Amit-sandhu/Learning-Java ? reverse-engineered prompt

Build me a clean Java learning project that teaches the language step by step with small runnable examples.

I want it organized like a course, starting with basics like variables, if else, loops, methods, arrays, and then moving into objects, constructors, static, inheritance, abstract classes, polymorphism, encapsulation, interfaces, generics, enums, wrapper classes, collections, file handling, exceptions, multithreading, lambda streams, and a few DSA practice examples.

Each topic should have a simple explanation in plain language and a matching Java file that demonstrates the idea clearly, so I can read and run it right away. Include a few fun beginner exercises too, like number guessing, rock paper scissors, patterns, matrix add and subtract, and string practice.

Keep the code simple and beginner friendly, and make sure the examples are easy to run one at a time. If you need to, look up current Java docs online for any newer syntax or best practices.