How to create a fully functional application from Java source code?

To create a fully functional Java application from source code, you need to follow several steps:

1. Write the source code in .java files.
2. Compile the source code using the javac compiler, which converts .java files into bytecode .class files.
3. Run the program using the Java Virtual Machine (java), specifying the main class with the main method.

Example commands for compilation and execution:

javac MyApp.java
java MyApp

For more complex projects, build systems like Maven or Gradle are often used to automate compilation, dependency management, and packaging of the application.