在Ant build.properties中添加环境变量

Question

Is it possible to use $XXX_HOME style variables in a build.properties file?

I set path of variable in build.properties like this

ant.home=/opt/java/myanthome

I have a $ANT_HOME environment variable with the correct path. Can I use this environment variable to set my ant.home in b uild.properties ? I tried to add this in build.xml

<property environment="env"/>
<property file="build.properties" />

and in the build.properties file:

ant.home=${env.ANT_HOME}

but this does not work,it says:

${env.ANT_HOME} does not exist

Answer 1

It is possible but there is no sense in doing it.

You can add a filter that pre-processes your property file. Consider the following property file:

ant.home=@ANT_HOME@

Then, you can filter it and load the file into properties, like this:

<filter token="ANT_HOME" value="${env.ANT_HOME}"/>
<copy file="build.properties" tofile="build.properties.filtered" filtering="true" />
<property file="build.properties.filtered" />

The filter task, in addition with filtering=true , will replace the @ANT_HOME@ token by the value of ${env.ANT_HOME} .

But after having done all this, the question is, why filter the property file to begin with? You can just remove the ant.home property from your file and directly use ${env.ANT_HOME} where necessary.