如何在Java 7中使用线程池来实现任务的循环执行与返回结果处理

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ThreadPoolExample {
    public static void main(String[] args) {
        // 创建一个固定大小为5的线程池
        ExecutorService executorService = Executors.newFixedThreadPool(5);
        
        // ...
        
        // 关闭线程池
        executorService.shutdown();
    }
}

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class ThreadPoolExample {
    public static void main(String[] args) {
        ExecutorService executorService = Executors.newFixedThreadPool(5);
        
        // 提交任务并获取Future对象
        Future<String> future = executorService.submit(() -> {
            // 任务的具体逻辑
            // 这里以延时1秒返回结果为例
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            return "Hello, World!";
        });
        
        try {
            // 获取任务的返回结果
            String result = future.get();
            System.out.println(result);
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        executorService.shutdown();
    }
}

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class ThreadPoolExample {
    public static void main(String[] args) {
        ExecutorService executorService = Executors.newFixedThreadPool(5);
        
        // 保存每个任务的Future对象
        List<Future<String>> futures = new ArrayList<>();
        
        // 循环执行10个任务
        for (int i = 0; i < 10; i++) {
            final int taskId = i;
            Future<String> future = executorService.submit(() -> {
                // 任务的具体逻辑
                // 这里以延时1秒返回结果为例
                try {
                    Thread.sleep(1000);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return "Task-" + taskId + " is completed.";
            });
            futures.add(future);
        }
        
        // 获取每个任务的返回结果
        for (Future<String> future : futures) {
            try {
                String result = future.get();
                System.out.println(result);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        
        executorService.shutdown();
    }
}