by Dinesh Thakur Category: Servlet with MySql Database

This Function will return the Randomly Integer Value.

 First i made a table in database named 'dbase' within the reference of mySql(php myAdmin). Then after, I import all the java packages from java library. I made a class named 'MySqlRANDFunction', which extends 'HttpServlet'. I use here the method service()Method that will use to getting the request from the doGet()Method for an output on the web browser. I loaded all the required drivers for accessing the database. I use here variables as required as I use 'connection' this variable will create a link between the database and the java code. This variable named 'resultSet' will use to get the value from the selected columns and rows from the selected table as required. After that i use to declare 'preparedStatement' that will use to executing the Selected query like executeQuery as (Select RAND()). I use doGet()Method for getting output on the web browser.

To get the Output in an impressive look i use some tags of 'HTML' Code, which will bring the Output in tabular form on a web browser.

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 MySqlRANDFunction 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 RAND()");
                    rs = ps.executeQuery();
                String title = "Using RANDOM 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>MySqlRANDFunction</servlet-name>
   <servlet-class>MySqlRANDFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlRANDFunction</servlet-name>
   <url-pattern>/MySqlRANDFunction</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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