Android通过Json实现导入导出

// 导出文件
        private void Export() {
                filePath = null;
 
                // 判断sd卡是否存在
                boolean hasSDCard = Environment.getExternalStorageState().equals(
                                Environment.MEDIA_MOUNTED);
                if (hasSDCard) {
 
                        filePath = Environment.getExternalStorageDirectory().toString()
                                        + File.separator + "hello.txt";
 
                        try {
                                file = new File(Environment.getExternalStorageDirectory(),
                                                "hello.txt");
                                if (file.exists()) {
                                        file.delete();
                                }
                                FileOutputStream outStream = new FileOutputStream(file);
                                listNote = CreateData.getListData();
                                JSONArray jsonArray = new JSONArray();
                                try {
                                        for (int i = 0; i < listNote.size(); i++) {
                                                json = new JSONObject();
                                                Bug.Print("" + listNote.size());
                                                System.out.println("---->" + listNote.size());
                                                json.put("Id", listNote.get(i).getId());
                                                json.put("Colorid", listNote.get(i).getColorid());
                                                json.put("Context", listNote.get(i).getContext());
                                                json.put("Time", listNote.get(i).getTime());
                                                Bug.Print(json.getString("Colorid"));
                                                jsonArray.put(json);
                                        }
                                        String s = jsonArray.toString();
                                        System.out.println(s);
                                        outStream.write(s.getBytes());
                                } catch (JSONException e) {
                                        e.printStackTrace();
 
                                }
                                Toast.makeText(this.owner, "", Toast.LENGTH_LONG).show();
                                outStream.close();
                                file.createNewFile();
 
                        } catch (Exception e) {
                                e.printStackTrace();
                                Bug.Print(e.getMessage());
                        }
                        // 提示框
                        AlertDialog.Builder builder = new Builder(this.owner);
                        builder.setMessage("导出成功");
 
                        builder.setTitle("已将文本文件(hello.txt)输出至SD卡" + file + "目录下");
 
                        builder.setPositiveButton("确认", new OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialog, int which) {
                                        dialog.dismiss();
                                }
                        });
                        builder.create().show();
                }
        }
 
 
 
 
        // 导入文件
        private void Introduction() {
                /*
                  
                 */
                try {
 
                        File urlFile = new File(Environment.getExternalStorageDirectory()
                                        + "/hello.txt");
                        InputStreamReader isr = new InputStreamReader(new FileInputStream(
                                        urlFile), "UTF-8");
                        BufferedReader br = new BufferedReader(isr);
                        str = "";
                        String mimeTypeLine = null;
 
                        while ((mimeTypeLine = br.readLine()) != null) {
                                str = str + mimeTypeLine;
 
                        }
                        System.out.println(str);
                        JSONObject obj = null;
                        JSONArray jsonArray = null;
 
                        jsonArray = new JSONArray(str);
                        for (int i = 0; i < jsonArray.length(); i++) {
                                obj = jsonArray.getJSONObject(i);
 
                                strID = obj.getString("Context");
                                time = obj.getString("Time");
                                colorid = obj.getString("Colorid");
 
                                System.out.println(strID);
                                CreateData.InsetData(new Entity(strID, time, colorid));
                        }
 
                        Log.d("TAG", str);
                } catch (Exception e) {
 
                        Toast.makeText(this.owner, "导入失败", Toast.LENGTH_LONG).show();
                }
        }