PluginBundleGenerator fails with java 9+

[javierlores]

Problem Description

The PluginBundleGenerator is experiencing a ClassCastException when attempting to generate plugin bundles on Java 9+ due to changes in the classloader architecture.

Specific Error

java.lang.ClassCastException: class jdk.internal.loader.ClassLoaders$AppClassLoader cannot be cast to class java.net.URLClassLoader

Impact

• Breaks plugin bundle generation for Java 9 and newer versions
• Prevents testing and deployment of plugins on modern Java environments
• Requires manual workarounds for development and testing

Root Cause

• Pre-Java 9 code assumes URLClassLoader for classpath scanning
• Java 9+ introduced the Java Platform Module System (JPMS)
• AppClassLoader replaced traditional URLClassLoader

Location

• File: PluginBundleGenerator.java
• Problematic method: generateBundleZip()
• Specific line: Classloader casting and classpath iteration

Priority

• High (Blocks plugin development and testing)

Affected Versions

• Java 9+
• Concourse versions using this bundle generator