spring - Filter integer list in Thymeleaf

Question

I am learning about Thymeleaf in Spring, and I am struggling with list fitlering.

The official Tutorial: Using Thymeleaf does not talk about collection filtering and projection, but I found out that Thymeleaf on Spring uses the Spring Expression Language.

This guide states the following:

• The syntax of the selection (filtering) operator is : ${collection.?[property == value]}
• The syntax of the projection (mapping) operator is : ${collection.![property]}

This is fine if I have a list of objects, for example a list of persons. Then I can perform things like that:

• Selection (filtering): e.g., ${persons.?[age >= 18]} selects all persons of at least 18 years
• Projection (mapping): e.g., ${persons.![name]} selects the name of every person

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Question:

What if I do not have a list of objects (such as a list of persons) but a list of numbers or list of Strings? How can I perform selection (filtering) then? Things like numbers.?[>10] does not work.

标签： springspring-bootthymeleafspring-expressionspring-expression-language

Answer 1

经过一番搜索，我在Spring Expression Language文档中找到了答案。

在10.5.11 变量中，文档说明了#this和#root变量。

变量#this 总是被定义并引用当前的评估对象（针对哪些不合格的引用被解析）。

因此，假设我有一个numbers充满整数的列表，${numbers.?[#this >= 10]}创建一个包含所有至少为 10 的数字的新列表。