Android从raw、assets、SD卡中获取资源文件内容

先顺带提一下，raw文件夹中的文件会和project一起经过编译，而assets里面的文件不会~~~  

另外，SD卡获取文件需要权限哦！

   //从res文件夹中的raw 文件夹中获取文件并读取数据
     public String getFromRaw(){
         String result = "";
             try {
                 InputStream in = getResources().openRawResource(R.raw.data);
                 //获取文件的字节数
                 int lenght = in.available();
                 //创建byte数组
                 byte[]  buffer = new byte[lenght];
                 //将文件中的数据读到byte数组中
                 in.read(buffer);
                 result = EncodingUtils.getString(buffer, "UTF-8");
             } catch (Exception e) {
                 e.printStackTrace();
             }
             return result;
     }

     //从assets 文件夹中获取文件并读取数据
     public String getFromAssets(String fileName){
         String result = "";
             try {
                 InputStream in = getResources().getAssets().open(fileName);
                 //获取文件的字节数
                 int lenght = in.available();
                 //创建byte数组
                 byte[]  buffer = new byte[lenght];
                 //将文件中的数据读到byte数组中
                 in.read(buffer);
                 result = EncodingUtils.getString(buffer, "UTF-8");
             } catch (Exception e) {
                 e.printStackTrace();
             }
             return result;
     }
     //从SD卡文件夹中获取文件并读取数据
     public static String readFileAsString(String filePath) throws IOException {
 File f=null;
 f= new File(filePath);//这是对应文件路径全名
         StringBuffer fileData = new StringBuffer();
         InputStream in = null;
   try {
     in = new BufferedInputStream(new FileInputStream(f));
   } catch (FileNotFoundException e3) {
     e3.printStackTrace();
   }
         BufferedReader reader = new BufferedReader(new InputStreamReader(in, "UTF-8"));
         
         char[] buf =  new char[1024];
         int numRead=0;
         while((numRead=reader.read(buf)) != -1){
             String readData = String.valueOf(buf, 0, numRead);
             fileData.append(readData);
         }
         reader.close();
         return fileData.toString();
     }