在Java中有没有并行调用多个函数的捷径？

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.*;

public class ParallelFunctionCalls {
    public static void main(String[] args) throws InterruptedException, ExecutionException {
        // 创建线程池
        ExecutorService executor = Executors.newFixedThreadPool(5);
        // 创建CompletionService
        CompletionService<Integer> completionService = new ExecutorCompletionService<>(executor);

        // 准备要调用的函数
        List<Callable<Integer>> tasks = new ArrayList<>();
        tasks.add(() -> function1());
        tasks.add(() -> function2());
        tasks.add(() -> function3());

        // 提交任务到线程池，并通过CompletionService获取执行结果
        for (Callable<Integer> task : tasks) {
            completionService.submit(task);
        }

        // 处理执行结果
        for (int i = 0; i < tasks.size(); i++) {
            Future<Integer> result = completionService.take();
            // 可以通过result.get()方法获取每个函数的执行结果
            System.out.println("Function " + (i+1) + " result: " + result.get());
        }

        // 关闭线程池
        executor.shutdown();
    }

    public static int function1() {
        // 实现函数1的逻辑
        return 1;
    }

    public static int function2() {
        // 实现函数2的逻辑
        return 2;
    }

    public static int function3() {
        // 实现函数3的逻辑
        return 3;
    }
}