Ascii To URL Assistance Needed

Can someone give me an example of this:

1)The ASCII characters ‘a’ through ‘z’, ‘A’ through ‘Z’, ‘0’ through ‘9’, ‘_’ (underscore), ‘-‘ (dash), ‘.’ (dot), and ‘*’ (asterisk) remain the same.

2) The space (blank) character ‘ ‘ is converted into a plus sign ‘+’.

3) All other characters are converted into the 3-character String “%xy” where xy is the two-digit hexadecimal representation of the lower 8-bits of the character.

I just need some help with this i need some examples of code to do this so i can get working on a project that i need to make read lines of text and turn it into string and input it into a url.

Other than homework, I don't see any reason to reinvent java.net.URLEncoder, right down to copying the spec from the javadoc. So, since this is homework, you're expected to do it yourself.

db

Funny thing is it's not directly related to my homework. It's part of my online lesson I don't understand but thanks for the help.