This Function will Subtracts time.
First i make a table in database named ‘dbase’ with required fields and values which is under the reference of mySql(php myAdmin). Here i import all mandatory java packages from the java library as program needs. Then after, i make a class named ‘MySqlSubTimeFunc’ extends ‘HttpServlet’. And here i use serviceMethod() which will get request from the doGet()Method for getting output on the web browser. After, i load all the required drivers for accessing database. After, then i declare mandatory variables as i declare ‘Connection’ this variable does the job to create a link between database and the actual code. The other one i declare is ‘resultSet’ that will fetch the value from selected column and rows. Now here i declare the ‘preparedStatement’ that will use to execute the selected query like executeQuery() as (SELECT SUBTIME(‘2:00:00.0’) AS hrago).Here i use the doGet()Method for output on a web browser.
I use ‘HTML’ code and some of its tags that will provide the output on the web browser 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 MySqlSubTimeFunc 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 SUBTIME('2:00:00.0') AS hrago");
rs = ps.executeQuery();
String title = "Using Sub Time 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>MySqlSubTimeFunc</servlet-name>
<servlet-class>MySqlSubTimeFunc</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
<servlet-name>MySqlSubTimeFunc</servlet-name>
<url-pattern>/MySqlSubTimeFunc</url-pattern>
</servlet-mapping>