文件缓存（配合JSON数组）

 private final static File filefolder=new File("/sdcard/myData");  private final static File filename=new File("/sdcard/myData/tem.txt");  public static boolean writeCache(List<Data> list)  {    if(!filefolder.exists())      filefolder.mkdirs();    try    {      JSONArray array=new JSONArray();      for(int i=0;i<list.size();i++)      {        Data data=list.get(i);        JSONObject ob=new JSONObject();        ob.put("name", data.getName());        ob.put("reason", data.getReason());        array.put(ob);      }      FileWriter fw=new FileWriter(filename);      fw.write(array.toString());      fw.close();    }    catch(Exception e)    {      e.printStackTrace();      return false;    }    return true;  }  public static List<Data> readCache() throws JSONException,IOException  {    if(!filefolder.exists())      filefolder.mkdir();    List<Data> list=new ArrayList<Data>();    if(filename.exists())    {      FileInputStream in=new FileInputStream(filename);      String line=null;      StringBuffer sb=new StringBuffer("");      BufferedReader br=new BufferedReader(new InputStreamReader(in));      while((line=br.readLine())!=null)        sb.append(line);      br.close();      in.close();      JSONArray array=new JSONArray(sb.toString());      for(int i=0;i<array.length();i++)      {        JSONObject ob=new JSONObject();        ob=array.getJSONObject(i);        Data data=new Data();        data.setName(ob.getString("name"));        data.setReason(ob.getString("reason"));        list.add(data);      }    }    return list;  }