Android-使用多个线程执行不同的功能

Question

I am pretty new to Android programming but got some experience in other languages. I want to create an APP which is principle working like this.

1. The APP is a process which is asking my Web-/Database-Server every 10 seconds if there is an event to execute.

2. The Web-/Database-Server answers with an event id or even a function name.

3. The APP opens a new thread which executes the event with the id or even better directly the function name.

My Questions are:

1. Is this perfomant? Or can this chrash pretty easily?
2. Is it limited to 2 threads within the process or can I even open every time a new thread for the function which I want to execute? Maybe because of the other function is still running?

3. How can I execute a function with the return value? For example

   InputStream in = response.getEntity().getContent(); //Get the data in the entity

   public in(void) { // execute a function which got´s the same name as the variable "in" }

The result should be: The one thread is asking every 10 seconds my Web-/Database-Server if there is an event. The event gets executed within a thread and this is working parallel (at the same time without crashing or even getting stucked).

Sample Code of these Threads would be appreciated.

My code till yet:

public class service extends Service { private static final String TAG = "MyService";

 @Override public IBinder onBind(Intent intent) { return null; } public void onDestroy() { Toast.makeText(this, "My Service Stopped", Toast.LENGTH_LONG).show(); Log.d(TAG, "onDestroy"); } @Override public int onStartCommand(Intent intent, int flags, int startid) { Toast.makeText(this, "My Service Started", Toast.LENGTH_LONG).show(); Log.d(TAG, "onStart"); Thread thread = new Thread(new Runnable() { @Override public void run() { new Timer().scheduleAtFixedRate(new TimerTask() { @Override public void run() { System.out.println("Send GO!"); Device dev = new Device(); dev.getDeviceId(getBaseContext()); dev.getEmail(getBaseContext()); dev.sendDeviceItems(); } }, 0, 10000);//put here time 1000 milliseconds=1 second } }); thread.start(); return Service.START_STICKY; } } 

Answer 1

1. Is this perfomant? Or can this chrash pretty easily?
   • Yes it will be performance hit. Asking for api every 10sec will drain your battery also.
   • With proper exception handling it won't crash pretty easily.

Is it limited to 2 threads within the process or can I even open every time a new thread for the function which I want to execute? Maybe because of the other function is still running?

• You can run as many threads you want but it will be difficult to maintain code in that
  case . You can use VOLLY or OKHTTP for network related things they will handle you thread part also.

How can I execute a function with the return value? For example

InputStream in = response.getEntity().getContent(); //Get the data in the entity

public in(void) { // execute a function which got´s the same name as the variable "in" }

• For calling method at run time with Method name you can just use of REFLECTION in java. This will fulfil your need.