JAVA HTTP连接（HttpURLConnection）中使用代理（Proxy）及其验证(Authentication)

public static void main(String[] args) {
        // TODO Auto-generated method stub
         try {
                URL url = new URL("http://www.baidu.com");
                // 创建代理服务器
                InetSocketAddress addr = new InetSocketAddress("172.21.1.8",80);
                Proxy proxy = new Proxy(Proxy.Type.HTTP, addr); // http 代理
                URLConnection conn = url.openConnection(proxy);  

                    //以下三行是在需要验证时，输入帐号密码信息
                String headerkey = "Proxy-Authorization";
                String headerValue = "Basic "+Base64.encodeToString("atco:atco".getBytes(), false); //帐号密码用:隔开，base64加密方式
                conn.setRequestProperty(headerkey, headerValue);  

                InputStream in = conn.getInputStream();
                // InputStream in = url.openStream();
                String s = IOUtils.toString(in, "utf-8");
                System.out.println(s);
            } catch (Exception e) {
                e.printStackTrace();
            }
    }