Java web development projects the role of each file

JSP all page code
js all javaScript codes
bo generally java class file
dao typically interface processing database method
impl aforementioned implementation of the interface
service is a processing logical database service
action is processing the business logic of the
xml configuration file
jsp give structs request to the configuration file to find the appropriate configuration method, the configuration method to find ways to deal with in the action, and then executed, returns a result, then just look for the configuration file return the results, and then return to the jsp page

which , action in the dealing may occur with database interaction, service in the method is invoked, service in the method will impl in the method through an interface called bo then there is one to one mapping and database files, corresponding to each table in the database