在ArrayList上与对象groovy相交 [英] Intersect on ArrayList with objects groovy

问题描述

我有两个数组列表，它们的对象都是域类'User'

I have two array lists with objects of a domain class 'User'

a = [User : 35, User : 36, User : 37]
b = [User : 32, User : 33, User : 34, User : 35, User : 36, User : 37]

当我执行 intersect ( java.util )时，它将返回一个空列表.如何在数组列表中找到常用对象.

When I perform intersect (java.util), it returns an empty list. How can I find the common objects in array list.

推荐答案

这是因为您将地图(具有相同的键)保留在列表中.

It's because of the fact that You keep maps (with same key) on the list.

尝试:

def a = [User1 : 35, User2 : 36, User3 : 37]
def b = [User4 : 32, User5 : 33, User6 : 34, User1 : 35, User2 : 36, User3 : 37]

assert a.intersect(b) == [User1:35, User2:36, User3:37]

当您将其修改为仅包含ID时，其行为将与预期的一样:

When You modify it to contain IDs only it behaves as expected:

def a = [35, 36, 37]
def b = [32, 33, 34, 35, 36, 37]

assert a.intersect(b) == [35,36,37]

看到了吗?

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