JUC thread scheduling

package org.meng.juc;

import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
 
/*
 *  One 、 Thread pool ： Provides a thread queue , The queue holds all waiting threads . Avoid the creation and destruction of additional costs , Improved response speed .
 * 
 *  Two 、 The architecture of thread pool ：
 * 	java.util.concurrent.Executor :  Root interface responsible for thread usage and scheduling 
 * 		|--**ExecutorService  A subinterface :  Main interface of thread pool 
 * 			|--ThreadPoolExecutor  Implementation class of thread pool 
 * 			|--ScheduledExecutorService  A subinterface ： Responsible for the scheduling of threads 
 * 				|--ScheduledThreadPoolExecutor ： Inherit  ThreadPoolExecutor,  Realization  ScheduledExecutorService
 * 
 *  3、 ... and 、 Tool class  : Executors 
 * ExecutorService newFixedThreadPool() :  Create a fixed-size thread pool 
 * ExecutorService newCachedThreadPool() :  Cache thread pool , The number of thread pools is not fixed , The quantity can be changed automatically according to the demand .
 * ExecutorService newSingleThreadExecutor() :  Create a single thread pool . There is only one thread in the thread pool 
 * 
 * ScheduledExecutorService newScheduledThreadPool() :  Create a fixed size thread , Tasks can be executed late or on a regular basis .
 */
public class TestScheduledThreadPool {
 
	public static void main(String[] args) throws Exception {
		ScheduledExecutorService pool = Executors.newScheduledThreadPool(5);
		
		for (int i = 0; i < 5; i++) {
			Future<Integer> result = pool.schedule(new Callable<Integer>(){
 
				@Override
				public Integer call() throws Exception {
					int num = new Random().nextInt(100);// Generate random number 
					System.out.println(Thread.currentThread().getName() + " : " + num);
					return num;
				}
				
			}, 1, TimeUnit.SECONDS);
			
			System.out.println(result.get());
		}
		
		pool.shutdown();
	}
	
}