java调用远程url并接收其返回的xml或json

StringBuffer document = new StringBuffer();try{URL url = new URL("http://www.baidu.com");//远程url地址URLConnection conn = url.openConnection();    BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));    String line = null;    while ((line = reader.readLine()) != null)       document.append(line + " ");    reader.close();}catch(MalformedURLException e) {e.printStackTrace(); }catch(IOException e){    e.printStackTrace(); } document.toString();//返回值