public class InvocationBuilderTest { public static void main( String [] args) { Client client = ClientBuilder.newClient(); try { WebTarget webTarget = client.target( "http: //www.google.fr" ); Builder invocationBuilder = webTarget.request(); Invocation getInvocation = invocationBuilder.build( "GET" ); // Request http://www.google.fr with GET method getInvocation.invoke( String .class); // invocationBuilder is supposed to build a new // javax.ws.rs.client.Invocation instance but it does not. invocationBuilder.build( "POST" ); // The previously built getInvocation has become a postInvocation // regardless of the fact that there was no assignation to // getInvocation variable on previous line. Error 405 (Method Not // Allowed) getInvocation.invoke( String .class); } finally { client.close(); } } }