Class Name 

Description 

MultipartRequest 

The MultipartRequest class is used to process the application form. 

Since the application form contains mixed content (both an input stream 

for a file upload, and regular form data), the processing is different from 

a standard doGet() servlet method. Please see Section 5.3 for a 

detailed discussion of file uploading with servlets. 

MyCalendar 

The MyCalendar class is the interface between the MySQL date format 

and the Java date format of the GregorianCalendar class. Conversion 

methods are provided in this class. 

Street 

Supplementary classes to access the corresponding database tables. 

WorkType  

StreetWorkType 

Table 6: Permit System, Description of Internal Classes 

When a servlet is invoked by the servlet engine (i.e. the client has requested the servlet by 

selecting a hyperlink or pressing a button on one of the JSP pages), other methods from non 

servlet classes are called by the servlet to perform the requested action.  This could be storing 

information to, or retrieving information from the database, for example. The servlet also 

displays a result page, e.g. the confirmation that a database update was handled successfully, 

or the contents of a retrieved database result set. A typical servlet doing this is shown below. 

package Permit;

import javax.servlet.*;

import javax.servlet.http.*;

import java.io.*;

import java.sql.*;

// Servlet class to list all companies.

public class CompanyList extends HttpServlet {

// doGet() Handles the HTTP request for listing all companies.

public void doGet(HttpServletRequest req, HttpServletResponse res)

throws ServletException, IOException {

// Instantiate a string buffer to hold the generated HTML page.

StringBuffer str = new StringBuffer();

MyHTML.setApplicationPath(Global.PERMITURL);

// Start page output to the string buffer

// Insert the page header including the style sheet link

MyHTML.startPage(str,"List of All Companies","../style.css");

// Add the page banner

MyHTML.includeHTMLFile(str,"banner_permit.html");

// Add the Navigation Bar

67