// 获取当前日期和时间

                Calendar cal = Calendar.getInstance();

                String fileName = cal.get(Calendar.YEAR) + "_" + cal.get(Calendar.MONTH) + "_"

                        + cal.get(Calendar.DAY_OF_MONTH) + ".txt";

                FileWriter fileWriter = new FileWriter(new File(filePath + "/" + fileName), true);

                String log = "restart at: " + cal.get(Calendar.HOUR_OF_DAY) + ":"

                        + cal.get(Calendar.MINUTE) + ":" + cal.get(Calendar.SECOND);

                BufferedWriter bufferWriter = new BufferedWriter(fileWriter);

                // attention 换行需要以下两个一起才会在.txt文件中生效

                bufferWriter.write(log + "\r\n");

                bufferWriter.newLine();

                bufferWriter.close();

                fileWriter.close();