. Implement a date class b2. Date. As a constructor parameter expects day, month, and year as int values

exercise sheet 2

Welcome to the Programming in Java Lab.

Task 1. Implement a date class b2. Date. As a constructor parameter expects day, month, and year as int values. A date once set should be immutable. In addition, the standard getter class for reading the data provide day, month, year elements of history. In addition, a formatted string representation of their content can be generated. Don’t forget the standard methods too also implement and realize a “copy constructor”. example:

Datum d1 = new Datum(17, 10, 2022);

System.out.println(d1.fmt()); // 17.10.2022

System.out.format(“%d.%d.%d\n”,

d1.getTag(), d1.getMonat(), d1.getJahr()); // 17.10.2022

System.out.println(d1); // Datum(tag=17, monat=10, jahr=2022)

Datum d2 = new Datum(17, 11, 2022);

System.out.format(“%s\n”, d1.equals(d2)); // false

Datum d3 = new Datum(17, 10, 2022);

System.out.format(“%s\n”, d1.equals(d3)); // true

System.out.format(“%s\n”, d1 == d3); // false

Datum d4 = d1;

System.out.format(“%s\n”, d1 == d4); // true

Set<Datum> set = new HashSet<>();

for (int i = 1; i <= 15; ++i) {

set.add(new Datum(i, 10, 2022));

set.add(new Datum(i + 1, 10, 2022));

set.add(new Datum(i + 2, 10, 2022));

}

System.out.format(“%d\n”, set.size()); // 1

Task 2. Add a method int getWeekday () to the date class returns the current day of the week. The number of the day of the week (0 = Saturday, 1 = Sunday, …, 6 = Friday). To do this, follow the steps below in this order through. If month = 2: increase day by 31.

• If month < 2: set month to 13 and decrease year by 1.
• If month < 8: set k to 3, else to 7.
• If month is even: set k to 5
• Calculate day = ((2000 ((year / 100) % 4) + 10 ((year % 100) – ((year % 100) % 4))
• + ((year % 100) % 4)) + 1000 month + 100k + day) % 7.

The operator stands for multiplication, / means integer division and % of remainder or modulo. Add a new method String getWeekDayString() to the date class, which returns the day of the week as a string. Avoid unnecessary calculations and try to get by without control structures such as if or switch for the string output men. example:

Datum d1 = new Datum(17, 10, 2022);

System.out.print(d1.getWochentag() + “, “);

System.out.println(d1.getWochentagString()); // 2, Montag

for (int i = 0; i < 7; i += 1) {

Datum d = new Datum(17 + i, 10, 2022);

System.out.print(d.getWochentag());

}

System.out.println(); // 2345601

Task 3. A stamp card has a fixed number of fields. With each use, a field is “stamped” with the current date until it is full. Implement class b2. Stamp card that receives the number of stamp fields as a constructor parameter. With the method boolean stamp (date d) the next free field is always “stamped” with the transferred date and true is returned. Of course only if there is still space on the card, otherwise nothing happens and false is returned. With the method boolean cancel (), the last stamp is canceled (we assume that one has stamped by mistake), which can be done several times. True is returned if and only if (gdw) the cancellation was successful. Finally, there is a method int free fields () that returns the number of fields that are still free. The stamp card can be formatted as a string as shown in the example and two stamp cards can be tested against each other for equality. They are exactly the same if both the total number of fields and the stamped fields match in the order and content of the dates they contain. example:

Stempelkarte s1 = new Stempelkarte(5);

Stempelkarte s2 = new Stempelkarte(10);

System.out.format(“%s\n”, s1.equals(s2)); // false

Stempelkarte s3 = new Stempelkarte(5);

System.out.format(“%s\n”, s1.equals(s3)); // true

Datum d1 = new Datum(17, 10, 2022);

s1.abstempeln(d1);

System.out.format(“%s\n”, s1.equals(s3)); // false

s3.abstempeln(d1);

System.out.format(“%s\n”, s1.equals(s3)); // true

s1.abstempeln(new Datum(18, 10, 2022));

System.out.format(“%d\n”, s1.freieFelder()); // 3

System.out.format(“%s\n”, s1.stornieren()); // true

System.out.format(“%s\n”, s1.toString());

// Stempelkarte(5, [17.10.2022, …]-4)

Note 1. For all tasks, see the B2Test file. java a collection of unit tests. Use the quizzes to test your solution to the tasks. If you have read through the entire exercise sheet beforehand, as originally planned, then you can of course also start with the tests.