can i catch the exception when donload with a url which is 404 not found

when the url is not found ,that my app will not response for a while , but i want shutdown the proxy this moment

Start by reproducing the request with a URL that returns 404 and trace how the Java download and proxy layers handle that response. Check whether the exception or failure is exposed to the app, and define done as allowing the app to observe the 404 and shut down the proxy promptly.

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