Ant：如何在包含refid时回显路径？

Question

Please see this ant snippet below --

<path id="classpath.ejb">
    <path refid="${java.class.path}"/>
    <pathelement location="${my.id}_session_${version.suffix}.jar"/>
</path>

Here I want to see the content of classpath.ejb , the fact is that it is composed of two elements, one is the generic system $CLASSPATH (supplied as a refid ) and the second one is some another jar. Just for my curiosity, I want to make sure the contents of classpath.ejb looks fine. But when I try to echo like --

<echo message="java.class.path: ${java.class.path}"/>
<echo message="classpath.ejb: ${toString:classpath.ejb}"/>

The first echo works, but in the second line, ant says that --

BUILD FAILD
build.xml:103:Reference <...my whole $CLASSPATH string...> not found. 

Any idea ??

Answer 1

Your <path> is faulty. In this line:

<path refid="${java.class.path}"/>

You are saying the value of ${java.class.path} is a reference, but it's not, it is a 'string' path. Hence your error about a missing reference. You could change it to, for example,

<path path="${java.class.path}"/>

So that the classpath.ejb path is composed from the Java classpath and your 'session' jar. Or else, see Path-like Structures in the Ant docs.