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();  
            }  
    }