Java developer roles span everything from enterprise backend systems to Android development -- your resume should make clear which kind of Java work you actually do.
"Java" alone tells a recruiter little. Mention the frameworks (Spring, Spring Boot, Hibernate), build tools, and architecture patterns you've actually worked with.
If you genuinely know throughput, request volume, or team size for a system you built, include it -- never estimate or invent a number you don't actually know.