by Dinesh Thakur Category: Servlet with MySql Database

This Function Will Returns numeric expression rounded to an integer. Can be use to round an expression to a number of decimal points.

First i make a table in database named 'dbase' within the reference of mySql(php myAdmin). Then i import all the required java package from java library. I make a class named 'MySqlROUNDFunction' extends the 'HttpServlet'. I use here serviceMethod() which is use to getting request from the doGet()Method for output. Before activating all the required variable i loaded all the required drivers for the database accessing then after i declare variables like first i declare 'connection'(this variable will act as to create a link between database and the actual code. Here i declare second one is 'resultSet' this will take the responsible for fetching the value from columns and the selected rows. Here i declare one more 'preparedStatement' this will use to executing the selected query like executeQuery() as (Select ROUND(8.98)).I use doGet()Method which will bring the output on the web browser.

To getting output in tabular form on web browser, i used 'HTML' code and the tags for showing output in manner form also.  

import java.io.IOException;

import java.io.PrintWriter;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MySqlROUNDFunction extends HttpServlet
   {
       public void service(HttpServletRequest rq, HttpServletResponse rp)throws IOException, ServletException
        {
             rp.setContentType("text/html");
             PrintWriter disp = rp.getWriter();
             String driver = "com.mysql.jdbc.Driver";
             String url = "jdbc:mysql://localhost/dbase";
             String uid = "root";
             String psw = "root";
             Connection con=null;
             PreparedStatement ps = null;
             ResultSet rs;
             try
              {
                   Class.forName(driver);
                   con = DriverManager.getConnection(url,uid,psw);
                   ps=con.prepareStatement("Select ROUND(8.98)");
                   rs = ps.executeQuery();
               String title = "Using ROUND Function";
                   String docType ="<!doctype html public \"-//w3c//dtd html 4.0 " + "transitional//en\">\n";
               disp.println(docType + "<html>\n" + "<head><title>" + title + "</title></head>\n" +
                   "<body bgcolor=\"#f4efef\">\n" + "<h1 align=\"center\">" + title + "</h1>\n" + "<ul>\n" +
               "<table width=\"50%\" border=\"1\" align=\"center\">\n" + "<th>Value</th>\n"+ "</body> </html>");
                   while(rs.next())
                      {
                           String val = rs.getString(1);
                       disp.println("<tr><td align=\"center\">" + val +"</td></tr>" );  
                      }     
              }       
                       catch(Exception e) 
                          {
                           e.printStackTrace();
                          }
                           disp.close();
        }
                       public void doPost(HttpServletRequest rq,HttpServletResponse rp)throws IOException,ServletException
                                 {
                                     doGet(rq,rp);
                                 }
   }
WEB.xml
 
<servlet>
   <servlet-name>MySqlROUNDFunction</servlet-name>
   <servlet-class>MySqlROUNDFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlROUNDFunction</servlet-name>
   <url-pattern>/MySqlROUNDFunction</url-pattern>
</servlet-mapping>




About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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