java 8 CompletableFuture (2)

package com.example.demo.future;

import java.util.UUID;
import java.util.concurrent.CompletableFuture;

public class FutureTest {


    /**
     * 获取门店id
     *
     * @return
     */
    private static Long getStoreId() {
        try {

            Thread.sleep(1500); //拟处理远程处理时间
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return Math.round(Math.random() * 10000);
    }

    /**
     * 根据门店Id获取订单数据
     *
     * @return
     */
    private static String getData(String sign) {
        try {

            Thread.sleep(1500); //拟处理远程处理时间
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return String.format("{storeId:%s,orderNo:'%s',sign:%s}",
                Math.round(Math.random() * 10000), UUID.randomUUID().toString(), sign);
    }


    public static void main(String[] args) {

        CompletableFuture<String> orderFuture = CompletableFuture
                .supplyAsync(FutureTest::getStoreId)   //第一步,从远程先获取门店id
                .thenApply(Long::toHexString)    //第二步，将门店id进行签名
                .thenCompose(sign -> CompletableFuture.supplyAsync(() -> getData(sign)));  //第三步，从远程获取订单数据


    }
}