java内置的future模式

用过Java并发包的朋友或许对Future (interface) 已经比较熟悉了，其实Future 本身是一种被广泛运用的并发设计模式，可在很大程度上简化需要数据流同步的并发应用开发。

jdk的内置实现

import java.util.concurrent.Callable;

public class RealData implements Callable<String> {

    private String para;

    protected RealData(String para){
        this.para = para;
    }

    @Override
    public String call() throws Exception {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < 10; i++) {
            sb.append(para);
            try {
                Thread.sleep(100);
            } catch (Exception e) {
            }
        }
        return sb.toString();
    }

}

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;

public class Main {

    public static void main(String[] args) throws InterruptedException, ExecutionException {
        FutureTask<String> future = new FutureTask<String>(new RealData("a"));
        ExecutorService executor = Executors.newFixedThreadPool(1);
        executor.submit(future);
        executor.shutdown();
        try {
            Thread.sleep(2000);
        } catch (Exception e) {
        }
        System.out.println(future.get());
    }
}