by Dinesh Thakur Category: Servlet with MySql Database

This Function will remove leading spaces.

First I made a database named 'dbase' within the reference of mySql(php myAdmin). Then after, i import all java packages from java library as program need. Here I made a class named 'MySqlLEFTRIMFunction', which extends 'HttpServlet'. I use service()Method that will help to getting the request from doGet()Method for output on web browser. Then, i loaded all the required Drivers that will help to accessing Database. After then, i declare variable first i use 'connection' variable that will create a link between database and the actual code (frontEnd and the backEnd). Other variable is 'ResultSet' that will help to fetch value from the columns and rows as required query. The next variable is 'preparedStatement' that will use to executing the selected Query like executeQuery as (Select LTRIM('  JavaMySql').I use doGet()Method in last instance that will bring the output on web browser.

To get output on the web browser i use 'HTML' code and tags that will present the 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 MySqlLEFTRIMFunction 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 LTRIM('  JavaMySql') as ltrm");
                     rs = ps.executeQuery();
                  String title = "Using LTrim 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>MySqlLEFTRIMFunction</servlet-name>
   <servlet-class>MySqlLEFTRIMFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlLEFTRIMFunction</servlet-name>
   <url-pattern>/MySqlLEFTRIMFunction</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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