Java 实现Callable接口的方式创建多线程

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


//
public class testTwo {

    public static void main(String[] args) {
        //创建Callable接口实现类的对象
        Window window = new Window();
        //将此Callable接口实现类的对象传递到FutureTask构造器中 创建FutureTask的对象
        FutureTask futureTask = new FutureTask(window);
        //将FutureTask的对象作为参数传递到Tread类的构造器中 创建Tread对象 并start()
         new Thread(futureTask).start();

        try {
            //get返回值即为FutueTask构造器参数Callable实现类重写的call()的返回值
          Object sum=  futureTask.get();
            System.out.println(sum);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }
    }


}
//1.创建一个实现Callable 方法的实现类
class Window implements Callable {
    //实现call方法 将此线程需要执行的操作声明在call中
    @Override
    public Object call() throws Exception {
        int sum = 0;
        for (int i = 1; i <= 100; i++) {
            if (i % 2 == 0) {
                System.out.println(i);
                sum = sum + i;
            }
        }
        return sum;
    }
}