Question

Well I am not familiar with threads in java, so I am dealing with this problem: I have a singleton object who contains some objects (let say sessions) and each object has a duration time, so that means that after a some time one object is considered expired so it needs to be removed from (a pool – List in singleton) singleton. To do this I decided to have a thread that checks every 5 minutes (or 10 minutes or whatever) and clean up all session in the singleton class. How can I implement such a functionality avoiding any possible deadlock and or time consuming blocks. Thank you in advance.

Answer 1

Runnable cleaner = new Runnable() {
public void run() { /* remove expired objects here */ 
     //Using get method check whether object is expired 
   }
};
Executors.newScheduledThreadPool(1)
       .scheduleWithFixedDelay(cleaner, 0, 30, TimeUnit.SECONDS);