Worker Thread in Java

Question

I need to read the data from a table every minute through thread & then perform certain action.

Should I just start a thread & put it in sleep mode for 1 minute, once the task is done. And then again check if the table has any data, perform the task again & go to sleep for 1 minute...

Is this the right approach? Can any one provide me some sample code in Java for doing the same?

Thanks!

Answer 1

"Should I just start a thread & put it in sleep mode for 1 minute" Even if you want you want to go with traditional thread ( dont want to use executor Fremework) DO NOT USE SLEEP for waiting purpose as it will not release lock and its a blocking operation . DO USE wait(timeout) here.

Wrong Approach -

public synchronized void doSomething(long time)  throws InterruptedException {
  // ...
  Thread.sleep(time);
}

Correct Approach

public synchronized void doSomething(long timeout) throws InterruptedException {
// ...
  while (<condition does not hold>) {
    wait(timeout); // Immediately releases the current monitor
  }
}

you may want to check link https://www.securecoding.cert.org/confluence/display/java/LCK09-J.+Do+not+perform+operations+that+can+block+while+holding+a+lock