通过URL流的形式获取数据

resourceUrl = new URL(downloadUrl.toString());
            HttpURLConnection conn = (HttpURLConnection) resourceUrl.openConnection();
           
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setRequestMethod("POST");
            conn.setUseCaches(false);
            conn.setInstanceFollowRedirects(true);
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            conn.setRequestProperty("Charset", "UTF-8");
            conn.connect();
           
            BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream(),"UTF-8"));
            String line = "";
            StringBuffer buf = new StringBuffer();
           
            while((line = reader.readLine()) != null) {
            buf.append(line);
            }