The famous "Java Programming I & II" from the University of Helsinki is an online text-based course. Some third-party archivists have compiled the material into a single PDF. While the official site recommends the interactive version, the PDF can be found via university GitHub repositories.
Encapsulation: Using private fields and public getters/setters to protect data. Inheritance: Creating class hierarchies using 'extends'. java in 2 semesters pdf
They demonstrate how to structure a large Java application, which is crucial for passing a second-semester course. Software Engineer Self-Taught Developer Java Tutorial - W3Schools The famous "Java Programming I & II" from