------------MainActivity.java-------------

package com.example.demyon.opengatefinal;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;

import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.fail;

public class MainActivity extends AppCompatActivity {

    static final String command ="./gate.sh";
    static final String userName= "pi";
    static final String password= "1234";
    static final String connectionIP= "192.168.1.4";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);



        Button openBtn = (Button) findViewById(R.id.openBtn);



        openBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Log.v("Tag","Erro numero 1");
                Log.v("Tag",userName+" "+password+" "+connectionIP);
                SSHManager instance = new SSHManager(userName, password, connectionIP, "");
                Log.v("Tag","Erro numero 2");
                String errorMessage = instance.connect();
                Log.v("Tag","Erro numero 3");
                if(errorMessage != null)
                {
                    Log.v("Tag","Erro dentro do IF");
                    System.out.println(errorMessage);
                    fail();
                }
                Log.v("Tag","Erro numero 4");
                String expResult = "";
                // call sendCommand for each command and the output
                //(without prompts) is returned
                String result = instance.sendCommand(command);
                // close only after all commands are sent
                instance.close();
                assertEquals(expResult, result);
                Log.v("Tag","Erro Final");
            }
        });

    }
}



--------------SSHManager.java-----------

package com.example.demyon.opengatefinal;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;

import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Created by Demyon on 10/15/2017.
 */

public class SSHManager {
    private static final Logger LOGGER =
            Logger.getLogger(SSHManager.class.getName());
    private JSch jschSSHChannel;
    private String strUserName;
    private String strConnectionIP;
    private int intConnectionPort;
    private String strPassword;
    private Session sesConnection;;
    private int intTimeOut;

    private void doCommonConstructorActions(String userName,
                                            String password, String connectionIP, String knownHostsFileName)
    {
        jschSSHChannel = new JSch();

        try
        {
            jschSSHChannel.setKnownHosts(knownHostsFileName);
        }
        catch(JSchException jschX)
        {
            logError(jschX.getMessage());
        }

        strUserName = userName;
        strPassword = password;
        strConnectionIP = connectionIP;
    }

    public SSHManager(String userName, String password,
                      String connectionIP, String knownHostsFileName)
    {
        doCommonConstructorActions(userName, password,
                connectionIP, knownHostsFileName);
        intConnectionPort = 22;
        intTimeOut = 60000;
    }

    public SSHManager(String userName, String password, String connectionIP,
                      String knownHostsFileName, int connectionPort)
    {
        doCommonConstructorActions(userName, password, connectionIP,
                knownHostsFileName);
        intConnectionPort = connectionPort;
        intTimeOut = 60000;
    }

    public SSHManager(String userName, String password, String connectionIP,
                      String knownHostsFileName, int connectionPort, int timeOutMilliseconds)
    {
        doCommonConstructorActions(userName, password, connectionIP,
                knownHostsFileName);
        intConnectionPort = connectionPort;
        intTimeOut = timeOutMilliseconds;
    }

    public String connect()
    {
        String errorMessage = null;

        try
        {
            sesConnection = jschSSHChannel.getSession(strUserName,
                    strConnectionIP, intConnectionPort);
            sesConnection.setPassword(strPassword);
            // UNCOMMENT THIS FOR TESTING PURPOSES, BUT DO NOT USE IN PRODUCTION
            // sesConnection.setConfig("StrictHostKeyChecking", "no");
            sesConnection.connect(intTimeOut);
        }
        catch(JSchException jschX)
        {
            errorMessage = jschX.getMessage();
        }

        return errorMessage;
    }

    private String logError(String errorMessage)
    {
        if(errorMessage != null)
        {
            LOGGER.log(Level.SEVERE, "{0}:{1} - {2}",
                    new Object[]{strConnectionIP, intConnectionPort, errorMessage});
        }

        return errorMessage;
    }

    private String logWarning(String warnMessage)
    {
        if(warnMessage != null)
        {
            LOGGER.log(Level.WARNING, "{0}:{1} - {2}",
                    new Object[]{strConnectionIP, intConnectionPort, warnMessage});
        }

        return warnMessage;
    }

    public String sendCommand(String command)
    {
        StringBuilder outputBuffer = new StringBuilder();

        try
        {
            Channel channel = sesConnection.openChannel("exec");
            ((ChannelExec)channel).setCommand(command);
            InputStream commandOutput = channel.getInputStream();
            channel.connect();
            int readByte = commandOutput.read();

            while(readByte != 0xffffffff)
            {
                outputBuffer.append((char)readByte);
                readByte = commandOutput.read();
            }

            channel.disconnect();
        }
        catch(IOException ioX)
        {
            logWarning(ioX.getMessage());
            return null;
        }
        catch(JSchException jschX)
        {
            logWarning(jschX.getMessage());
            return null;
        }

        return outputBuffer.toString();
    }

    public void close()
    {
        sesConnection.disconnect();
    }

}