Java Programming Language is, no doubt, one of the leading programming languages today, powering many android apps development, development of general desktop apps and web applications.

Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose language intended to allow application developers to "write once, run anywhere" (WORA), meaning that compiled Java code can run on all platforms that support Java without the need to recompile.

Even though it is generally considered expensive,. learning Java Programming Language, there are  some top resources to learn Java programming for free.

The free sources for learning Java Programming Language are:

Online Courses

Java Tutorial for Complete Beginners by Udemy: A popular course covering Java basics, suitable for beginners and intermediate learners. It is free and available for public access on Udemy.

Object-Oriented Programming in Java by Coursera: An intermediate-level course focusing on OOP concepts including Have codes snippets, code blocks and examples.

Java Programming Basics by Coursera: A beginner-friendly course introducing Java fundamentals by Coursera. It is free and publicly accessible by anyone on Coursera.

Learn Java from Scratch by Educative: This is an interactive, text-based course for beginners on the Educative tutorial platform.

YouTube Channels

You can also learn Java programming language for free on various YouTube channel. Some of the channel are:

freeCodeCamp: Offers comprehensive Java tutorials and projects. It is free, with collection of courses available for your perusal at any time of the day.

Programming with Mosh: Mush is a Java programmer providing high quality beginner-friendly Java tutorials and explanations on his YouTube channel.

Interactive Platforms

Java Programming Language can as well be learned on various interactive platforms where questions related to what you do not understand could be asked while responses are submitted by fellows on the platform. Examples of interactive platforms providing those services are:

Codecademy: Codecademy offers l interactive Java courses and exercises. You are free to access the available resources on the platform and begin to acquire the skill of Java Programming.

JetBrains Academy:  This platform provides interactive Java coding challenges and projects.

CodeGym: A platform for practicing Java programming with exercises and projects.

Java documentation and tutorials: Oracle's official Java documentation and tutorials. This is a material provided by the developer of Java Programming Language, Oracle. This  course is available for free and covers a lot of code phases in Java Programming.

Java forums and communities: You can also join online forums and communities for Java, like Reddit's r/learnjava, to connect with other Java learners and developers, and grow with your colleagues.

Free eBooks:  You can download free Java programming eBooks, such as "Java: A Beginner's Guide"  from Google sources and start studying the Java Programming Language for free.