Java 和 ProGuard - taskdef class proguard.ant.ProGuardTask 无法使用类加载器 AntClassLoader 找到

Question

I have the pleasure of working on a embeded java program, which was writen 10+ years ago from a third party company. Source and project files were included.

It was imported into Eclipse and ported to a higher java version (17).

Now I'm stuck when trying to build the program. It uses ProGuard. The newest version was added to the project files. Config file proguard.pro was changed to discard rt.jar utilization in favore of the new methods. However, now I'm getting a error message:

BUILD FAILED
C:\mypath\build.xml:16: taskdef class proguard.ant.ProGuardTask cannot be found
 using the classloader AntClassLoader[C:\mypath\obf\proguard.jar]

build.xml (original) is as follows:

<target name="obfuscate" description="obfuscate a jar file" depends="jar">
    <taskdef name="proguard" classname="proguard.ant.ProGuardTask" classpath="obf/proguard.jar" />
    <proguard configuration="obf/proguard.pro" />
</target>

The 'obf' folder is inside the project (sublevel of build.xml). File proguard.jar is inside of it. Anyone haveing any clues why would this error show? No other changes were made beside the listed ones.

Answer 1

So, it turned out that with new versions, the notation is not as it once was.

<taskdef resource="proguard/ant/task.properties" classpath="${proguard.path}/lib/proguard-ant.jar" />