Using AuthCache for Apache HttpClient to do pre-emptive authentication.

grabbit/src/main/groovy/com/twcable/grabbit/client/batch/ClientBatchJobExecutionListener.groovy

@@ -20,11 +20,17 @@ import com.twcable.grabbit.jcr.JcrUtil
 import groovy.transform.CompileStatic
 import groovy.util.logging.Slf4j
 import org.apache.http.HttpEntity
+import org.apache.http.HttpHost
 import org.apache.http.HttpResponse
 import org.apache.http.auth.AuthScope
 import org.apache.http.auth.UsernamePasswordCredentials
+import org.apache.http.client.AuthCache
 import org.apache.http.client.CredentialsProvider
+import org.apache.http.client.HttpClient
 import org.apache.http.client.methods.HttpGet
+import org.apache.http.client.protocol.HttpClientContext
+import org.apache.http.impl.auth.BasicScheme
+import org.apache.http.impl.client.BasicAuthCache
 import org.apache.http.impl.client.BasicCredentialsProvider
 import org.apache.http.impl.client.DefaultHttpClient
 import org.apache.sling.jcr.api.SlingRepository
@@ -108,6 +114,24 @@ class ClientBatchJobExecutionListener implements JobExecutionListener {
         client
     }
 
+    /**
+     * Gets a new HttpClientContext for the given HttpRequest. The ClientContext sets up preemptive
+     * authentication using BasicAuthCache
+     * @param get the HttpGet request
+     * @return the HttpClientContext for given HttpRequest
+     */
+    private HttpClientContext getHttpClientContext(HttpGet get) {
+        // Setup preemptive Authentication
+        // Create AuthCache instance
+        AuthCache authCache = new BasicAuthCache()
+        HttpHost host = new HttpHost(get.URI.host, get.URI.port, get.URI.scheme)
+        authCache.put(host, new BasicScheme())
+        // Add AuthCache to the execution context
+        HttpClientContext context = HttpClientContext.create()
+        context.setAuthCache(authCache)
+        return context
+    }
+
     /**
      * Makes a Http Get request to the grab path and returns the response
      * @param jobParameters that contain information like the path, host, port, etc.
@@ -135,7 +159,9 @@ class ClientBatchJobExecutionListener implements JobExecutionListener {
 
         //create the get request
         HttpGet get = new HttpGet(uriBuilder.build())
-        HttpResponse response = getHttpClient(username, password).execute(get)
+        HttpClient client = getHttpClient(username, password)
+        HttpClientContext context = getHttpClientContext(get)
+        HttpResponse response = client.execute(get, context)
         response
     }