JAVA

multi threading callable

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.*;
public class CallableDemo {
 
  public static class Counter implements Callable<String> {
        private int SIZE;
        private int counter = 0;
        private String name;
        public Counter(int size, String name) {
            this.SIZE = size;
            this.name = name;
        }
        @Override
        public String call() {
            while(this.counter < SIZE) {
                this.counter++;
            }
            return "Done " + this.name;
        }
  }
 
  public static void main(String args[]) throws Exception {
      int size = 1000000;
      ExecutorService pool = Executors.newFixedThreadPool(10);
      List<Future<String>> listOfFutures = new ArrayList<Future<String>>();
 
      for(int i=0; i<10; i++) {
          Callable<String> callableCounter = new Counter(size, "counter" + i);
          Future<String> futureCounterResult = pool.submit(callableCounter);
          listOfFutures.add(futureCounterResult);
      }
      for (Future<String> future : listOfFutures) {
          System.out.println(future.get());
      }
       
      pool.shutdown();
  }
}
Output: