Apache httpclient 4.5.13 preemptive authentication or not

Question

I came across this code, which I am trying to refactor the deprecated usage of DefaultHttpClient to use HttpClientBuilder and trying to replicate the authentication part.

In HttpClientBuilder world I could use preemptive (HttpClientContext.create().setAuthCache(new BasicAuthCache())) or not - setting the credentials provider directly to the builder (httpClientBuilder.setDefaultCredentialsProvider(new BasicCredentialsProvider()))

In here, I don't see this being specified in any way, so I debugged through the httpclient lib, but could not pull out a conclusion for sure. Could you tell me, whether below code is doing a preemptive or a non-preemptive authentication? (As I had to refactor older http client 3.x code, it was very expressive, since there was the .setAuthenticationPreemptive method, which was telling me clearly, what it was)

import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.HttpParams;
import org.apache.http.params.BasicHttpParams;

import org.apache.http.auth.params.AuthParams;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;

import org.apache.http.client.methods.HttpGet;
...

DefaultHttpClient client = new DefaultHttpClient(new BasicHttpParams());

HttpParams params = client.getParams();
AuthParams.setCredentialCharset(params, "UTF-8");

client.getCredentialsProvider()
        .setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("login","passwd"));
...
client.execute(new HttpGet("uri"));

Thanks you!

Answer 1

It looks like the simple answer is: above is an example of a non-preemptive authentication.

Why? Because the only place where the preemptive one is setup is during the processing of the org.apache.http.client.protocol.RequestAuthCache interceptor, which looks for the set up AuthCache, which in above case is not set up.