Selects the proxy server to use, if any, when connecting to the network resource referenced by a URL. A proxy selector is a concrete sub-class of this class and is registered by invoking the
setDefault
method. The currently registered proxy selector can be retrieved by calling
getDefault
method.
When a proxy selector is registered, for instance, a subclass of URLConnection class should call the select
method for each URL request so that the proxy selector can decide if a direct, or proxied connection should be used. The select
method returns an iterator over a collection with the preferred connection approach.
If a connection cannot be established to a proxy (PROXY or SOCKS) servers then the caller should call the proxy selector's connectFailed
method to notify the proxy selector that the proxy server is unavailable.
The default proxy selector does enforce a set of System Properties related to proxy settings.