getCredentialsProvider() is undefined for the type HttpClient

this.httpclient = new DefaultHttpClient();
this.context = new BasicHttpContext();
this.url = url;
AuthScope authscope=new AuthScope("192.168.1.30", 80);
Credentials credentials=new NTCredentials("liudamao","liudamao","","");
httpclient.getCredentialsProvider().setCredentials(authscope,credentials);
HttpHost proxy = new HttpHost("192.168.1.1", 80);
httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy);

出现getCredentialsProvider() is undefined for the type HttpClient错误~~~~~请教下这是什么情况 --------------------编程问答-------------------- 有没有人知道啊

补充：Java ,  Java SE