I am designing for banking application, where user is not allowed to login in particular time.

For example restricted time would be :-

Date : 2022-01-28 to 2022-05-28
Time : 1:00 AM to 4:00 AM
Day  : Mon, Tue, Fri

Restricted duration would be configured in database and I need to do restriction check in Service/DAO layer using Java Code.

I found multiple answers for checking date and time but not for Day.

Can anyone provide consolidated answer for comparing all Date,Time and Day. Thanks for Help!!

CodePudding user response：

Here is one way. Use the DayOfWeek enum in the java.time package.

String[] days = {"Monday", "Tuesday", "Friday"};
LocalDate today = LocalDate.of(2022,1,25);
for (String d : days) {
    System.out.println(DayOfWeek.valueOf(d.toUpperCase())
          .equals(today.getDayOfWeek()));
}

prints

false
true
false

You could also do something like.

String allowed = "MON TUE FRI";
boolean result = allowed.contains(today.getDayOfWeek().name()
           .substring(0,3));
System.out.println(result);

prints

true

CodePudding user response：

tl;dr

You said:

I found multiple answers for checking date and time but not for Day.

LocalDate.now().getDayOfWeek().equals( DayOfWeek.MONDAY )  // Is today Monday?

Time zone

You omitted a crucial element: time zone. I will ignore that if you are certain your software applies only locally to a single time zone. I do not recommend ignoring time zone, but I'll follow your lead on this one.

Record

Define a record to represent your restricted rules set.

record LoginForbidden ( 
    LocalDate startDate , LocalDate endDate , 
    LocalTime startTime , LocalTime endTime , 
    Set< DayOfWeek > dows 
) {}

Database

Retrieve the date and time objects using JDBC 4.2 or later.

LocalDate startDate = myResultSet.getObject( … , LocalDate.class ) ;
…
LocalTime startTime = myResultSet.getObject( … , LocalTime.class ) ;
…

For day-of-week, there is no SQL standard data type. So I suggest you store either 1-7 for Monday-Sunday per ISO 8601, or the all uppercase string name of each DayOfWeek enum object (MONDAY, TUESDAY, etc.). Retrieve as an int or String, respectively. Obtain a DayOfWeek object by calling DayOfWeek.values()[myOrdinalDowNumber-1] or DayOfWeek.valueOf( String ), respectively.

Current moment

Capture the current moment. Doing so requires a time zone. For any given moment, the date and time-of-day both vary around the globe by zone. If you omit the time zone, java.time uses the JVM’s current default time zone.

ZonedDateTime zdt = ZonedDateTime.now() ;

Extract the date portion.

LocalDate today = zdt.toLocalDate() ;

Search your collection of LoginForbidden objects (loginForbiddens) for the current date.

List< LoginForbidden > loginForbiddensForToday = 
        loginForbiddens
        .stream()
        .filter(
            loginForbidden -> ( ! today.isBefore( startDate ) ) && today.isBefore( loginForbidden.endDate ) 
        )
        .toList()
;

We should find exactly one object, I presume. So verify.

if( loginForbiddensForToday.size() != 1 ) { throw new IllegalStateException( "Other than one LoginForbidden found for date: "   today.toString()   ) ; }

If valid, extract the one and only object.

LoginForbidden loginForbiddenForToday = loginForbiddens.get( 0 ) ;

Day of week

Proceed, comparing the day of week.

DayOfWeek dow = today.getDayOfWeek() ;
boolean dayForbidden = loginForbiddenForToday.dows().contains( dow ) ;

Time of day

If the day is forbidden, then move on to compare current time-of-day against the start and stop times.

LocalTime lt = zdt.toLocalTime() ;
boolean denyLogin = ( ! lt.isBefore( loginForbiddenForToday.startTime() ) ) && lt.isBefore( loginForbiddenForToday.endTime() ) ;

This is all rough-draft, untested code. But it should get you pointed in the right direction.