Reading a user-defined String with restrictions

Question

Hey,
I'm fairly new to Java and i'm having to cram a truckload worth of it into my tiny tiny brain in first semester for my course.
I want to read and store a user name chosen by the user, however, I want to implement restrictions on what characters must be included:
an example is that it must start with a letter, contain at least one digit, contain at least one symbol or punctuation mark, between 4 and 8 characters
and must not contain spaces.
I used a +(Character.isLetter(userName.charAt(0))==false)+ line to check whether the first character is a letter and
(userName.indexOf(" ") for the spaces. However no matter how hard I try i cannot seem to figure out how to implement the other restrictions.
Any feedback on this would be much appreciated.
cheers

Answer 1

String userName;
          Scanner sc1;     
          Scanner sc2;     
          int turnNum, round;
          double playerScore;
          boolean validName;
          int length;
          sc1=new Scanner(System.in);
          sc2=new Scanner(System.in);
          userName=new String();
          length=userName.length();
          System.out.println("The Text-Adventure Begins!");
          System.out.println("Please enter your desired User Name: ");
          userName=sc1.nextLine();
          if (!Character.isLetter(userName.charAt(0)))
               validName=false;
               System.out.println("Your User Name is Invalid. It must start with a letter!");
          if (userName.indexOf(" ")!=-1)     
               validName=false;
               System.out.println("Your User Name is Invalid. It must not contain spaces!");
          if ((length <= 3)||(length >= 9))
               validName=false;
               System.out.println("Your User Name is Invalid. It must be between 4 and 8 characters long!");
Some of the variables haven't actually been used yet, but aside from that, the restriction on whether it starts with a letter, and whether it contains a space seem to function. However, I'm not entirely sure how to enforce at least one compulsory digit or punctuation symbol and the character length bit of code won't work no matter how much i fiddle around. Am in the right direction using these methods (remembering that I am only doing a first semester java unit so probably no regex as previously mentioned)? I'm completely at a loss!