如何使用另一个列表中的对象的属性创建新列表 [英] How to make a new list with a property of an object which is in another list

问题描述

想象一下，我有一些特定对象的列表：

Imagine that I have a list of certain objects:

List<Student>

我需要生成另一个列表，包括上面列表中的学生ID：

And I need to generate another list including the ids of Students in the above list:

List<Integer>

避免使用循环，可以通过使用 apache集合或番石榴？哪些方法应该对我的情况有用？

Avoiding using a loop, is it possible to achieve this by using apache collections or guava? Which methods should be useful for my case?

任何帮助都会感激。

推荐答案

Premraj 为替代酷选项，upvote。

Thanks to Premraj for the alternative cool option, upvoted.

我使用了apache CollectionUtils和BeanUtils。因此，我对以下代码的执行感到满意：

I have used apache CollectionUtils and BeanUtils. Accordingly, I am satisfied with performance of the following code:

List<Long> idList = (List<Long>) CollectionUtils.collect(objectList, 
                                    new BeanToPropertyValueTransformer("id"));

值得一提的是，我将比较番石榴的性能（ Premraj 提供）和我上面使用的collectionUtils，并决定更快的。

It is worth mentioning that, I will compare the performance of guava (Premraj provided) and collectionUtils I used above, and decide the faster one.

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