title: java ExecutorService, changing fixedsize
body: <p>So I want to change the fixedthreadpool size after already declaring it before, how would I go about doing this. I tried this but it doesn't work:</p>
  
  <pre><code> ExecutorService pool = Executors.newFixedThreadPool(3);
   //pool has 21 threads in queue 
  
   //do somestuff
  
   network sends a change in thread limit signal when there are 12 threads left in queue
   //redeclare:
        pool = Executors.newFixedThreadPool(4);
  </code></pre>
  
  <p>But it doesn't work, only 3 threads continue to be excuted at a time.</p>
  
  <p>I think I know what the problem is: the executor stores the 21 threads in queue and wont change the fixed thread pool size till the queue is cleared.
  I don't want this, How would I make it so that the change in threadpoolsize affects the entire queue? Would I need to reload the entire queue (if so, How would i do that)?</p>