Physical Architecture

The following diagram shows the Physical software architecture of CRM.COM Software.

Clients establish a session to the J2EE web container via an HTTP connection just like normal browsing on the Internet. No plugin or any other software component needs to be installed on the client.

After the session has been established, the client is able to indirectly invoke methods of different business objects (EJB) via the various JSP pages.

The HTTP requests send by the user are mapped to Remote or Local Method calls to the various EJBs. This means that the HTTP URL requested by the user is parsed and translated into method calls. When the user logs in CRM.COM Software four session objects are created:

These session objects hold information about the user; such as security constraints, and the Internal Unit(s) the user belongs to. The Hibernate session object is opened when a transaction is about to take place and closed right after the transaction is committed (or rolled back). In the case of the user log in, the session object will be opened in order for the application to retrieve the user information (if exists) from the database. With the first attempt of a user to log in, after the J2EE server starts up, the Hibernate service begins loading the object mappings in memory (note that the class mappings are loaded only once through out the lifecycle of the application).

In general the user requests (HTTP requests) are mapped to Session EJB method calls, which in turn start up a new Hibernate session to Create, Read, Update or Delete (CRUD) an entity BO according to the method that was actually called. These entity BOs are actually DTO (Data Transfer Objects) that the Hibernate service feeds with data retrieved from the RDBMS; these are in fact the mappings the Hibernate loads on startup. A record in a database table is represented by a corresponding DTO in memory.

CRM.COM Software offers many features and customizations:

• Database independent SQL requests: Using Hibernate makes the CRM.COM Software database independent. The SQL statements used are not RDBMS specific but instead these are HQL (Hibernate Query Language) statements that are translated to the database equivalent (Native) SQL statements by Hibernate itself.

• Function Security: CRM.COM Software denies any access to restricted parts (if any) of the application according to the user’s privileges. Security can be customized through settings

• O/R mapping features: CRM.COM Software takes advantage of most of Hibernate features such as database neutrality, transactions, concurrency, caching etc.