Password checking utilities

Question

Guys,
I read in some of the Java books about a password utilities which checks if passwords are legal(according to the company's policy).
They used something like this:
public static boolean isPasswordValid (String pw)
String digits = "0123456789"
String letters ="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
//something with indexOf()
}and then checked if one of the chars exists in the String pw.
could anyone advise how to check it with indexOf????
I implemented it differently with this:
     public static boolean isPasswordValid(String pw)
          if (pw!=null && pw.length()>5)
               char[] c = pw.toCharArray();
               boolean digitExist  = false;
               boolean letterExist = false;
               for (int x=0; x<pw.length(); x++)
                    if (Character.isDigit(c[x]))
                         digitExist = true;
                    if (Character.isLetter(c[x]))
                         letterExist = true;
                    if (digitExist && letterExist)
                         return true;                    
          return false;
     }

Answer 1

I suggest:
Implementing what you want to do, by using the 'indexOf()' method, is also difficult.
But anyway...
char[] c = digits.toCharArray();
boolean digitExist  = false;
for (int i = 0; i < c.length; i++)
   if (pw.indexOf(c) != -1)
digitExist = true;
break;
//Same for the letters