[英]Difference between thenAccept and thenApply
I'm reading the document on CompletableFuture
and The description for thenAccept()
is我正在阅读
CompletableFuture
上的文档, thenAccept()
的描述是
Returns a new CompletionStage that, when this stage completes normally, is executed with this stage's result as the argument to the supplied action.
返回一个新的 CompletionStage,当此阶段正常完成时,将使用此阶段的结果作为所提供操作的参数来执行。
and for thenApply()
is对于
thenApply()
是
Returns a new CompletionStage that, when this stage completes normally, is executed with this stage's result as the argument to the supplied function.```
返回一个新的 CompletionStage,当这个阶段正常完成时,将这个阶段的结果作为提供函数的参数执行。```
Can anyone explain the difference between the two with some simple examples?谁能用一些简单的例子来解释两者之间的区别?
You need to look at the full method signatures:您需要查看完整的方法签名:
CompletableFuture<Void> thenAccept(Consumer<? super T> action)
<U> CompletableFuture<U> thenApply(Function<? super T,? extends U> fn)
thenAccept
takes a Consumer
and returns a T=Void
CF, ie one that does not carry a value, only the completion state. thenAccept
接受一个Consumer
并返回一个T=Void
CF,即一个不携带值,只有完成状态的值。
thenApply
on the other hand takes a Function
and returns a CF carrying the return value of the function.另一方面,
thenApply
接受一个Function
并返回一个携带函数返回值的 CF。
thenApply
returns result of curent stage whereas thenAccept
does not. thenApply
返回当前阶段的结果,而thenAccept
不返回。
Read this article: http://codeflex.co/java-multithreading-completablefuture-explained/阅读这篇文章: http : //codeflex.co/java-multithreading-completablefuture-explained/
As the8472 clearly explained, they are differentiate by their output value and args and thus what you can do with them正如the8472清楚地解释的那样,它们通过输出值和参数来区分,因此你可以用它们做什么
CompletableFuture.completedFuture("FUTURE")
.thenApply(f -> f.toLowerCase())
.thenAccept(f -> System.out.println(f))
.thenAccept(f -> System.out.println(f))
.thenApply(f -> new String("FUTURE"))
.thenAccept(f -> System.out.println(f));
future
null
FUTURE
the Apply functions apply another function and pass a future holding a value Apply函数应用另一个函数并传递一个持有值的未来
the Accept functions consume this value and returns future holding void Accept函数消耗这个值并返回未来的持有无效
I would answer this question in the way I remember the difference between the two: Consider the following future.我会以我记得两者之间的区别的方式来回答这个问题:考虑以下未来。
CompletableFuture<String> completableFuture
= CompletableFuture.supplyAsync(() -> "Hello");
ThenAccept
basically takes a consumer and passes it the result of the computation CompletableFuture<Void>
ThenAccept
基本上接受一个消费者并将计算的结果传递给它CompletableFuture<Void>
CompletableFuture<Void> future = completableFuture
.thenAccept(s -> System.out.println("Computation returned: " + s));
You can associate this with forEach
in streams
for easy remembering.您可以将其与
streams
forEach
相关联以便于记忆。
Where as thenApply
accepts a Function
instance, uses it to process the result and returns a Future that holds a value returned by a function:当
thenApply
接受一个Function
实例时,使用它来处理结果并返回一个包含函数返回值的 Future :
CompletableFuture<String> future = completableFuture
.thenApply(s -> s + " World");
You can associate this with map
in the streams
as it is actually performing a transformation.您可以将其与
streams
map
相关联,因为它实际上正在执行转换。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.