java.lang.NoClassDefFoundError

Problem Description

When developing Android projects using ExoPlayer in Unity, you might encounter a java.lang.NoClassDefFoundError related to missing dependencies. This issue arises due to the lack of necessary Android dependencies in the Unity project, which causes runtime errors when ExoPlayer components are accessed.

What You Might See

The application crashes with an error message stating:

2024-07-02 11:09:55.169 15114 15114 Error AndroidRuntime java.lang.NoClassDefFoundError: Failed resolution of: Lcom/google/android/exoplayer2/ui/PlayerNotificationManager$NotificationListener;

Root Cause

This crash is primarily due to missing Android dependencies required by ExoPlayer. Unity projects sometimes fail to automatically resolve and include all necessary dependencies, leading to this type of error when trying to use ExoPlayer's features.

Workaround

To fix this issue, you need to force resolve Android dependencies in your Unity project using the External Dependency Manager. This tool ensures that all necessary libraries and dependencies are properly included in your project.

Steps to Resolve

1. Force Resolve Dependencies:

   • Open your Unity project.

   • Navigate to Assets > External Dependency Manager > Android Resolver.

   • Click on Force Resolve.

2. Verify Dependencies:

   • Ensure that all required dependencies are correctly listed and resolved. This may include dependencies for ExoPlayer and other necessary libraries.

3. Rebuild and Test:

   • Rebuild your Unity project.

   • Deploy the project to an Android device or emulator to ensure that the issue is resolved and the application no longer crashes.

By following these steps, you should be able to resolve the NoClassDefFoundError and ensure that all necessary Android dependencies are included in your Unity project, allowing ExoPlayer to function correctly without runtime errors.