在Java中，如何获取线程的结果？

package test;
 
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;
 
public class CallableFutureTest {
 
public static void main(String[] args) {
long startTime = System.currentTimeMillis();
Callable<Integer> calculateCallable = new Callable<Integer>() {
@Override
public Integer call() throws Exception {
// TODO Auto-generated method stub
Thread.sleep(2000);//模拟耗时时间
int result = 1+2;
return result;
}
};
FutureTask<Integer> calculateFutureTask = new FutureTask<>(calculateCallable);
Thread t1 = new Thread(calculateFutureTask);
t1.start();
//现在加入Thread运行的是一个模拟远程调用耗时的服务，并且依赖他的计算结果（比如网络计算器）
try {
//模拟耗时任务，主线程做自己的事情，体现多线程的优势
Thread.sleep(3000);
int a = 3+5;
Integer result = calculateFutureTask.get();
System.out.println("result = "+(a+result));//模拟主线程依赖子线程的运行结果
long endTime = System.currentTimeMillis();
System.out.println("time = "+(endTime-startTime)+"ms");
} catch (InterruptedException | ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}