I copied a simple java app from a book, but am getting a missing class error.

This is the app:

```
# cat MyFirstApp.java
public class MyFirstApp {
   public static void main (String[] args) {
       System.out.println("I Rule!");
       System.out.println("The World");
      }
}

```

It compiles:

```
[root@dev hfjava]# javac MyFirstApp.java
[root@dev hfjava]#

```

But when I go to run the program I get this error:

```
[root@dev hfjava]# java MyFirstApp.java
Error: Could not find or load main class MyFirstApp.java

```

What am I doing wrong?