android 读取SD卡下TXT文件

 File f=null;
  f= new File("/sdcard/cet4hard.txt");//这是对应文件名
  InputStream in = null;
  try {
   in = new BufferedInputStream(new FileInputStream(f));
  } catch (FileNotFoundException e3) {
   // TODO Auto-generated catch block
   e3.printStackTrace();
  }
  BufferedReader br = null;
  try {
   br = new BufferedReader(new InputStreamReader(in, "gb2312"));
  } catch (UnsupportedEncodingException e1) {
   // TODO Auto-generated catch block
   e1.printStackTrace();
  }
  String tmp;

  try {
   while((tmp=br.readLine())!=null){
    //在这对tmp操作
  }
   br.close();
   in.close();
  } catch (IOException e) {
   // TODO Auto-generated catch block
 e.printStackTrace();

  }