Optimize page: content/english/java/advanced-comparison/master-document-comparison-java-groupdocs-api/_index.md - - Updated title, description, and front‑matter date to include primary keyword.

- Added Quick Answers, FAQ, and trust‑signal sections for AI and SEO.
- Integrated primary keyword “java compare pdf files” 4 times and secondary keywords naturally.
- Expanded introductions, use‑case explanations, and best‑practice guidance.
- Preserved all original markdown links, code blocks, and formatting unchanged.

Author: muqarrab-aspose