java - Java中通用括号之间没有空格的推理

Question

看着 GenericWhitespaceCheck在 Checkstyle 文档中，

Left angle bracket (<):

• should be preceded with whitespace only in generic methods definitions.
• should not be preceded with whitespace when it is precede method name or following type name.
• should not be followed with whitespace in all cases.

Right angle bracket (>):

• should not be preceded with whitespace in all cases.
• should be followed with whitespace in almost all cases, except diamond operators and when preceding method name.

我不确定我是否完全理解背后的原因 <后面不应该跟一个空格以及为什么 >不应在 1 之前。

换句话说，为什么是 Map<String> session 结束 Map < String > ?

这仅仅是因为随着参数数量和深度的增加，没有空格的版本更具可读性。

喜欢，Map<String, List<String>>比 Map < String, List < String > > 更具可读性?

另外作为一个一般问题，是否有一些存储库/指南可以解释 Checkstyle 约定背后的原因？

Answer 1

简介an early tutorial on generics (从 2004 年开始)说(强调我的):

This tutorial is aimed at introducing you to generics. You may be familiar with similar constructs from other languages, most notably C++ templates. If so, you’ll soon see that there are both similarities and important differences. If you are not familiar with look-a-alike constructs from elsewhere, all the better; you can start afresh, without unlearning any misconceptions.

这是承认 Java 泛型看起来像 C++ 模板。 C++ 模板通常也会省略开头后面的空格 < , 以及收盘前 > .

围绕 Java 泛型的约定将遵循它们在早期教程中的编写方式。