java - is meta http-equiv value cache control is not supported?

Question

i have this code here on a page:

<!-- no cache headers -->
<meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate" />
<meta http-equiv="Pragma" content="no-cache" />
<meta http-equiv="Expires" content="0" />
<!-- end no cache headers -->

when i go to other page and hit back button of browser (back to the page where this code written), it is still had the cache state of the page. option is, to add PhaseListener but they told me that adding PhaseListener is an additional codes to maintain.
The question is:
1. is meta tag attribute http-equiv value cache-control is still supported in html in all browser?? because when i check in w3school, there is no value cache-control, pragma, and expires for attribute http-equiv.
2. if i add phaseListener what would be the advantage against adding meta tags in every page.?
Thanks ahead

Answer 1

The <meta http-equiv> tags are only used when the HTML file in question is been opened from a non-HTTP resource such as local disk file system (via file:// URI) and not when the HTML file in question is been opened from a real HTTP resource (via http:// URI). Instead, the real HTTP response headers as set via HttpServletResponse#setHeader() are been used.

So, your concrete problem is caused because those <meta http-equiv> tags are ignored.

See also:

• How to control web page caching, across all browsers?
• Avoid back button on JSF web application