Java 1.8 日期处理更方便 Time 包的LocalDateTime、LocalDate、ZonedDateTime 和Date

    
    //获取当前日期，默认当前时区的
    LocalDateTime localDateTime = LocalDateTime.now();
    System.out.println(localDateTime);
    //按照固定格式转成String
    DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    String dateTime = localDateTime.format(format);
    System.out.println(dateTime);
    //获取年、月、日、小时、分、秒都变成轻松、好记多了
    String dateGet = "Year : " + localDateTime.getYear() + ",month: " + localDateTime.getMonthValue() + 
            ",Day: " + localDateTime.getDayOfMonth() + " hour: " + localDateTime.getHour() +
            ",minute: " + localDateTime.getMinute() + ",second: " + localDateTime.getSecond();
    System.out.println(dateGet);
    //直接转LocalDate，没有时、分、秒
    LocalDate localDate1 = localDateTime.toLocalDate();
    System.out.println(localDate1);
    //LocalDate转String
    String dateformat = localDate1.format(DateTimeFormatter.ofPattern("yyyy/MM/dd"));
    System.out.println(dateformat);
    //LocalDateTime转成ZonedDateTime
    ZoneId zoneId = ZoneId.systemDefault();
    ZonedDateTime zoneDateTime = localDateTime.atZone(zoneId);
    //再转成 java.util.Date()
    Date ndate = Date.from(zoneDateTime.toInstant());
    System.out.println("change to date:");
    System.out.println(ndate);
    //直接获取当前LocalDate
    LocalDate localDate = LocalDate.now();
    System.out.println(localDate);
    
    //直接获取当前
    ZonedDateTime.now();
    Date nowDate = new Date();
    System.out.println(nowDate);