techno.blog("Dion")

javap is one of those nice command line tools that you can use to print out info on a given class.

I sometimes run into problems in a project where the right jars may not all be in my lib directories (see last post ;).

I use a simple ant task to give me a sanity check (outside of my IDE of course, as that may be setup differently).

I run:

% ant find-class -Dclass.name=java.lang.String

and the simple task is…

<!-- =================================================================== -->
<!-- Find the class in the classpath                                     -->
<!-- =================================================================== -->
<target name="find-class" description="Find the class in the classpath">
<fail unless="class.name"
message="You must pass a class name in via -Dclass.name=package.class"/>

<echo message="Finding class: ${class.name}"/>

<exec executable="javap">
<arg line="-classpath ${project.classpath} ${class.name}"/>
</exec>
</target>

I am always surprised that I can’t find a <javap> ant task too.