Java Tester File return null

I would like to use a test file to read several objects, but I got a null from step2 to step 4.

For name, if i input Steven, I would like to get ste123 back (123 should be a random number)

Here is the code:

public class Lab14Tester
{

    public static void main(String[] args)
    {
        Introduction step1 = new Introduction();
        System.out.println(step1.giveline1());
        System.out.println(step1.giveline2());
        System.out.println(step1.giveline3());
        System.out.println(step1.giveline2());
        System.out.println(step1.giveline1());

        Scanner in= new Scanner(System.in);
        System.out.print("\nName: "); 
        String inputname = in.nextLine();
        Username step2 = new Username();
        String givename = step2.givename();
        System.out.println("Your username is " + givename);

        System.out.print("\nGive me a number: ");
        int inputnumber =in.nextInt();
        OddEven step3 = new OddEven();
        System.out.println(step3.givenumbertype());

        System.out.print("\nGive me a number grade: ");
        double grade = in.nextDouble();
        NumberToLetter step4 = new NumberToLetter();
        System.out.printf("\n%.1f", grade);
        System.out.print(" is equal to a " + step4.giveletter());
    }
}


public class Username
{

    private String subname;
    private int randomnumber;
    private String outputname;

    public void getname(String inputname)
    {
        subname = inputname.substring(0,3);
        randomnumber = (int)(Math.random()*1000);
        outputname = subname + randomnumber;
    }

    public String givename()
    {
        return outputname;
    }
}