Optimize page: content/english/java/metadata-management/groupdocs-comparison-java-custom-metadata-guide/_index.md - - Updated front matter with current date and SEO‑optimized title/description.

- Integrated primary keyword “set custom metadata java” throughout title, intro, headings, and body (4 occurrences).
- Added Quick Answers, FAQ, and trust‑signal sections for AI search friendliness.
- Expanded explanations, use‑case scenarios, and troubleshooting tips while preserving all original code blocks, links, and shortcodes.
- Reorganized content with question‑based headings for better scannability and GEO compliance.

Author: muqarrab-aspose