如何在Java 8中将流的结果收集到自定义对象的数组中

问题描述

我有一个List<TestBuilder> testBuilders;Test具有Test类型的功能构建

I have an List<TestBuilder> testBuilders;Test has a function build of type Test

我做了testBuilders.stream().map(Test::build()).collect()

我想在array of Test i.e Test[]

我不确定collect function

推荐答案

使用终端操作 Stream::toArray ，它将项目序列打包到一个数组中.但是，您必须定义提供的生成器 IntFunction<A[]> 分配返回数组的类型:

Use the terminal operation Stream::toArray which packs the sequence of items into an array. However, you have to define a provided generator IntFunction<A[]> to allocate the type of returned array:

Test[] array = testBuilders.stream().map(Test::build()).toArray(size -> new Test[size]);

lambda表达式size -> new Test[size]应该替换为方法引用:

The lambda expression size -> new Test[size] should be replaced with a method reference:

Test[] array = testBuilders.stream().map(Test::build()).toArray(Test[]::new);

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