by Dinesh Thakur Category: Servlet with MySql Database

This function will return the value that greater from other number or expression.

I made a database first named 'dbase' within the reference of mySql(php myAdmin). Then i import all required java packages from java library. Then i made a class named 'MySqlGREATERTHANFunction' that extends the 'HttpServlet'. I use here service()Method that will bring the request from doGet()method for an output. Then i loaded all the required drivers from database accessing. Here i use to declare some variables as i use 'connection' this will create a link between the database and the java code. The other variable i used to 'resultSet' this will get the value from the desired columns and the rows as well. In the last phase i use 'preparedStatement' that will responsible for executing Selected Query like executeQuery() as (SELECT 8 > 2). I use doGet() method that will use to get result on the web browser.

Now here i use to set 'Html' Code and tags that will present the output in tabular form on the 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 MySqlGREATERTHANFunction 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 8 > 2");
                     rs = ps.executeQuery();
                  String title = "Using GREATER THAN 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>MySqlGREATERTHANFunction</servlet-name>
   <servlet-class>MySqlGREATERTHANFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlGREATERTHANFunction</servlet-name>
   <url-pattern>/MySqlGREATERTHANFunction</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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