The Function ‘CHAR’ will return the character for each Integer value.
The firstly i made a table in database named ‘dbase’ with required fields and values in it.i import all the required java packages from the java library.I made a class named ‘MySqlCHARFunc’ which extends the ‘HttpServlet’.after then i use serviceMethod() which will bring the request from doGet()method for output. Then after i loaded all required drivers for the database accessing. I declare some mandatory variable for database connecting like i declare ‘Connection’ (this variable will use to create a link between database and the java code or actual code).the next will be ‘resultSet’ the variable will be responsible for the getting values from required columns and rows. The other one variable will be ‘preparedStatement’ this variable will use to execute the Selected Query like executeQuery() as (Select CHAR(’77’,’87’,’83’,’81’,’76’)).i use doGet()Method which will bring the output on web browser.
On the other hand i use ‘HTML’ code and tags for presenting the output in a tabular form or in a manner way on the web browser.
EXAMPLE
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 MySqlCHARFunc 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 CHAR('77','87','83','81','76')");
rs = ps.executeQuery();
String title = "Using CHAR 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>MySqlCHARFunc</servlet-name>
<servlet-class>MySqlCHARFunc</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
<servlet-name>MySqlCHARFunc</servlet-name>
<url-pattern>/MySqlCHARFunc</url-pattern>
</servlet-mapping>
Dinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular