Gradle Build Failure: Upgrade Asciidoctor Convert For Fix?

Encountering build failures in your Gradle project can be a frustrating experience. If you're facing issues with org.asciidoctor.jvm.convert version 3.3.2, specifically an Unable to load class 'org.gradle.util.CollectionUtils' error, this article provides a comprehensive guide to understanding the problem and resolving it by upgrading to a newer version. This guide will walk you through the error, its causes, and how to effectively upgrade your Asciidoctor dependency to get your Spring Boot project back on track. We’ll also explore the benefits of upgrading and potential compatibility considerations.

Understanding the Issue: Unable to Load Class 'org.gradle.util.CollectionUtils'

The error message "Unable to load class 'org.gradle.util.CollectionUtils'" indicates a class compatibility issue between the org.asciidoctor.jvm.convert plugin and your Gradle environment. This typically arises when the plugin version is outdated and relies on classes or methods that are no longer available or have been modified in newer Gradle versions. In simpler terms, the plugin is trying to use a tool that doesn't exist in your current toolbox, or the tool has changed its shape. The org.gradle.util.CollectionUtils class is part of Gradle's internal utilities, and changes to these utilities across Gradle versions can lead to such errors. This issue often surfaces when using older versions of plugins with newer versions of Gradle or Java, as the older plugin might not be aware of the changes and new structures introduced. Identifying the root cause is the first step to solving the problem, and in this case, it points towards an outdated dependency that needs updating.

Root Cause Analysis

To pinpoint the exact cause, consider the following:

• Gradle Version: Are you using a recent version of Gradle? Older plugins might not be compatible with newer Gradle releases.
• Java Version: Similarly, the Java version you are using could be a factor. The example provided uses Java 25, which is a relatively new version, and older plugins might not have been tested or built to be compatible with it. Using a newer Java version can sometimes expose compatibility issues with older libraries.
• Plugin Version: org.asciidoctor.jvm.convert 3.3.2 is an older version. Newer versions often include fixes for compatibility issues and bugs found in previous releases. The age of the plugin is a key factor to consider when troubleshooting this type of error.

By examining these factors, you can confirm that the outdated org.asciidoctor.jvm.convert plugin is the likely culprit. The next step is to explore the benefits of upgrading and how to perform the upgrade.

Reproducing the Error: A Minimal Project Setup

To effectively address this issue, it's helpful to understand how to reproduce the error. The following steps outline a minimal project setup that triggers the Unable to load class 'org.gradle.util.CollectionUtils' error, providing a practical context for troubleshooting and applying the fix.

Steps to Reproduce

1. Initialize a Spring Boot Project: Use start.spring.io to create a new project with the following specifications:
   • Project: Gradle Kotlin
   • Language: Java 25
   • Spring Boot: 4.0.0-RC2 (or RC1)
   • Dependencies: Spring Rest Docs and Spring Web
2. Build the Project: Attempt to build the project using Gradle.
3. Observe the Error: You should encounter the Unable to load class 'org.gradle.util.CollectionUtils' error during the build process. This error confirms the incompatibility between the older Asciidoctor plugin version and the project's environment.

This setup provides a controlled environment to test the fix, which involves upgrading the org.asciidoctor.jvm.convert dependency. Understanding the reproduction steps is crucial for verifying that the upgrade resolves the issue.

The Solution: Upgrading org.asciidoctor.jvm.convert

The most straightforward solution to the "Unable to load class 'org.gradle.util.CollectionUtils'" error is to upgrade the org.asciidoctor.jvm.convert dependency to a more recent version. The latest version, as of the original report, is 4.0.5. Upgrading ensures you're using a version that is compatible with newer Gradle and Java versions, and it often includes bug fixes and performance improvements.

Benefits of Upgrading

• Compatibility: Newer versions are designed to work seamlessly with the latest Gradle and Java releases.
• Bug Fixes: Upgrades typically include fixes for known issues, including class loading problems.
• Performance Improvements: Newer versions often come with optimizations that enhance build performance.
• New Features: Upgrading may provide access to new features and functionalities offered by the latest version of the plugin.

How to Upgrade

To upgrade the org.asciidoctor.jvm.convert dependency, you need to modify your project's build.gradle.kts file. Follow these steps:

1. Locate the Dependency: Open your build.gradle.kts file and find the section where dependencies are declared. This section usually starts with dependencies {.

2. Update the Version: Locate the line that declares the org.asciidoctor.jvm.convert dependency and change the version number to 4.0.5 (or the latest stable version).

   dependencies {
       // ... other dependencies
       implementation("org.asciidoctor.jvm.convert:org.asciidoctor.jvm.convert:4.0.5")
       // ...
   }
   

3. Sync Gradle: After making the changes, sync your Gradle project to apply the new dependency version. In IntelliJ IDEA or Android Studio, you can do this by clicking the "Sync Now" button that appears in the Gradle tool window.

4. Clean and Rebuild: Clean and rebuild your project to ensure that the changes are applied correctly. This step is crucial for removing any cached versions of the older dependency and forcing Gradle to use the new version.

   ./gradlew clean build
   

By following these steps, you can effectively upgrade the org.asciidoctor.jvm.convert dependency and resolve the Unable to load class 'org.gradle.util.CollectionUtils' error. The next section will discuss potential compatibility considerations when upgrading.

Compatibility Considerations

While upgrading org.asciidoctor.jvm.convert is the recommended solution, it's essential to consider potential compatibility issues that may arise. Upgrading a dependency can sometimes introduce breaking changes or conflicts with other libraries in your project. Therefore, it's crucial to approach the upgrade thoughtfully and be prepared to address any compatibility-related issues.

Potential Issues

• Breaking Changes: Newer versions of the plugin may introduce breaking changes that require adjustments to your code. These changes could involve API modifications, deprecated methods, or altered behavior.
• Dependency Conflicts: The upgraded plugin might have dependencies that conflict with other libraries in your project. This can lead to runtime errors or unexpected behavior.
• Gradle Version Compatibility: Ensure that the new version of org.asciidoctor.jvm.convert is compatible with your Gradle version. Refer to the plugin's documentation for compatibility information.
• Java Version Compatibility: Similarly, verify that the upgraded plugin supports the Java version you are using.

Mitigation Strategies

1. Review Release Notes: Before upgrading, carefully review the release notes and migration guides for the new version. These documents often provide details on breaking changes and how to address them.
2. Test Thoroughly: After upgrading, run comprehensive tests to ensure that your application functions as expected. Pay close attention to areas that use Asciidoctor functionality.
3. Check Dependencies: Use Gradle's dependency management features to identify and resolve any dependency conflicts. Tools like the dependencies task can help you analyze your project's dependency tree.
4. Gradual Upgrade: If possible, consider a gradual upgrade approach. Upgrade one minor version at a time, testing after each upgrade to identify issues early.
5. Rollback Plan: Have a rollback plan in place in case the upgrade introduces critical issues. This might involve reverting to the previous version or applying temporary fixes.

By being mindful of these compatibility considerations and implementing appropriate mitigation strategies, you can ensure a smooth upgrade process and minimize the risk of introducing new issues.

Conclusion

In conclusion, encountering the "Unable to load class 'org.gradle.util.CollectionUtils'" error while building a Gradle project with org.asciidoctor.jvm.convert 3.3.2 typically indicates a compatibility issue. The most effective solution is to upgrade to a newer version, such as 4.0.5 or later, to ensure compatibility with modern Gradle and Java environments. By following the steps outlined in this guide, you can upgrade your Asciidoctor dependency, resolve the error, and benefit from the latest features and bug fixes.

Remember to consider potential compatibility issues and test thoroughly after upgrading. A well-planned upgrade process can prevent unexpected problems and keep your Spring Boot project running smoothly. Always refer to the official documentation and release notes for the most accurate and up-to-date information. For more information on Gradle and dependency management, visit the Gradle official documentation. This resource provides in-depth information on managing dependencies in Gradle projects and can help you further optimize your build process.