaglebone Black using a ssh connection and then controls some peripherals connected to the BBB by issuing commands coming from an Android device.
I'm opening (successfully) an ssh session in an AsyncTask while the user sees an splash screen, if the connection was successful the user will get a confirmation and then will be able to send predefined commands by clicking some available buttons.
What I want to do next is left the session opened and then create a new channel (exec or shell ) each time I wish to issue a command and wait for the response from the BBB, but I don´t know how to reuse such ssh session outside the AsynkTask.
is that even possible?
I'm using Android Studio 0.8.2 and Jsch 0.1.51, my code is as follows:
public class SplashScreen extends ActionBarActivity {
public static final int segundos =10;
public static final int milisegundos =segundos*1000;
public static final int delay=2;
private ProgressBar pbprogreso;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash_screen);
pbprogreso= (ProgressBar)findViewById(R.id.pbprogreso);
pbprogreso.setMax(maximo_progreso());
empezaranimacion();
}
public void empezaranimacion()
{
sshConnect task = new sshConnect();
task.execute(new String[] {"http:"});
new CountDownTimer(milisegundos,1000)
{
#Override
public void onTick(long milisUntilFinished){
pbprogreso.setProgress(establecer_progreso(milisUntilFinished));
}
#Override
public void onFinish(){
finish();
}
}.start();
}
public int establecer_progreso (long miliseconds)
{
return (int)((milisegundos-miliseconds)/1000);
}
public int maximo_progreso () {
return segundos-delay;
}
public class sshConnect extends AsyncTask <String, Void, String>{
ByteArrayOutputStream Baos=new ByteArrayOutputStream();
ByteArrayInputStream Bais = new ByteArrayInputStream(new byte[1000]);
#Override
protected String doInBackground(String... data) {
String host = "xxxxxxx";
String user = "root";
String pwd = "";
int port = 22;
JSch jsch = new JSch();
try {
Session session = jsch.getSession(user, host, port);
session.setPassword(pwd);
session.setConfig("StrictHostKeyChecking", "no");
session.connect();
ChannelExec channel = (ChannelExec)session.openChannel("exec");
channel.setOutputStream(Baos);
channel.setInputStream(Bais);
//Run Command
channel.setCommand("python ~/BBB_test/testconnect.py");
channel.connect();
try{Thread.sleep(3500);}catch (Exception ee){}
channel.disconnect();
//session.disconnect();
}catch (Exception e){
System.out.println(e.getMessage());
}
return Baos.toString();
}
#Override
protected void onPostExecute(String result) {
if (result.equals("Connected to BBB Baby!!\n")) {
Intent nuevofrom = new Intent(SplashScreen.this, Principal.class);
startActivity(nuevofrom);
finish();
} else {
Intent newfrom = new Intent(SplashScreen.this, ConnecError.class);
startActivity(newfrom);
finish();
}
}
}
//Here is where I want to reuse the opened session and create a new channel
public class sendCommand extends AsyncTask <String, Void, String >{
ByteArrayOutputStream Baosc=new ByteArrayOutputStream();
ByteArrayInputStream Baisc = new ByteArrayInputStream(new byte[1000])
protected String doInBackground (String... command){
try {
ChannelExec channel2 = (ChannelExec)session.openChannel("exec");
channel2.setOutputStream(Baosc);
channel2.setInputStream(Baisc);
//Run Command
channel2.setCommand("python ~/BBB_test/testgpio.py");
channel2.connect();
try{Thread.sleep(3500);}catch (Exception ee){}
channel2.disconnect();
}catch (Exception e) {
System.out.println(e.getMessage());
}
return Baosc.toString();
}
protected void onPostExecute(Long result) {
TextView txt = (TextView) findViewById(R.id.infotext);
txt.setText(result);
}
}
If something else is needed let me know! (it is the first time I ask something in a forum)
Thanks a lot for your time and support!

Answer 1

I managed to get what I wanted by using the recommendation from DamienKnight of creating the session outside the Asynktask class. I create a public classwith three methods to create, return and disconnect the session:
public static class cSession {
String host = "xxx.xxx.xxx.xxx";
String user = "root";
String pwd = "";
int port = 22;
JSch jsch = new JSch();
public Session Met1 (){
try {
session = jsch.getSession(user, host, port);
session.setPassword(pwd);
session.setConfig("StrictHostKeyChecking", "no");
} catch (Exception e2){
System.out.println(e2.getMessage());
}return session;
}
public Session damesession (){
return session;
}
public void close_ses(){
session.disconnect();
}
}
By doing this so, the creation of channels is flexible and I can use the methods from Jsch too.
public class sshConnect extends AsyncTask <String, Void, String>{
ByteArrayOutputStream Baos=new ByteArrayOutputStream();
ByteArrayInputStream Bais = new ByteArrayInputStream(new byte[1000]);
#Override
protected String doInBackground(String... data) {
cSession jschses = new cSession();
Session ses =null;
ses = jschses.Met1();
try {
ses.connect();
ChannelExec channel = (ChannelExec)ses.openChannel("exec");
channel.setOutputStream(Baos);
channel.setInputStream(Bais);
//Run Command
channel.setCommand("python ~/BBB_test/testconnect.py");
channel.connect();
try{Thread.sleep(3500);}catch (Exception ee){}
channel.disconnect();
//session.disconnect();
}catch (Exception e){
System.out.println(e.getMessage());
}
return Baos.toString();
}
Thanks #Damienknight!
Regards

Answer 2

If you are wanting to reuse the session, you dont need to reconect the channel each time. Connect it once as a shell, plugging an input and output stream into it. Use the streams to pass commands and capture output.
See the JSCH example on the JCraft website.
Channel channel=session.openChannel("shell");
channel.setInputStream(System.in);
channel.setOutputStream(System.out);
channel.connect();