Please give explanation for below 3 statements and when to use them in jsp?

Question

response.setHeader("Cache-Control","no-store"); 
response.setHeader("Pragma","no-cache"); 
response.setDateHeader ("Expires", 0);

When you dont want browser to cache your page, see this link http://www.i18nguy.com/markup/metatags.html — mprabhat, May 25 '12 at 06:09
use the terms inside the quotes for a web search. Come back with a more detailed question if necessary — Jens Schauder, May 25 '12 at 06:11

score 0 · Answer 1 · answered May 25 '12 at 06:13

These cache control settings can be used for pages that you do not want the contents of stored locally by the browser. Most web developers DO NOT want to use these because they may negatively impact performance. Examples of when you may want to use it is when you have extensive, dynamic resources.

The expires tag tells the browser that the page expires after being rendered. "Setting EXPIRES to 0 may thus be used to force a modification check at each visit."

can you accept it by clicking the check mark if you like it? — Orbiting Eden, May 25 '12 at 06:37

score 0 · Accepted Answer · edited May 23 '17 at 11:56

You need to set the appropriate HTTP header attributes to prevent the dynamic content output by the JSP page from being cached by the browser. You can do this by executing the following scriptlet at the beginning of your JSP pages to prevent them from being cached at the browser. You need both the statements to take care of some of the older browser versions.

<%
response.setHeader("Cache-Control","no-cache"); //HTTP 1.1
response.setHeader("Pragma","no-cache"); //HTTP 1.0
response.setDateHeader ("Expires", 0); //prevents caching at the proxy server
%>

The same effect can be achieved by using meta tags in the HTML header:

<meta http-equiv="Pragma" content="no-cache">
 <meta http-equiv="Cache-Control" content="no-cache">
 <meta http-equiv="Expires" content="Thu, 01 Dec 2011 00:00:00 GMT">

You can refer here for more information.

Please give explanation for below 3 statements and when to use them in jsp?

2 Answers2