HttpClient设置代理

HttpClient 4的代理设置方法：

CredentialsProvider credsProvider = new BasicCredentialsProvider();
credsProvider.setCredentials(new AuthScope(<proxy-host>, <proxy-port>),
    new UsernamePasswordCredentials(<proxy-username>, <proxy-password>));
httpClient.setCredentialsProvider(credsProvider);
HttpHost proxy = new HttpHost(<proxy-host>, <proxy-port>, "http");
httpClient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY,proxy);

新版本中已经不使用这种方式，待更新。