This Function will return the string argument, left-padded with the specified string.
First of all i made a database named ‘dbase’ within the reference of mySql(php myAdmin).Here i also import required java packages from java library. Then after i made a class named ‘MySqlLEFTPADFunction’ which extends ‘HttpServlet’. Then i use service()Method that will bring request from the doGet()Method for output. Just before declaring variable i loaded all the required drivers that are necessary for database accessing. Then after i use variable like i use ‘connection’ for creating a link between database and java code. Other i use ‘resultSet’ that will do the required job to fetch value from the selected columns and rows. Other one is ‘preparedStatement’ that will use to executing the selected Query like executeQuery() as (Select LPAD(‘MySql’,5,’!!’). In the last phase i use doGet()Method that will present output on the web browser.
Now i used some kind of ‘HTML’ code and tags that will present the output in a 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 MySqlLEFTPADFunction 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 LPAD('MySql',5,'!!') as lpad");
rs = ps.executeQuery();
String title = "Using LEFTPAD 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>MySqlLEFTPADFunction</servlet-name>
<servlet-class>MySqlLEFTPADFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
<servlet-name>MySqlLEFTPADFunction</servlet-name>
<url-pattern>/MySqlLEFTPADFunction</url-pattern>
</servlet-mapping>
Dinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular