/actionName!methodName.action by Struts Zero Configuration?

This is not very clear in Struts documentation.

Posts which talks about /actionName!methodName.action syntax:

1. http://depressedprogrammer.wordpress.com/2007/04/04/struts-2-and-zero-configuration-for-actions-and-results/
2. http://blog.newitfarmer.com/j2ee/struts2/558/struts-2-crud-example/

How to perform Struts Validation (JSON Based)?

Good example in http://code.google.com/p/struts2-jquery/wiki/Validation

How to Mybatis <-> Json?

This Chinese article gives an example: http://www.iteye.com/topic/974139