What Java libraries or frameworks have you used in your projects?

The following libraries and frameworks are commonly used in Java projects:

• Spring Framework (including Spring Boot) — for creating web applications and dependency management.
• Hibernate — ORM for working with databases.
• JUnit — for writing unit tests.
• Log4j / SLF4J — for logging.
• Apache Commons — a set of utilities for various tasks.
• Jackson / Gson — for serialization and deserialization of JSON.
• Maven / Gradle — build systems and dependency management.

The choice depends on the specifics of the project, but these libraries are fundamental and widely used.