Simplify Sniffer initialization and automatically create the default HostsSniffer
Take Sniffer.Builder out to its own top level class. Remove HostsSniffer.Builder and let SnifferBuilder create the default HostsSniffer. This simplifies the Sniffer initialization as the HostsSniffer is not mandatory anymore. It can still be specified though in case the configuration needs to be changed or a different impl has to be used. Also make HostsSniffer an interface.
We throw IOException, which is the exception that is going to be thrown in 99% of the cases. A more generic exception can happen, and if it is a runtime one we just let it bubble up as is, otherwise we wrap it into runtime one so that we don't require to catch Exception everywhere, which seems odd.
Also adjusted javadocs for all performRequest methods
The new method accepts the usual parameters (method, endpoint, params, entity and headers) plus a response listener and an async response consumer. Shortcut methods are also added that don't require params, entity and the async response consumer optional.
There are a few relevant api changes as a consequence of the move to async client that affect sync methods:
- Response doesn't implement Closeable anymore, responses don't need to be closed
- performRequest throws Exception rather than just IOException, as that is the the exception that we get from the FutureCallback#failed method in the async http client
- ssl configuration is a bit simpler, one only needs to call setSSLStrategy from a custom HttpClientConfigCallback, that doesn't end up overridng any other default around connection pooling (it used to happen with the sync client and make ssl configuration more complex)
Relates to #19055
Users wanting to send a request by providing only its method and endpoint, effectively the only two required arguments, shouldn't need to pass in an empty map and a null entity for the body. While at it we can also add a variant to send requests by specifying only method, endpoint and params, but not body. Headers remain a vararg as last argument, so they can always optionally be provided.
Closes#19312
The assumption is HostsSniffer is that all of the arguments have been properly provided and validated through HostsSniffer.Builder, except they weren't, as the scheme didn't have a default value and when not set would cause NPEs down the road. Improved tests to catch this also.
:client ---------> :client:rest
:client-sniffer -> :client:sniffer
:client-test ----> :client:test
This lines the client up with how we do things like modules and
plugins.