Free and Open Source, Distributed, RESTful Search Engine

Redisson - Easy Redis Java client and Real-Time Data Platform. Valkey compatible. Sync/Async/RxJava/Reactive API. Over 50 Redis or Valkey based Java objects and services: Set, Multimap, SortedSet, …

MyBatis SQL mapper framework for Java

Roadmap to becoming a Java developer in 2024

Spring Boot starter module for gRPC framework.

The Hypersistence Utils library (previously known as Hibernate Types) gives you Spring and Hibernate utilities that can help you get the most out of your data access layer.

🔥 HAPI FHIR - Java API for HL7 FHIR Clients and Servers

Go further into "Learn Spring Security":

Example Spring codebase containing real world examples (CRUD, auth, advanced patterns, etc) that adheres to the RealWorld API spec.

Rich Criteria API for JPA providers

Spring Data JPA extension allowing full dynamic usage of EntityGraph on repositories

Sample GraphQL server implemented with graphql-java and Spring Boot

Spring Boot integration with Netty