Mastering Java, the programming language, involves several key steps:

1. Study the Basics: Start with solid understanding of the basic syntax, data types, control structures, and object-oriented programming concepts.

2. Practice Regularly: Work on small projects and to gain hands-on experience with Java. This will help you become familiar with the language and its features.

3. Learn Data Structures and Algorithms: Understanding fundamental data structures (such as arrays, linked lists, trees, etc.) and common algorithms is crucial for writing efficient Java programs.

4. Explore Java APIs: Java has an extensive standard library with APIs for various tasks such as networking, access, and GUI development. Familiarize yourself with these APIs.

5. Master Object-Oriented Design: Java is an object-oriented language, so understanding concepts like inheritance, polymorphism, and encapsulation is vital.

6. Understandreading and Concurrency: Java is popular for its support ofithreading and concurrency. Mastering these concepts is important for developing robust and efficient applications.

. Build Real-World Projects: Apply your knowledge to create actual applications or systems. This will give you valuable experience and demonstrate skills.

8. Keep Learning: Java is a constantly evolving language with new features and updates. Stay updated with the latest developments and best practices in the Java.

Remember, mastering Java is a continuous process, and staying exposed to practical scenarios and real-world projects will be beneficial in becoming proficient.