helpdesk structure analysis

package constants: all public classes, fileds in which is public static final, CONSTANT

package core: commonly used classes,  always contains a interface(like class Service, Message and so on)   and classes implement it.

package data: DB Management, including Java Beans for DB. In which, class DataSet defines the data from DB(including fileds col_name, row_data and dataset_name). DBManage manages the DB connection.

package exception: custom exceptions

package jsp: functions seperated from JSP. Inteface Command and interface ContentModel(javabean)。The classed implementing former interface usually have excute function to return object of the latter type.