android 如何写文件日志到SD卡上..

/**
  * 写文件到sd卡上
  *
  * @param context
  */
 public void writeFileToSD(String context) {

//使用RandomAccessFile 写文件 还是蛮好用的..推荐给大家使用...
  String sdStatus = Environment.getExternalStorageState();
  if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) {
   Log.d("TestFile", "SD card is not avaiable/writeable right now.");
   return;
  }
  try {
   String pathName = "/sdcard/";
   String fileName = "log.txt";
   File path = new File(pathName);
   File file = new File(pathName + fileName);
   if (!path.exists()) {
    Log.d("TestFile", "Create the path:" + pathName);
    path.mkdir();
   }
   if (!file.exists()) {
    Log.d("TestFile", "Create the file:" + fileName);
    file.createNewFile();
   }
   RandomAccessFile raf = new RandomAccessFile(file, "rw");
   raf.seek(file.length());
   raf.write(context.getBytes());
   raf.close();
   //注释的也是写文件..但是每次写入都会把之前的覆盖..
   /*String pathName = "/sdcard/";
   String fileName = "log.txt";
   File path = new File(pathName);
   File file = new File(pathName + fileName);
   if (!path.exists()) {
    Log.d("TestFile", "Create the path:" + pathName);
    path.mkdir();
   }
   if (!file.exists()) {
    Log.d("TestFile", "Create the file:" + fileName);
    file.createNewFile();
   }
   FileOutputStream stream = new FileOutputStream(file);
   String s = context;
   byte[] buf = s.getBytes();
   stream.write(buf);
   stream.close();*/

  } catch (Exception e) {
   Log.e("TestFile", "Error on writeFilToSD.");
  }
 }