package com.somitsolutions.training.java.ExperimentationWithFutureTask;

public class ProductInfo {
    private String productName;
    private float productPrice;

    public ProductInfo(String productName, float productPrice) {
        this.productName = productName;
        this.productPrice = productPrice;
    }

    public String getProductName() {
        return productName;
    }

    public void setProductName(String productName) {
        this.productName = productName;
    }

    public float getProductPrice() {
        return productPrice;
    }

    public void setProductPrice(float productPrice) {
        this.productPrice = productPrice;
    }
}

package com.somitsolutions.training.java.ExperimentationWithFutureTask;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;
import java.util.concurrent.Callable;

public class Preloader {
    static ExecutorService executor = Executors.newFixedThreadPool(1);
    List<ProductInfo> productInfo = new ArrayList<>();
    private FutureTask<List<ProductInfo>> future = null;

    public List<ProductInfo> get() {
        try {
            productInfo = future.get();
        } catch (InterruptedException | ExecutionException e) {
            e.printStackTrace();
        }
        return productInfo;
    }

    public boolean cancel() {
        return future.cancel(true);
    }

    public boolean isDone() {
        return future.isDone();
    }

    public void start() {
        System.out.println("Tác vụ đang được gửi...");
        future = (FutureTask<List<ProductInfo>>) (executor.submit(new LoadProductInfo()));
    }

    private List<ProductInfo> loadProductInfo() {
        System.out.println(Thread.currentThread().getName());
        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        for (int i = 0; i < 100000; i++) {
            ProductInfo productI = new ProductInfo(Integer.toString(i), i);
            productInfo.add(productI);
        }
        return productInfo;
    }

    class LoadProductInfo implements Callable<List<ProductInfo>> {
        @Override
        public List<ProductInfo> call() throws Exception {
            return loadProductInfo();
        }
    }
}

package com.somitsolutions.training.java.ExperimentationWithFutureTask;

import java.util.List;

public class Main {
    public static void main(String[] args) {
        List<ProductInfo> listOfProductInfo;
        System.out.println(Thread.currentThread().getName());

        Preloader preloader = new Preloader();
        preloader.start();

        int count = 0;
        while (!preloader.isDone()) {
            System.out.println("Tác vụ chưa hoàn thành...");
            count++;
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
                Preloader.executor.shutdown();
                System.exit(0);
            }
            if (count == 100) {
                preloader.cancel();
                System.out.println("Tác vụ đã bị hủy...");
                Preloader.executor.shutdown();
                System.exit(0);
            }
        }

        if (!preloader.cancel() && preloader.isDone()) {
            listOfProductInfo = preloader.get();
        }

        System.out.println(listOfProductInfo.get(0).getProductName());
        System.out.print(listOfProductInfo.get(0).getProductPrice());

        Preloader.executor.shutdown();
    }
}