Java operation time

				// TODO: 2023/3/14 将毫秒值转换为时间
                //Date date=new Date(19090008);//自定义的毫秒值
                Date date=new Date(System.currentTimeMillis());//获取系统当前时间的毫秒值
                SimpleDateFormat simpleDateFormat=new SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.getDefault());
                String dateStr=simpleDateFormat.format(date);
                Log.e("fxHou","毫秒值转为日期="+dateStr);


                // TODO: 2023/3/14 日期转换为毫秒值
                SimpleDateFormat simpleDateFormat1=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.getDefault());
                try {
    
    
                    Date date1=simpleDateFormat1.parse("2020-09-20 09:47:00");
                    Long ms=date1.getTime();
                    Log.e("fxHou","日期转为毫秒="+ms+"毫秒");
                } catch (ParseException e) {
    
    
                    e.printStackTrace();
                }

                // TODO: 2023/3/14 从日期获取星期、年、月、日
                Date date2=new Date(System.currentTimeMillis());//获取系统当前时间的毫秒值
                Calendar calendar=Calendar.getInstance();
                calendar.setTime(date2);
                //星期
                int weekDay = calendar.get(Calendar.DAY_OF_WEEK)-1;
                //年
                int year = calendar.get(Calendar.YEAR);
                //月
                int month = calendar.get(Calendar.MONTH)+1;
                //日
                int monthDay = calendar.get(Calendar.DAY_OF_MONTH);
                //日
                int hour = calendar.get(Calendar.HOUR_OF_DAY);
                //日
                int minute = calendar.get(Calendar.MINUTE);
                //日
                int second = calendar.get(Calendar.SECOND);
                Log.e("fxHou","星期="+weekDay);
                Log.e("fxHou","年="+year);
                Log.e("fxHou","月="+month);
                Log.e("fxHou","日="+monthDay);
                Log.e("fxHou","时="+hour);
                Log.e("fxHou","分="+minute);
                Log.e("fxHou","秒="+second);