apache httpclient 未设置基本身份验证凭据

看一下下面的代码：

DefaultHttpClient http = new DefaultHttpClient();
            http.getCredentialsProvider().setCredentials(
                        new AuthScope(AuthScope.ANY_HOST, AuthScope.ANY_PORT), 
                        new UsernamePasswordCredentials( 
                                                Configuration.username, 
                                                Configuration.developerKey ) );

            HttpPost post = new HttpPost(strURL);
            StringEntity entity = new StringEntity( ac.toXMLString() );
            entity.setContentType("text/xml");
            post.setEntity( entity );
            org.apache.http.HttpResponse response = http.execute( post );

它不会产生任何错误。然而，来自服务器的响应我得到“无授权标头”。使用 Wireshark 检查请求发现确实没有基本身份验证集。

这怎么可能？

好的，默认情况下基本身份验证是关闭的。然而，启用它太复杂了（link https://stackoverflow.com/questions/2014700/preemptive-basic-authentication-with-apache-httpclient-4）。因此，可以使用这段代码，它工作得很好：

DefaultHttpClient http = new DefaultHttpClient();
HttpPost post = new HttpPost(strURL);
UsernamePasswordCredentials creds = new UsernamePasswordCredentials(
                    Configuration.username, 
                    Configuration.developerKey);
post.addHeader( BasicScheme.authenticate(creds,"US-ASCII",false) );
StringEntity entity = new StringEntity( ac.toXMLString() );
entity.setContentType("text/xml");
post.setEntity( entity );
org.apache.http.HttpResponse response = http.execute( post );