The function ‘HOUR’ will show the current Hour of system.
I make a table in database named ‘dbase’ with required fields and within the reference of mySql(php myAdmin). Then i import all the required java packages from java library. Then i made class which extends ‘HttpServlet’ named ‘MySqlHourFunc’. I use here serviceMethod() that will use to getting the request from the doGet ()method. Before declaring desired variables i loaded all the required drivers for database accessing. Then After I declare variable like ‘connection’ that will make a link between the database and the actual code. Here i declare ‘resultSet’ Also which is been responsible for the fetching value from the columns and rows. I declare ‘preparedStatement’ that will use to executing selected query like executeQuery() as (Select HOUR(now()))).I use doGet()Method that will get Output on the web browser.
While getting the output on the web browser i use ‘HTML’ code and tags that present output in tabular form.
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 MySqlHourFunc 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 HOUR(now()) AS hr");
rs = ps.executeQuery();
String title = "Using HOUR 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>Result</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>MySqlHourFunc</servlet-name>
<servlet-class>MySqlHourFunc</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
<servlet-name>MySqlHourFunc</servlet-name>
<url-pattern>/MySqlHourFunc</url-pattern>
</servlet-mapping>
Dinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular