by Dinesh Thakur Category: Servlet with MySql Database

This Function Returns numeric exp 1 truncated to exp 2 decimal places.

First i made a database named 'dbase' within the complete reference of mySql(php myAdmin). Then i import all the required java package from java library as program need. Then after i made a class named 'MySqlTRUNCATEFunction' that is been extends the 'HttpServlet'. Then i use to get request from doGet()method the serviceMethod() for output on web browser. Then i loaded all the mandatory drivers for database accessing. After then the next move is to declare variables like i use 'connection' this will use to make a bridge or link between database and the actual code(java code).After then i use 'resultSet' that will be responsible for the getting value from the selected columns and rows. Then i use 'preparedStatement' this will use to executing the selected query like executeQuery as (Select TRUNCATE(4.678,1)). In the last i use doGet() method that will bring the output on the web browser.

To get Output in a manner form i use 'Html' tags, which will appear Output in a 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 MySqlTRUNCATEFunction 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 TRUNCATE(4.678,1)");
                      rs = ps.executeQuery();
                  String title = "Using TRUNCATE 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>MySqlTRUNCATEFunction</servlet-name>
   <servlet-class>MySqlTRUNCATEFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlTRUNCATEFunction</servlet-name>
   <url-pattern>/MySqlTRUNCATEFunction</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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