This Function Will Returns the name of the month.
We have created database named ‘dbase’. After that, a class is been declared named ‘MySqlMonthNameFunc’ extends the ‘HttpServlet’. With that kind of efforts, we need to define some methods, which do their job for exporting output. After we just declare Service method()(service method does the job of calling doGet method for getting request).Some variables also define as Connection,Resultset,PreparedStatement.Connection variable use to link between database and actual code(FrontEnd and BackEnd).preparedStatement will use to send the query to database like (Select MONTHNAME(now()) AS mn)). This statement will work according to condition it shows. Now the next method executeQuery() will execute desired query and statement. And in the end doGet() method will be used to fetch the result on a web browser.
To get output in tabular form on the web browser I use ‘HTML’ code and some tags.
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 MySqlMonthNameFunc 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 MONTHNAME(now()) AS mn");
rs = ps.executeQuery();
String title = "Using Month Name 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>Month Name</th>\n"+ "</body> </html>");
while(rs.next())
{
String curr = rs.getString(1);
disp.println("<tr><td align=\"center\">" + curr +"</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>MySqlMonthNameFunc</servlet-name>
<servlet-class>MySqlMonthNameFunc</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
<servlet-name>MySqlMonthNameFunc</servlet-name>
<url-pattern>/MySqlMonthNameFunc</url-pattern>
</servlet-mapping>
Dinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular