public abstract CacheRequest put (URI uri, URLConnection conn) throws IOException

The protocol handler calls this method after a resource has been retrieved, and the ResponseCache must decide whether or not to store the resource in its cache. If the resource is to be cached, then put() must return a CacheRequest object which contains an OutputStream that the protocol handler will use to write the resource into the cache. If the resource is not to be cached, then put must return null.

Parameters:
uri    a URI used to reference the requested network resource
conn    - a URLConnection instance that is used to fetch the response to be cached

Returns:  a CacheRequest for recording the response to be cached. Null return indicates that the caller does not intend to cache the response.

Exceptions:
IOException    if an I/O error occurs
IllegalArgumentException    if any one of the arguments is null