java - 将 CompletableFuture 结果传递给另一个

Question

我对 Java 的 CompletableFuture 相对缺乏经验，我可能需要一些帮助。这就是我正在尝试做的事情。

/* I want to use the result of the future in a second one.
 * So basically, what I want to do is to return the second future,
 * but I don't want to block and wait for the first future to complete.
 * /
CompletableFuture<TypeA> -> CompletableFuture<TypeB> 

所以我想知道是否有一种方法可以将第一个 future “链接”到第二个 future ，以便返回一个单一的 future (TypeB)。

Answer 1

thenCompose方法正是这样做的。

这里是 https://www.baeldung.com/java-completablefuture 的示例:

CompletableFuture<String> completableFuture 
  = CompletableFuture.supplyAsync(() -> "Hello")
    .thenCompose(s -> CompletableFuture.supplyAsync(() -> s + " World"));

assertEquals("Hello World", completableFuture.get());

另请查看 difference between thenCompose and thenComposeAsync .