private static final String DEVICE_LOG_PATH = "D:\\google_download\\device_log"

// 主方法
private void syncLogToPath(JSONObject propertiesJsonObject) {
 String deviceIotId = propertiesJsonObject.getString(DEVICE_ID_COLUMN);
 String status = propertiesJsonObject.getString(MESSAGE_TYPE);
 int currentIotState = Constants.hcDeviceStatus.get(status);
 String currentDay = DateUtil.format(new Date(), "yyyyMMdd");
 String newFilePath = DEVICE_LOG_PATH + "\\" + currentDay + ".txt";
 File file = new File(DEVICE_LOG_PATH);
  // 判断文件夹是否存在，不存在则创建
 if (!file.getParentFile().exists()) {
  file.getParentFile().mkdirs();
 }
 try {
  file.createNewFile();
 } catch (IOException e) {
  e.printStackTrace();
 }
 try {
  FileWriter fw = new FileWriter(file, true);
  BufferedWriter bw = new BufferedWriter(fw);
  bw.write("kingid");
  bw.flush();
  bw.close();
  fw.close();
 } catch (IOException e) {
  e.printStackTrace();
 }
 try {
  FileReader fr = new FileReader(file);
  BufferedReader bReader = new BufferedReader(fr);
  String string = bReader.readLine();
  System.out.println(string);
 } catch (FileNotFoundException e) {
  e.printStackTrace();
 } catch (IOException e) {
  e.printStackTrace();
 }
}