by Dinesh Thakur Category: Servlet with MySql Database

The Function 'FIELD' will return the position of the first argument.

In the first instance of programming i made a database named 'dbase' that within the reference of mySql(php myAdmin).Then i import all the required java packages from java library. Then i made a class named 'MySqlFIELDFunc' extends 'HttpServlet'. I use here service()Method that will getting the request from doGet()Method for output on the web browser. I loaded all the required drivers for database accessing. Here i use variables for database link i use 'connection' this will create a link a between database and the java code. I use 'resultSet' this will use to get the value from the selected columns and the rows. Then i use 'preparedStatement' that will use to executing the query like executeQuery as (Select FIELD('my','call','my','hex','my')). I use here doGet()Method for output on the web browser.

I use here 'HTML' code and some of these tags to present output in the tabular form on the web browser for 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 MySqlFIELDFunc 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 FIELD('my','call','my','hex','my')");
                   rs = ps.executeQuery();
                String title = "Using FIELD 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 Is </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>MySqlFIELDFunc</servlet-name>
   <servlet-class>MySqlFIELDFunc</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlFIELDFunc</servlet-name>
   <url-pattern>/MySqlFIELDFunc</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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