java bufferedReader question, please help.?

I think this is what you're asking for, but I don't know if System.in will ever return null while your app is running. You might get an empty string; i.e. "" if a user hits return with no data typed in. But, as you describe your problem, here's the code:

BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(System.in));

String nextLine=null;
while((line=bufferedReader.readLine())!=null)
{
// do whatever with non-null lines
}
System.out.println("hello world");

import java.util.Scanner;
Scanner in = new Scanner(System.in);
if (in.nextLine()==null) System.out.print("helloworld");