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Chapter 7 Generating the Server Response: HTTP Response Headers

Refresh

This header indicates how soon (in seconds) the browser should ask for 

an updated page. For example, to tell the browser to ask for a new copy 

in 30 seconds, you would specify a value of 30 with 

response.setIntHeader("Refresh", 30)

Note that 

Refresh

 does not stipulate continual updates; it just speci 

fies when the next update should be. So, you have to continue to sup 

ply 

Refresh

 in all subsequent responses, and sending a 204 (

No 

Content

) status code stops the browser from reloading further. For an 

example, see Section 7.3 (Persistent Servlet State and Auto Reloading 

Pages).

Instead of having the browser just reload the current page, you can 

specify the page to load. You do this by supplying a semicolon and a 

URL after the refresh time. For example, to tell the browser to go to 

http://host/path

 after 5 seconds, you would do the following.

response.setHeader("Refresh", "5; URL=http://host/path")

This setting is useful for  splash screens,  where an introductory image 

or message is displayed briefly before the real page is loaded.

Note that this header is commonly set by