java thenAccept 和 thenApply 的区别
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Difference between thenAccept and thenApply
提问by Anqi Lu
I'm reading the document on CompletableFutureand The description for thenAccept()is
我正在阅读文档CompletableFuture，其描述thenAccept()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提供的操作的参数来执行。
and for thenApply()is
因为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？
回答by the8472
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)
thenAccepttakes a Consumerand returns a T=VoidCF, i.e. one that does not carry a value, only the completion state.
thenAccept接受 aConsumer并返回一个T=VoidCF，即不携带值，只有完成状态的CF。
thenApplyon the other hand takes a Functionand returns a CF carrying the return value of the function.
thenApply另一方面，接受 aFunction并返回一个携带函数返回值的 CF。
回答by ybonda
thenApplyreturns result of curent stage whereas thenAcceptdoes not.
thenApply返回当前阶段的结果，而thenAccept不会。
Read this article: http://codeflex.co/java-multithreading-completablefuture-explained/
阅读这篇文章：http: //codeflex.co/java-multithreading-completablefuture-explained/
回答by shahaf
As the8472clearly explained, they are differentiate by their output value and args and thus what you can do with them
正如8472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 Applyfunctions apply another function and pass a future holding a value
在应用功能应用其他功能，并通过未来持有价值
the Acceptfunctions consume this value and returns future holding void
在接受功能消耗这个价值和回报的未来持无效
