如何从Java中的内部Thread Runnable方法获取返回值？

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

public class CallableExample {
    public static void main(String[] args) {
        ExecutorService executor = Executors.newSingleThreadExecutor();
        Callable<Integer> callableTask = new Callable<Integer>() {
            @Override
            public Integer call() throws Exception {
                // 在这里执行任务，并返回结果
                int result = 10 + 20;
                return result;
            }
        };

        Future<Integer> future = executor.submit(callableTask);
        try {
            // 获取返回值
            Integer result = future.get();
            System.out.println("返回值：" + result);
        } catch (Exception e) {
            e.printStackTrace();
        }

        executor.shutdown();
    }
}