java 1.7
Files.write(path,list,StandardCharsets.UTF_8,StandardOpenOption.APPEND);
String preTime = Files.readAllLines(path).get(0);
LocalDate date1 = LocalDate.parse(preTime,DateTimeFormatter.BASIC_ISO_DATE);
//如果时间记录存在，取出上一次操作时间+1天
date = date1.plusDays(1);
原文：http://www.cnblogs.com/rocky-AGE-24/p/7273428.html