Use of callable

package com.xxl.job.admin.mytest;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.concurrent.*;
import java.util.stream.Collectors;

class Task implements Callable<String> {
    

    private String taskName;
    private ThreadPoolExecutor executorPool;
    public List<Task> depencTasks = new ArrayList<>();
    private int execTime = 0;

    public Task(String taskName, ThreadPoolExecutor executorPool, int execTime) {
    
        this.taskName = taskName;
        this.executorPool = executorPool;
        this.execTime = execTime;
    }

    @Override
    public String call() throws Exception {
    
        List<Future<String>> futures = depencTasks.stream().map(r -> executorPool.submit(r)).collect(Collectors.toList());
        futures.forEach(r-> {
    
            try {
    
                r.get();
            } catch (InterruptedException e) {
    
                throw new RuntimeException(e);
            } catch (ExecutionException e) {
    
                throw new RuntimeException(e);
            }
        });
        TimeUnit.SECONDS.sleep(execTime );
        System.out.println("time=+"+new Date()+",taskName="+taskName+",thread:"+Thread.currentThread());
        return "time"+new Date()+"+,taskName="+taskName;
    }
}

public class ThreadPoll {
    

    public static void main(String[] args) {
    

        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(
                4,
                4,
                0L,
                TimeUnit.SECONDS,
                new LinkedBlockingQueue<>(100),
                Executors.defaultThreadFactory(),
                new ThreadPoolExecutor.CallerRunsPolicy());

        Task task1 = new Task("task1",threadPoolExecutor,0);
        Task task2 = new Task("task2",threadPoolExecutor,1);
        Task task3 = new Task("task3",threadPoolExecutor,1);
        Task task4 = new Task("task4",threadPoolExecutor,1);
        Task task5 = new Task("task5",threadPoolExecutor,10);
        Task task6 = new Task("task6",threadPoolExecutor,10);
        Task task7 = new Task("task7",threadPoolExecutor,1);
        Task task8 = new Task("task8",threadPoolExecutor,1);
        Task task9 = new Task("task9",threadPoolExecutor,1);
        
        task1.depencTasks.add(task2);
        task1.depencTasks.add(task3);
        task1.depencTasks.add(task4);
        task1.depencTasks.add(task5);
        task1.depencTasks.add(task6);
        task2.depencTasks.add(task7);
        task3.depencTasks.add(task8);
        task4.depencTasks.add(task9);

        System.out.println("start time:"+new  Date());
        threadPoolExecutor.submit(task1);
    }
}

Running results ：

start time:Tue Jul 19 16:23:57 CST 2022
time=+Tue Jul 19 16:23:58 CST 2022,taskName=task7,thread:Thread[pool-1-thread-4,5,main]
time=+Tue Jul 19 16:23:59 CST 2022,taskName=task2,thread:Thread[pool-1-thread-2,5,main]
time=+Tue Jul 19 16:24:09 CST 2022,taskName=task5,thread:Thread[pool-1-thread-2,5,main]
time=+Tue Jul 19 16:24:19 CST 2022,taskName=task6,thread:Thread[pool-1-thread-2,5,main]
time=+Tue Jul 19 16:24:20 CST 2022,taskName=task8,thread:Thread[pool-1-thread-2,5,main]
time=+Tue Jul 19 16:24:21 CST 2022,taskName=task3,thread:Thread[pool-1-thread-3,5,main]
time=+Tue Jul 19 16:24:21 CST 2022,taskName=task9,thread:Thread[pool-1-thread-2,5,main]
time=+Tue Jul 19 16:24:22 CST 2022,taskName=task4,thread:Thread[pool-1-thread-4,5,main]
time=+Tue Jul 19 16:24:22 CST 2022,taskName=task1,thread:Thread[pool-1-thread-1,5,main]