Android App still remain active without any activity

Question

I'm developing an Android App in Java. I used a lot of library: firebase crashlytics, SQLCipher, ButterKnife etc.. The problem is: when I run the app from Android Studio, I notice the app still remain active as process, even if I close all activities. I know that there are some thread that works on background.. but I don't know how to check which thread is active, and more important, what does it do. Any idea about?

Answer 1

You can get what state a thread is in by using the getState() method which returns an Enum of Thread.States. A thread can only be in one of the following states at a given point in time.

NEW A Fresh thread that has not yet started to execute.
RUNNABLE A thread that is executing in the Java virtual machine.
BLOCKED A thread that is blocked waiting for a monitor lock.
WAITING A thread that is wating to be notified by another thread.
TIMED_WAITING A thread that is wating to be notified by another thread for a specific amount of time.
TERMINATED A thread whos run method has ended.

Thread t = new Thread();
Thread.State e = t.getState();
Thread.State[] ts = e.values(); 
for(int i = 0; i < ts.length; i++){
   System.out.println(ts[i]); 
}   

Answer 2

To kill the thread , u can do this :

myService.getThread().interrupt();

NOTE : the method Thread.stop() is deprecated

EDIT : : try this

public void stopThread(){
  if(myService.getThread()!=null){
      myService.getThread().interrupt();
      myService.setThread(null);
  }
}