Velocity学习笔记5——VTL模板中的注释

注释允许在模板中包含描述文字，而这些文字不会被放置到模板引擎的输出中。注释是一种有效的提醒自己和向别人解释你的VTL语句要做什么事情的方法。你也可以把注释用来做其他你认为有用的用途。下面就是一个注释的例子。

## This is a single line comment.

一个单行的注释以##开始，直到行尾才结束。如果你要写很多行的注释，那么不用使用多各单行注释，VTL还提供了多行注释。多行注释以#*开始，以*#结束。下面是一个多行注释的例子。

This is text that is outside the multi-line comment.

Online visitors can see it.

#*

 Thus begins a multi-line comment. Online visitors won't

 see this text because the Velocity Templating Engine will

 ignore it.

*#

Here is text outside the multi-line comment; it is visible.

 

在使用Velocity引擎解析上面的模板时，输出的结果是：

 

This is text that is outside the multi-line comment.

Online visitors can see it.

 

Here is text outside the multi-line comment; it is visible.

 

可以看到，多行注释内的内容是不会输出的。

下面的例子阐明了注释的用法：

This text is visible. ## This text is not.

This text is visible.

This text is visible. #* This text, as part of a multi-line comment,

is not visible. This text is not visible; it is also part of the

multi-line comment. This text still not visible. *# This text is outside

the comment, so it is visible.

## This text is not visible.

用Velocity引擎解析上面的模板，输出的结果是：

 

This text is visible. This text is visible.

This text is visible. This text is outside

the comment, so it is visible.

 

在VTL中还有第三种注释：VTL注释块。VTL注释块用来保存如文档的作者、版本号等信息。例如：

#**

This is a VTL comment block and

may be used to store such information

as the document author and versioning

information:

@author

@version 5

*#