package inverview.callable;

import java.util.ArrayList;

import java.util.Date;

import java.util.List;

import java.util.concurrent.Callable;

import java.util.concurrent.ExecutionException;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Future;

public class MyCallable implements Callable<String> {

@Override

public String call() throws Exception {

Thread.sleep(1000);

// return the thread name executing this callable task

return Thread.currentThread().getName();

}

public static void main(String args[]) {

// Get ExecutorService from Executors utility class, thread pool size is 10

ExecutorService executor = Executors.newFixedThreadPool(10);

// create a list to hold the Future object associated with Callable

List<Future<String>> list = new ArrayList<Future<String>>();

// Create MyCallable instance

Callable<String> callable = new MyCallable();

for (int i = 0; i < 100; i++) {

// submit Callable tasks to be executed by thread pool

Future<String> future = executor.submit(callable);

// add Future to the list, we can get return value using Future

list.add(future);

}

for (Future<String> fut : list) {

try {

// print the return value of Future, notice the output delay in console

// because Future.get() waits for task to get completed

System.out.println(new Date() + "::" + fut.get());

} catch (InterruptedException | ExecutionException e) {

e.printStackTrace();

}

}

// shut down the executor service now

executor.shutdown();

}

}