❮ Jstl Core Param Tag Jstl Function Trim ❯

JSP `Auto Refresh`

Imagine if you need to live broadcast the score of a game, the real-time status of the stock market, or the current foreign exchange allocation, how would you achieve this? Clearly, to implement such real-time functionality, you would have to regularly refresh the page.

JSP provides a mechanism to make this task simpler, allowing the page to refresh automatically at set intervals.

The simplest way to refresh a page is to use the setIntHeader() method of the response object. The signature of this method is as follows:

public void setIntHeader(String header, int headerValue)

This method informs the browser to refresh after a given time, measured in seconds.

Example of an Auto Refresh Program

This example uses the setIntHeader() method to set the refresh header, simulating a digital clock:

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ page import="java.io.*,java.util.*" %>
<html>
<head>
<title>Auto Refresh Example</title>
</head>
<body>

<h2>Auto Refresh Example</h2>
<%
   // Set to refresh every 5 seconds
   response.setIntHeader("Refresh", 5);
   // Get the current time
   Calendar calendar = new GregorianCalendar();
   String am_pm;
   int hour = calendar.get(Calendar.HOUR);
   int minute = calendar.get(Calendar.MINUTE);
   int second = calendar.get(Calendar.SECOND);
   if(calendar.get(Calendar.AM_PM) == 0)
      am_pm = "AM";
   else
      am_pm = "PM";
   String CT = hour+":"+ minute +":"+ second +" "+ am_pm;
   out.println("Current Time is: " + CT + "\n");
%>

</body>
</html>

Save the above code in a file named main.jsp and access it. It will refresh the page every 5 seconds and fetch the current system time. The output will look like this:

Auto Refresh Example

Current Time is: 6:5:36 PM

You can also write a more complex program on your own.

❮ Jstl Core Param Tag Jstl Function Trim ❯

JSP Auto Refresh

Example of an Auto Refresh Program

JSP `Auto Refresh`