public static void readContentFromChunkedPost() throws IOException {
        URL postUrl = new URL(POST_URL);
        HttpURLConnection connection = (HttpURLConnection) postUrl
                .openConnection();
        connection.setDoOutput(true);
        connection.setDoInput(true);
        connection.setRequestMethod("POST");
        connection.setUseCaches(false);
        connection.setInstanceFollowRedirects(true);
        connection.setRequestProperty("Content-Type",
                "application/x-www-form-urlencoded");
        /*
         * 与readContentFromPost()最大的不同，设置了块大小为5字节
         */
        connection.setChunkedStreamingMode(5);
        connection.connect();
        /*
         * 注意，下面的getOutputStream函数工作方式于在readContentFromPost()里面的不同
         * 在readContentFromPost()里面该函数仍在准备http request，没有向服务器发送任何数据
         * 而在这里由于设置了ChunkedStreamingMode，getOutputStream函数会根据connect之前的配置
         * 生成http request头，先发送到服务器。
         */
        DataOutputStream out = new DataOutputStream(connection
                .getOutputStream());
        String content = "firstname=" + URLEncoder.encode("一个大肥人                                                                               " +
                "                                          " +
                "asdfasfdasfasdfaasdfasdfasdfdasfs", "utf-8");
        out.writeBytes(content); 
 
        out.flush();
        out.close(); // 到此时服务器已经收到了完整的http request了，而在readContentFromPost()函数里，要等到下一句服务器才能收到http请求。
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                connection.getInputStream()));
 
        out.flush();
        out.close(); // flush and close
        String line;
        System.out.println("=============================");
        System.out.println("Contents of post request");
        System.out.println("=============================");
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }
        System.out.println("=============================");
        System.out.println("Contents of post request ends");
        System.out.println("=============================");
        reader.close();
        connection.disconnect();
    }