ant - 是否可以将属性的值指定为 ant 中的属性？

Question

我有一个属性文件，它是在执行过程中由我的 ant 脚本本身生成的。我想从这个生成的属性文件中访问属性的值。

例如，

生成的属性文件:

first.prop=abcd
second.prop=pqrs

在脚本中，我试图像这样访问它，

我有一个来自其他一些属性的属性名称(我想访问它并且在生成的属性文件中)。该属性是 name.prop .
所以，

<echo message="${name.prop}"/>
<echo message="${${name.prop}}"/>

给

first.prop
${${name.prop}}

分别作为输出。
有什么办法可以解决这个问题？

Answer 1

这是来自 doc :

Nesting of Braces

In its default configuration Ant will not try to balance braces in property expansions, it will only consume the text up to the first closing brace when creating a property name. I.e. when expanding something like ${a${b}} it will be translated into two parts:

• the expansion of property a${b - likely nothing useful.
• the literal text } resulting from the second closing brace

This means you can't use easily expand properties whose names are given by properties, but there are some workarounds for older versions of Ant. With Ant 1.8.0 and the the props Antlib you can configure Ant to use the NestedPropertyExpander defined there if you need such a feature.

所以不容易获得。解决方法(使用 <script /> 或 <macrodef /> 可以找到 here in the official ant faq 。