by Dinesh Thakur Category: Servlet with MySql Database

This Function will Test a value against a Boolean.

First we need to make a table with required fields into a database named 'dbase' within the reference of MySql(Php MyAdmin).First we need to import all the required packages from the java library. Then we will make a class named 'MySqlISNOTFunction', which extends 'HttpServlet'. After then, we define serviceMethod() which will bring the request from doGet()method for Output. Then, we need to declare all the required Drivers for Database linking. Next move will be to declare mandatory variables for accessing the database like Connection variable this variable will make a bridge or link between database and actual code within the help of drivers. The next variable will be the resultSet this will be use to fetch value from the required columns and rows. And the preparedStatement will does the job as it will use to execute the Query like executeQuery() as (SELECT 2 IS NOT UNKNOWN). And in the end the whole criteria goes to doGet()method which will help to getting output on the web browser.

On to the web browser we need to use 'HTML' code and its tags to get Output in Tabular form or in a manner way.

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 MySqlISNOTFunction 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 2 IS NOT UNKNOWN");
                     rs = ps.executeQuery();
                   String title = "Using IS NOT 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>MySqlISNOTFunction</servlet-name>
   <servlet-class>MySqlISNOTFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlISNOTFunction</servlet-name>
   <url-pattern>/MySqlISNOTFunction</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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