Need Sample JAVA API for MDM Integration to the Portal for a simple form

I am looking for a document such as How to Guide with sample code in how to integrate MDM with Portal 7.

Here is an example: We have a simple form the require users to input information - the information needs to be saved in MDM - I understand that we need to do that using JAVA API - but I am looking for actual code samples.

Also - for buttons on the form such as Submit and Cancel. What happens when a user click on Submit or Confirm button.

This is most urgent. Thank in you in advance.

Regards,