Glossary: Java Basics

Topics for the next book

Also written: Interface, interfaces, lambdas, streams, Optional, Maven, Gradle, JUnit, virtual threads, concurrency

Further Java topics beyond the basics: interfaces, lambdas and streams, `Optional` (a safer alternative to `null`), Maven and Gradle (project builders), JUnit (testing) and virtual threads (concurrency). They are the natural next steps after learning the core of the language.