You will have to code extra rules to check that your password is acceptable for the system you are writing it for. Some systems have policies like "two digits and two uppercase letters minimum" and so on. As you generate your password character by character, keep a count of the digits/alpha/uppercase as required, and wrap the password generation in a do..while that will repeat the password generation until (digitCount>1 && alphaCount>4 && upperCount>1), or whatever.
