解决微信公众号accessToken白名单问题

获取微信公众号accessToken需要服务器ip配置白名单，但部分客户服务器没有固定ip，因而经常会出现因为ip白名单问题而获取不到公众号的accessToken。

解决办法：proxy代理

public String sendGet(String url, String param) {
        String result = "";
        BufferedReader in = null;
        try {
            String urlNameString = url + "?" + param;

            URL realUrl = new URL(urlNameString);

            //proxy代理服务
            String host = "www.baidu.com";//代理服务器域名
            String port = "8080";//端口号
            //InetAddress.getByName(host),通过域名获得ip地址
            InetSocketAddress socketAddress = new InetSocketAddress(InetAddress.getByName(host), port);
            Proxy proxy = new Proxy(Proxy.Type.HTTP,socketAddress);

            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            if (proxy != null) {
                conn = realUrl.openConnection(proxy);
            }
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("Charset", "utf-8");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 建立实际的连接
            conn.connect();

            // 获取所有响应头字段
            Map<String, List<String>> map = conn.getHeaderFields();
            /*
             * // 遍历所有的响应头字段 for (String key : map.keySet()) { log.debug(key +
             * "--->" + map.get(key)); }
             */
            // 定义 BufferedReader输入流来读取URL的响应
            // out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");
            in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            log.debug("发送GET请求失败:" + ExceptionHelper.GetErrInfo(e));
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                log.info(e2.getMessage());
            }
        }
        return result;
    }

补充：

407 Proxy Authentication Required

与401响应类似，只不过客户端必须在代理服务器上进行身份验证。代理服务器必须返回一个 Proxy-Authenticate 用以进行身份询问。客户端可以返回一个 Proxy-Authorization 信息头用以验证。参见RFC 2617。

If your proxy requires authentication it will give you response 407.

In this case you‘ll need the following code:

    Authenticator authenticator = new Authenticator() {

        public PasswordAuthentication getPasswordAuthentication() {
            return (new PasswordAuthentication("user",
                    "password".toCharArray()));
        }
    };
    Authenticator.setDefault(authenticator);

原文地址：https://www.cnblogs.com/TSHHENLIHAI/p/10826441.html