Re: [squid-users] Java applet loading and caching problems with Squid

On Fri, 17 Dec 2004, Tilmann Haug wrote:

> According to our customer who runs the proxy: "POST
> http://213.160.26.42:65535/tunneler/F_OD-ROX-EV_DE11026194861081899800793
> HTTP/1.1"
> Is that sufficient? Can i get more logging information?

Applet confused about what it is supposed to talk to..

> Is there a general difference in the proxy use for the following
> configuration:
>
> a) proxy use is done in the browser
>
> b) gateways based routing over the proxy?

Yes, the two setups are very different.

'a' is standard, but requires all software used to be proxy aware. The
Java JRE versions have had a long history of various bugs in their proxy
awareness, mostly due to Java mostly living a life of it's own within the
browser. In addition some of the Java security constraints becomes a bit
odd when using a proxy, mostly due to a misplaced concept of
trustworthiness (or lack thereof).

'b' violates specifications, but sometimes makes life easier as
application software (browsers etc) does not need to be proxy aware.

>> Only use the basic http primitives which relies on the browser http
>> implementation, not some Java http implementation ontop of the Java TCP
>> direct network connections.
>
> Very interersting and pretty good advice. ould you be so kind and exlain a
> bit more in detail? Especially the "on top of java section".

Java has multiple methods of accessing the network

   - Broser HTTP primitives, which are supposed to use the browser
functions to access the network.

   - Direct TCP/IP network access, where Java bypasses the browser and
accesses the network stack of the client computer directly.

   - Various protocol implementations ontop of the direct network access,
including a reasonable HTTP client among a lot of other protocol.

Only the first works well via a proxy. Some versions of JRE also manages
to guess the proxy settings when using the Java HTTP client, but this is
often broken as this interface is not intended to be used in this manner
and mostly intended to be used in Java applications (not applets) where
one is not running inside the browser and consequently does not have the
browser available for networking..

As I am not a Java programmer I don't have the exact names of the
different Java interfaces, but it should not be too hard to find. I only
know the capabilities are there.

Regards
Henrik
Received on Fri Dec 17 2004 - 03:53:31 MST