从一个URL下载原始数据，基于byte字节

public static byte[] loadRawDataFromURL(String u) throws Exception {URL url = new URL(u);HttpURLConnection conn = (HttpURLConnection) url.openConnection();InputStream is = conn.getInputStream();BufferedInputStream bis = new BufferedInputStream(is);ByteArrayOutputStream baos = new ByteArrayOutputStream();final int BUFFER_SIZE = 2048;final int EOF = -1;int c;byte[] buf = new byte[BUFFER_SIZE];while (true) {c = bis.read(buf);if (c == EOF)break;baos.write(buf, 0, c);}conn.disconnect();is.close();byte[] data = baos.toByteArray();baos.flush();return data;}