Record the ThreadPoolExecutor main thread waiting for sub threads

In the use of ThreadPoolExecutor There was a problem starting the thread pool ： Cannot have the main thread wait for the child thread to complete before continuing .

I found many methods on the Internet, such as :
while Loop polling
Thread Class join Method
synchronized lock
CountDownLatch
Future
BlockingQueue
CyclicBarrier
LockSupport

Finally, it is found that none of them apply to ThreadPoolExecutor.

It took a long time to solve it .

The case is as follows

package com.siger;

import com.google.common.util.concurrent.ThreadFactoryBuilder;

import java.util.concurrent.*;

/** * @author zwh * @date 2022/2/16 */
public class threadTest {
    
    static class MyRunable implements Runnable {
    

        @Override
        public void run() {
    
            System.out.println("-------" + Thread.currentThread().getName() + " Operating -----------");
            try {
    
                Thread.sleep(100);
            } catch (InterruptedException e) {
    
                e.printStackTrace();
            }
        }
    }


    public static void main(String[] args) throws InterruptedException {
    
        long startTime = System.currentTimeMillis();
        System.out.println("-------" + Thread.currentThread().getName() + " Operating -----------");
        for (int i = 0; i < 100; i++) {
    
            System.out.print(i + "\t");
        }

        ThreadFactory threadFactory = new ThreadFactoryBuilder().setNameFormat("thread-call-runner-%d").build();
        ThreadPoolExecutor executor = new ThreadPoolExecutor(8, 8 + 2, 500L, TimeUnit.MICROSECONDS, new LinkedBlockingDeque<>(), threadFactory);


        for (int i = 0; i < 20; i++) {
    
        //******* Key points of the problem ******
            Future<?> future = executor.submit(new MyRunable());
            try {
    
                future.get();
            } catch (ExecutionException e) {
    
                e.printStackTrace();
            }
        }

        executor.shutdown();
        System.out.println("-------" + Thread.currentThread().getName() + " Operating -----------");
        for (int i = 200; i < 400; i++) {
    
            System.out.print(i + "\t");
        }
        long endTime = System.currentTimeMillis();
        long usedTime = (endTime - startTime) / 1000;
        System.out.println("----------- Total time taken " + usedTime + "-------------");


    }
}

The above is my plan , The test was successfully completed .

If any big man has a better way , Please give me some advice .

The previous methods are not applicable ThreadPoolExecutor, Although this creation method is good , Not easy to appear OOM, Maybe I'm not used to it , Still need to study more .

About ThreadPoolExecutor For other questions, see another article
Alibaba tips ： Creating threads manually works better