CompletableFuture多线程处理任务，等待所有线程处理完并返回结果

疯狂的狮子-Alun

已于 2023-12-22 09:46:11 修改

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文章标签： java 开发语言

于 2023-12-21 21:10:33 首次发布

本文链接：https://blog.youkuaiyun.com/Alun_kong/article/details/135140397

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本文介绍了如何使用JavaCompletableFuture类处理100个异步任务，通过ExecutorService创建线程池，确保所有任务完成后返回结果并计算总耗时。

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CompletableFuture多线程处理任务，等待所有线程处理完并返回结果

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * @Description:
 * @Author: Alun
 * @Date: 2023/12/21 19:43
 * @Version: V1.0
 */
public class CompletableFutureDemo {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        System.out.println("=============开始==============");
        long start = System.currentTimeMillis();
        List<CompletableFuture<String>> allCompletableFuture = new ArrayList<>();
        // 线程池
        ExecutorService executor = Executors.newWorkStealingPool(10);
        for (int i = 0; i < 100; i++) {
            int finalI = i+1;
            // 异步线程
            CompletableFuture<String> completableFuture = CompletableFuture.supplyAsync(() -> {
                String str = task(finalI);
                return str;
            }, executor);
            allCompletableFuture.add(completableFuture);
        }

        // 等待所有线程执行结束
        System.out.println(allCompletableFuture.size());
        for (CompletableFuture<String> stringCompletableFuture : allCompletableFuture) {
            String str = stringCompletableFuture.get();
            System.out.println("=====结果====" + str);
        }
        long time = System.currentTimeMillis() - start;
        System.out.println("=============结束==============");
        System.out.println(String.format("总耗时%s毫秒", time));
    }

    private static String task(Integer taskId) {
        int time = 1000;
        try {
            Thread.sleep(time);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        String str = String.format("任务号: %s, 执行时间: %s 毫秒", taskId, time);
        System.out.println("=====任务====" + str);
        return str;
    }

}