为什么Stream没有toList（）方法？ [英] Why didn't Stream have a toList() method?

问题描述

使用Java 8流时，采用列表，从中创建流，执行业务并将其转换回来是很常见的。类似于：

When using the Java 8 streams, it's quite common to take a list, create a stream from it, do the business and convert it back. Something like:

 Stream.of(-2,1,2,-5)
        .filter(n -> n > 0)
        .map(n -> n * n)
        .collect(Collectors.toList());

为什么' .collect没有捷径/方便的方法（Collectors.toList（））'part？在Stream接口上，有将结果转换为数组的方法，名为 toArray（），为什么 toList（）是缺少？

Why there is no short-cut/convenient method for the '.collect(Collectors.toList())' part? On Stream interface, there is method for converting the results to array called toArray(), why the toList() is missing?

恕我直言，将结果转换为列表比数组更常见。我可以忍受这种说法，但称这种丑陋是令人讨厌的。

IMHO, converting the result to list is more common than to array. I can live with that, but it is quite annoying to call this ugliness.

任何想法？

推荐答案

最近我写了一个名为 StreamEx 的小型库，它扩展了Java流并在许多方面提供了这种方法。其他功能：

Recently I wrote a small library called StreamEx which extends Java streams and provides this exact method among many other features:

StreamEx.of(-2,1,2,-5)
    .filter(n -> n > 0)
    .map(n -> n * n)
    .toList();

还有toSet（），toCollection（Supplier），join（），groupingBy（）和其他快捷方法那里有。

Also toSet(), toCollection(Supplier), joining(), groupingBy() and other shortcut methods are available there.

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