What conditions must be met to successfully launch a Java program?

To successfully run a Java program, the following conditions must be met:

1. Install the Java Development Kit (JDK) of the appropriate version.
2. Write a class with a public static void main(String[] args) method, which serves as the entry point.
3. Compile the source code into bytecode using javac.
4. Run the program using the java command, specifying the class name with the main method.

Example:

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, world!");
    }
}

Compilation and execution:

javac HelloWorld.java
java HelloWorld