Java中使用Callable创建线程的方法

@FunctionalInterface
public interface Callable<V> {
    V call() throws Exception;
}

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;

// 定义Callable实现类
class MyCallable implements Callable<Integer> {
    @Override
    public Integer call() throws Exception {
        int sum = 0;
        for (int i = 1; i <= 100; i++) {
            sum += i;
        }
        return sum;
    }
}

public class CallableThreadExample {
    public static void main(String[] args) {
        // 创建Callable实例
        Callable<Integer> callable = new MyCallable();
        // 创建FutureTask实例，并将Callable实例作为参数传入
        FutureTask<Integer> futureTask = new FutureTask<>(callable);
        // 创建Thread实例，并将FutureTask作为参数传入
        Thread thread = new Thread(futureTask);
        // 启动线程
        thread.start();

        try {
            // 获取Callable任务的执行结果
            Integer result = futureTask.get();
            System.out.println("计算结果: " + result);
        } catch (InterruptedException | ExecutionException e) {
            e.printStackTrace();
        }
    }
}

import java.util.concurrent.*;

class MyCallable2 implements Callable<String> {
    @Override
    public String call() throws Exception {
        Thread.sleep(2000);
        return "任务执行完成";
    }
}

public class CallableThreadPoolExample {
    public static void main(String[] args) {
        // 创建线程池
        ExecutorService executorService = Executors.newFixedThreadPool(3);
        // 创建Callable实例
        Callable<String> callable = new MyCallable2();
        // 提交Callable任务，并返回Future对象
        Future<String> future = executorService.submit(callable);

        try {
            // 获取任务执行结果
            String result = future.get();
            System.out.println(result);
        } catch (InterruptedException | ExecutionException e) {
            e.printStackTrace();
        } finally {
            // 关闭线程池
            executorService.shutdown();
        }
    }
}