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[操作系统]文件缓存(配合JSON数组)


1.  写入缓存:建立文件夹,把list集合里面的数组转换为JSON数组,存入文件夹
2.  读取缓存:把JSON数组从文件夹里面读取出来,然后放入list集合,返回list集合

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; }