In this section we will extend our quick start sample into to a web based application that comprises of struts and Hibernate support.

Introduction
In this example we will build a simple web based document repository application using hibernate. The document repository under consideration will have categorization of the documents based on the topics (Folder based like structure), Keywords for each document (this will simplify searches), versioning for each document, Document modification history, permissions based access for each entity based on users and groups.

Database scheme.
The concept of properties tables: Here we have extended the concept of Hash tables to the database, Instead of adding more and more columns as per growing needs A properties table is created per Entity, Each property (Prop) table contains name and value pair that stores additional information for particular entity, thus you can store as many properties as you want for a given entity. Getter and setter methods need to be provided from the domain object so that we can represent these properties inside domain objects.

Basic entities.
Basic entities such as User, Group, and Permissions along with Prop tables for each are provided to persistent data for corresponding entities, Now as a business rule a group contains multiple Users and One User can be a part of multiple Groups. Each entity, User, Group, and Permission have UserProp, GroupProp and PremissionProp respectively. The relation between Entity and Prop is one to many. E.g. User can have multiple Properties. (For simplicity, Permission tables are not shown in the model)

Categories and Documents
Category refers to a Folder/Directory like structure on the file system. Each category may or may not have its Parent Category. Category contains information like name, description, creation details, modification deleted and deletion details. Each category can have multiple entries. (Each Folder can contain one or more Documents (Entries) in it. Each Document can have one or more versions in it.(Document corresponds to version). Document contains information such as Title, Body, Summary, life cycle details, version number, keywords, workflow status, Entry details and Attachment details; Document also contains properties associated with it. Attachment is a file associated with each Document, Database stores the name of file stored on the file system and the size of Attachment.