by Dinesh Thakur Category: Servlet with MySql Database

This Function will Returns the sine of numeric expression given in radians.

First i made a database named 'dbase' within the reference of mySql(php myAdmin) with required fields and values in it. Then according to need of program, I import all the java packages from the java library. I create a class named 'MySqlSINFunction',which extends 'HttpServlet'. Then i use serviceMethod() that will bring the request from doGet()Method for output on web browser. After using serviceMethod() i loaded all the required Drivers mandatory for database accessing. Here after i declare variables as first i use 'connection' this will use to create a link between database and the java code. Then i use 'resultSet' this use to get the value from selected columns and rows. And the other one i use is 'preparedStatement' this will use to executing the selected Query like executeQuery() as (Select SIN(1)).I use doGet()Method for output on the web browser.

To make output Impressive i use 'HTML' tags to get 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 MySqlSINFunction 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 SIN(1)");
                    rs = ps.executeQuery();
                String title = "Using SIN 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>MySqlSINFunction</servlet-name>
   <servlet-class>MySqlSINFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlSINFunction</servlet-name>
   <url-pattern>/MySqlSINFunction</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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