/**
*  CompletableFuture可以指定异步处理流程：
*   2.1 thenAccept()处理正常结果；
*   2.2 exceptional()处理异常结果；
*   2.3 thenApplyAsync()用于串行化另一个CompletableFuture；
*/
public class CompletableFutureTest {
      
      
   private ABusi busi = new ABusi() ;
    // 基本api使用
    @Test
    public void basicApi() throws InterruptedException {
      
      
        // 创建异步执行任务
        CompletableFuture<Double> cf =
                CompletableFuture.supplyAsync(busi::fetchPrice);
        // 如果执行成功
        cf.thenAccept(result ->{
      
      
            System.out.println("price : " + result);
        }) ;
        // 如果执行异常
        cf.exceptionally(e ->{
      
      
            System.out.println("发生异常：" + e.getMessage());
            return null ;
        }) ;
        // 主线程不要立刻结束，否则CompletableFuture默认使用的线程池会立刻关闭:
        Thread.sleep(200);
    }
}

public class CompletableFutureTest {
      
      
   private ABusi busi = new ABusi() ;
   // 使用thenApplyAsync串行化执行两个异步任务
   @Test
   public void serialExecute() throws InterruptedException {
      
      
       // 第一个任务
       CompletableFuture<String> cfQuery = CompletableFuture.supplyAsync(() -> {
      
      
           return busi.queryCode("中国石油", null);
       });
       // cfQuery成功后继续执行下一个任务
       CompletableFuture<Double> cfFetch = cfQuery.thenApplyAsync(code -> {
      
      
           return busi.fetchPrice(code, null);
       });
       // cfFetch成功后打印结果
       cfFetch.thenAccept(result ->{
      
      
           System.out.println("price : " + result);
       }) ;
       // 主线程不要立刻结束，否则CompletableFuture默认使用的线程池会立刻关闭
       Thread.sleep(2000);
   }
}

public class CompletableFutureTest {
      
      
   private ABusi busi = new ABusi() ;
   @Test
   public void parallelExecute() throws InterruptedException {
      
      
       // 两个CompletableFuture执行异步查询
       CompletableFuture<String> cfQueryFromSina  =
               CompletableFuture.supplyAsync(() -> busi.queryCode("中国石油", "https://finance.sina.com.cn/code/"));
       CompletableFuture<String> cfQueryFrom163  =
               CompletableFuture.supplyAsync(() -> busi.queryCode("中国石油", "https://money.163.com/code/"));
       //使用anyOf合并为一个新的CompletableFuture
       CompletableFuture<Object> cfQuery  =
               CompletableFuture.anyOf(cfQueryFromSina, cfQueryFrom163);
       // 两个CompletableFuture执行异步查询:
       CompletableFuture<Double> cfFetchFromSina  =
               cfQuery .thenApplyAsync(code -> busi.fetchPrice(((String) code), "https://finance.sina.com.cn/price/"));
       CompletableFuture<Double> cfFetchFrom163  =
               cfQuery .thenApplyAsync(code -> busi.fetchPrice((String) code, "https://finance.sina.com.cn/price/"));
       // 用anyOf合并为一个新的CompletableFuture
       CompletableFuture<Object> cfFetch  =
               CompletableFuture.anyOf(cfFetchFromSina, cfFetchFrom163);
       //最终结果
       cfFetch.thenAccept(result ->{
      
      
           System.out.println("price : " + result);
       }) ;
       // 主线程不要立刻结束，否则CompletableFuture默认使用的线程池会立刻关闭:
       Thread.sleep(200);
   }
}

class ABusi{
      
      
    private String queryCode(String name, String url){
      
      
        try {
      
      
            long time = (long)(Math.random() * 100);
            Thread.sleep(time);
        } catch (InterruptedException e) {
      
      
            e.printStackTrace();
        }
        return "601857" ;
    }
    private Double fetchPrice(String code, String url){
      
      
        try {
      
      
            long time = (long)(Math.random() * 100);
            Thread.sleep(time);
        } catch (InterruptedException e) {
      
      
            e.printStackTrace();
        }
        return 5 + Math.random() * 20 ;
    }
    private Double fetchPrice() {
      
      
        try {
      
      
            Thread.sleep(100);
        } catch (InterruptedException e) {
      
      
        }
        if (Math.random() < 0.3) {
      
      
            throw new RuntimeException("fetch price failed!");
        }
        return 5 + Math.random() * 20;
    }
}