if you want to know more on OAuth2 and when to use it as authentication and authorization protocol then you can search about it on google and i'll put some URLs later.
Now I assume you are familiar with java web applications using Spring and maven.
to get started we need to create the server side with all dependencies required and i'll list them here, i'll use maven 2 to ease downloading dependencies for us.
1- Create new maven project with arch type webapp:
2- Add the required depenedencies for spring, spring security, spring-oauth2, hibernate & other libraries (required for this tutorial only you can use other libraries if you like)
3- I used hibernate to automate the creation of the schema required by spring OAuth2 to manage tokens (it's required to have schema created in db if you are using jdbc token store).
I use wamp server and phpmyadmin to create my database
4- Setup hibernate mapping [I used xml file, but I think annotations will work too]
5- Create login service interface and stub implementation
6- Create custom authentication provider
7-Create the properties file required for db conneciton
8-Create spring-security.xml (we will go over the contents in the next part)
9-Create security-beans.xml to gather spring configurations related to security in one place
10-Create spring-beans.xml to gather all configurations in one file
11-Configure web.xml, and add mvc-dispatcher-servlet.xml
after all this if I didn't forget anything you will have the following (click on the image to see it in original size):