[newsoftheday]

You can do this in Java 21, create this small Java file and run it immediately:

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

Include the .java extension, you're running the file directly.

time java HelloWorld.java

    Hello, World!

    real    0m0.278s
    user    0m0.613s
    sys     0m0.066s

[oftenwrong]

You can do better now:

    #!/usr/bin/env java --source 25
    void main() {
        IO.println("Hello, World!");
    }

https://openjdk.org/jeps/330 https://openjdk.org/jeps/458 https://openjdk.org/jeps/512

I often combine these approaches with https://get-coursier.io/ when I need to fetch third-party dependencies.