JDK 1.2.2 Compiler Issue

I installed JDK 1.2.2 last evening and created a simple "Hello World!" application.  The code for this app is ..
class HelloWorldApp {
  public static void main(String[] args) {
    System.out.printIn("Hello World!");
  }
}

When I compile this code, however, I receive the following error:
HelloWorldApp.java:8: Method printIn(java.lang.String) not found in class java.io.PrintStream.
      System.out.printIn("Hello World!");
1 error

I figure this must be a simple configuration issue, i.e., classpath setting, though I am not sure.

Any help would be greatly appreciated.