How do you *unset* Content-Type when using HttpURLConnection ?

Question

Hi people,
I am using HttpURLConnection to set some http headers. It all works fine except that this utility is setting Content-type to text/html even though I cam not coding it to do so. I can overwrite Content-type by setting it to say, a blank, explicitly in the code, but Content-type still appears as a header (eg if I view the headers in a proxy.)
My question is - how do you completely unset Content-Type? Here's the code snippet :
URL url = new URL("http://mymachine-uk.uk.company.com:24331/test.html");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setIfModifiedSince(longdate); // I've set up longdate previously
// set some headers
con.setRequestProperty("Cache-Control","max-age=0");
con.setRequestProperty("User-Agent","Mozilla/5.0");
con.setRequestProperty("Keep-Alive","300");
// I've tried hacking it like this :
// con.setRequestProperty("Content-type",null);
// but that just shows an empty Content-type, rather than get rid of it.
// In a proxy window on port 24331, the three headers set explicitly above
// all show up correctly. But Content-type:text/html is also shown, even though not coded.
// If I fire off the same page request from a browser, Content-type ISN'T set.
// so there must be a way of doing it :-) Help!
thanks.
Edited by: colin_the_aardvark on Feb 24, 2010 1:45 AM

Answer 1

Hi there,
thanks very much for trying this, the background to this is as follows :
I am testing a software server caching product which is giving me weird behaviour; the actions the cache performs are supposed to be based on the various http headers. I am using a debug proxy ("Charles") (limited freeware-for-a-short-period) to see exactly what http headers are being set by the calling browser, or in this case, the java program. I am setting the headers directly in the code above to match what my browser is setting, as revealed by Charles. Trouble is, I'm getting different reponses back: The browser gets a http 304 from the cache and my java program gets a 200, so I have obviously failed to emulate the browser.. and the only difference I can see is that the Conetnt-Type is not set when I call the page from internet explorer, but with my program above, Content-Type is set, to a default of text/html. I want to get rid of it so I have copied the browser http header settings 100%.
- I tried compiling this code and running it from the prompt (outside of development environment) and Content-Type is still showing up. So from what you are saying... if your attempt does not set this.. then it looks like Content-type must be getting set via some other means?
thankyou :-)