public class MainActivity extends AppCompatActivity {
private static final String url ="jdbc:mysql://localhost:3306/mydbtest?characterEncoding=UTF-8&useSSL=false";
private static final String username ="root";
private static final String password ="root";
public Connection connection;
final String LOG_TAG = "myLogs";
Potok mPotok =new Potok();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    mPotok.run();
}
private class Potok implements Runnable{
    public void run(){
        try{
            connection = DriverManager.getConnection(url,username,password);
            Log.d(LOG_TAG, "Vse ok potok idet ");
        }catch (Exception e){
            Log.d(LOG_TAG, "Oshibka potoka ");
            e.printStackTrace();
        }
    }
}