Best Way to determine MimeType from a String?

I have a crawler that downloads pages and tries to parse the HTML. One of the iss开发者_如何学Pythonues I've been facing is how to properly determine what mimetype an HTML file is.

Right now I'm using

is = new ByteArrayInputStream( htmlResult.getBytes( "UTF-8" ) );
mimeType = URLConnection.guessContentTypeFromStream(is);

but it misses sites like this: http://www.artdaily.org/index.asp?int_sec%3D11%26int_new%3D39415 because of the extra space between the doc tag and HTML tag in the source.

Does anyone know a good way to determine if a string is HTML or not? Searching for or some other tag wouldn't necessarily work because of text being embedded in binary files I may come across.

thanks

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Do you have control over the http connection that you crawler uses? Then how about checking the HTTP response header "Content-type". Thats one way to determine the content type. I just did a quick test of the artdaily.com to see if the content type header was sent. And there is one that has a value text/html