by Dinesh Thakur Category: Servlet with MySql Database

This Function will Subtracts time.

First i make a table in database named 'dbase' with required fields and values which is under the reference of mySql(php myAdmin). Here i import all mandatory java packages from the java library as program needs. Then after, i make a class named 'MySqlSubTimeFunc' extends 'HttpServlet'. And here i use serviceMethod() which will get request from the doGet()Method for getting output on the web browser. After, i load all the required drivers for accessing database. After, then i declare mandatory variables as i declare 'Connection' this variable does the job to create a link between database and the actual code. The other one i declare is 'resultSet' that will fetch the value from selected column and rows. Now here i declare the 'preparedStatement' that will use to execute the selected query like executeQuery() as (SELECT SUBTIME('2:00:00.0') AS hrago).Here i use the doGet()Method for output on a web browser.

I use 'HTML' code and some of its tags that will provide the output on the web browser in tabular form.

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 MySqlSubTimeFunc 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 SUBTIME('2:00:00.0') AS hrago");
                   rs = ps.executeQuery();
               String title = "Using Sub Time 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>Result</th>\n"+ "</body> </html>");
                   while(rs.next())
                     {
                          String curr = rs.getString(1);
                      disp.println("<tr><td align=\"center\">" + curr +"</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>MySqlSubTimeFunc</servlet-name>
   <servlet-class>MySqlSubTimeFunc</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlSubTimeFunc</servlet-name>
   <url-pattern>/MySqlSubTimeFunc</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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