Future模型

Future模式

创建1~n个线程执行别的异步任务，并可要求这些线程返回异步任务的执行结果。

code

package concurrent;
import java.util.concurrent.*;
public class C12_FuturePattern {
    static class RealData implements Callable<String>{
        private String data;
        public RealData(String data){ this.data = data; }
        @Override
        public String call() throws Exception {
            Thread.sleep(2000); //模拟任务
            return data.toUpperCase();
        }
    }
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        //1.创建线程池
        ExecutorService es = Executors.newFixedThreadPool(1);
        //2.提交一个实现了Callable接口的任务并立即返回
        Future<String> future = es.submit(new RealData("abcdefg"));
        System.out.println("task was submit.");
        //3.主线程做其他事情
        doOtherWork();
        //4.主线程通过future获取所提交任务返回的数据，若还没完成那么会在get函数出阻塞
        System.out.println(future.get());
        es.shutdown();
    }
    public static void doOtherWork(){
        System.out.println("other work was completed, wait for future.get().");
    }
}

console

task was submit.
other work was completed, wait for future.get().
ABCDEFG