Any object representing a mutable data source in Java exposes methods for reading and writing its data as a stream. Java.io is the main package for most stream-oriented I/O classes.

Processing streams and insight into classes Java 24 finalizes two important features, with Stream Gatherers and the Class-File API. Both have had two previews each in Java 22 and Java 23.

Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs.

MicroStream abstracts the Java persistence layer so you can think about data persistence in an object-oriented way. Here's a hands-on introduction.