niit源码--Developing java applications using servlet and jsp1

 1 //GenericServlet
 2 public class SettingCntx extends GenericServlet
 3 {    
 4     ServletContext ctx;    //ServletContext 
 5     public void init(ServletConfig cfig){
 6     /*Obtain the ServletContext object*/    
 7 
 8     }
 9     public void service(ServletRequest request, ServletResponse repose)
10         throws ServletException, IOexception {
11         /*Set the context attribute*/
12         ctx.setAttribute("URL","jdbc:odbc:EmployeesDB");
13         /*Obtain the PrintWriter object*/
14         PrintWrter pw=respone.getWriter();
15         respone.setContentType("text/html");
16         pw.println("<B>The JDBC URL has been set as a context attribute </b>");
17     }
18 }

The RetrievingCntx servlet retrieves the url attribute and displays the value of the attribute.You can use the following code to create the servlet,RetrievingCntx to retrieve and display the url:

 1 import javax.servlet.*;
 2 import java.io.*;
 3 
 4 public class RetrievingCntx extends GenericServlet
 5 {
 6     ServletContext ctx;
 7     String  url;
 8 
 9     public void init(ServletConfig cifg){
10         /*Obtain the ServletContext object*/
11         ctx =cfig.getServletContext();
12     }
13     public void service (ServletRequest request,ServletResponse response)
14         throws ServletException,IOException {
15             url=(String)ctx.getAttribute("URL");
16             PrinterWriter pw=response.getWriter();
17             response.setContentType("text/html");
18             pw.println("<B>The url value is </B> "+url+<BR>);
19         }
20 }