CompletableFuture.allOf 意思

Question

我理解的好吗，我用的时候

CompletableFuture.allOf("array of CompletableFuture")
                 .runAsync(()-> { "piece of code" });

首先我必须等到 CF 数组全部完成，然后 Runnable“代码段”完成？

Answer 1

CompletableFuture.allOf 静态方法允许等待作为 var-arg 提供的所有 Future 的完成。

例如

CompletableFuture<String> future1  
  = CompletableFuture.supplyAsync(() -> "Hello");
CompletableFuture<String> future2  
  = CompletableFuture.supplyAsync(() -> "Beautiful");
CompletableFuture<String> future3  
  = CompletableFuture.supplyAsync(() -> "World");

CompletableFuture<Void> combinedFuture 
  = CompletableFuture.allOf(future1, future2, future3);

Answer 2

也就是文档中显式：

Returns a new CompletableFuture that is completed when all of the given CompletableFutures complet

CompletableFuture.allOf 意思

CompletableFuture.allOf meaning

java

multithreading

completable-future