You will use these sources .

Question 1

Add a login form to your forum.
  1. The user will type his name and his password
  2. The servlet will check they match those in the forum
  3. If ok, you will store the user object as a Session bean

Question 2

Add a page to create a new message. If the user is not logged, you will send him to the login form.

Question 3

Add a page to edit an existing message. Only administrators and the message owner can edit a message.