Logics of typical java based web application:-

  • Request data gathering logic
  • Form validation logic
  • Business logic or request processing logic
  • Persistence logic
  • Session management logic
  • Presentation logic
  • Middle ware services

Request data gathering logic:-

    It gathers various details from the client generated request being from web resource program like request parameter values (from data) request header values and other miscellaneous details.

  • The process of verifying format and pattern of the form data by using java code / java script code is called as “form validation logic”.

Example– checking whether email id is having not, @symbols or not

  • The main logic of the applications that process the request & generates the results is called as “business logic”.
  • The logic that interacts with d/b s/w and manipulates data base table data  is called as “persistence logic”(ex- jdbc code, hibernate code)
  • The logic that remembers client data across the multiple requests during a session like sign to sign out is called as “session management logic”.

Use session tracking technique for this.

  • Hidden form fields
  • Cookies
  • Http session with cookies
  • Http session with url rewriting.
  • The logic that generate user interface, formats the results given by business logic is called as “presentation logic” (html code).
  •  The additional services that is configurable on the applications to make app. Is perfect & manipulate in all the situations are called as “middle ware services”

Example: – jdbc connection pooling, transaction management, security etc.

Sample Servlet / JSP Program:-

  • Read value 1, value 2 from the page as req param values.(req. data gathering logic)
  • Check whether they are typed as numeric values or not(form validation logic)
  • Int result = value 1 + value 2;(business logic)
  • Store result in D-B s/w(persistence logic)
  • Apply security service(middle ware service )
  • Store form data in cookies(session management)
  • Display result on browser window as table content. (presentation logic)