本文介绍了如何使用Streams api peek()函数并使其工作?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

根据, peek()很懒,这意味着我们应该以某种方式激活它。事实上,要激活它以向控制台输出内容我尝试了这个:

According to this question, peek() is lazy it means we should somehow activate it. In fact, to activate it to print something out to the console I tried this :

Stream<String> ss = Stream.of("Hi","Hello","Halo","Hacker News");
ss.parallel().peek(System.out::println);
System.out.println("lol"); // I wrote this line to print sth out to terminal to wake peek method up

但是没有工作和输出是:

But that doesn't work and the output is :

lol

因此,如何让 peek 函数真正起作用?

Thus, how can I make the peek function actually work?

如果没有办法,那么使用 peek 是什么意思?

If there is no way to that so whats the point of using peek?

推荐答案

你必须使用在流上执行(peek不是终端,它是一个中间操作,返回一个新流),例如count():

You have to use terminal operation on a stream for it to execute (peek is not terminal, it is an intermediate operation, that returns a new Stream), e.g. count():

Stream<String> ss = Stream.of("Hi","Hello","Halo","Hacker News");
ss.parallel().peek(System.out::println).count();

或用<$ c $替换 peek c> forEach (这是终端):

Or replace peek with forEach (which is terminal):

    ss.parallel().forEach(System.out::println);

这篇关于如何使用Streams api peek()函数并使其工作?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

09-18 06:47