title: preemptive authentication why
body: <p>Why preemptive authentication required ?</p>
  
  <p>System.setProperty("httpclient.authentication.preemptive", "true");</p>
  
  <p>I had written web services access client program in java. Where we were setting username and password in call object and that was working perfectly.</p>
  
  <p>Recently, our service provider made some changes at their side and after that they were not receiving username &amp; password in web service call and as they were not receiving username &amp; passwod so we were not able to connect to their (provider) service.</p>
  
  <p>Then i did googling and found about preemptive authentication.
  While calling web services we set "httpclient.authentication.preemptive" as "true" - System.setProperty("httpclient.authentication.preemptive", "true"); , then we are able to receive responses from our service provider.</p>
  
  <p>When we remove System.setProperty("httpclient.authentication.preemptive", "true"); line then we are not able to connect to their services.</p>