Module page.codeberg.friedolyn.Friedolyn

Package page.codeberg.friedolyn.grades

Class Semester

java.lang.Object

page.codeberg.friedolyn.grades.Semester

All Implemented Interfaces:

Copyable<Semester>

public class Semester
extends Object
implements Copyable<Semester>

Represents a university semester.

Implementation Note:

This class is not a record, because the constructor needs to validate the year and, if invalid, throw an IllegalArgumentException. While the validation could be done in a record as well, we cannot add throws IllegalArgumentException to the record's constructor signature, risking that callers of the constructor will not handle the exception. JavaDoc is not a sufficient replacement here!

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	Semester.SemesterType	When the semester starts and ends.

Field Summary

Fields

Modifier and Type	Field	Description
private final @NonNull Semester.SemesterType	semesterType	Whether the semester takes place in winter or summer.
private final @NonNull Year	year	The year in which the semester takes place.

Constructor Summary

Constructors

Constructor	Description
Semester(@NonNull Semester.SemesterType semesterType, @NonNull Year year)	Constructs a new Semester object.

Method Summary

Modifier and Type	Method	Description
@NonNull Semester	copy()
boolean	equals(Object object)	Checks whether this Semester's fields are equal to the given object's fields.
@NonNull Semester.SemesterType	getSemesterType()
@NonNull Year	getYear()
static @NonNull Semester	parse(@NonNull String semester)	Converts the given string representation of a semester into a Semester object.
@NonNull String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

semesterType

@NonNull
private final @NonNull Semester.SemesterType semesterType

Whether the semester takes place in winter or summer.

year

@NonNull
private final @NonNull Year year

The year in which the semester takes place. In case of a winter semester, this is the year in which the semester begins. (It will end in the following year.)

Constructor Details

Semester

public Semester(@NonNull
 @NonNull Semester.SemesterType semesterType,
 @NonNull
 @NonNull Year year)
         throws IllegalArgumentException

Constructs a new Semester object.

Parameters:

semesterType - The semesterType, indicating whether the semester takes place in winter or summer.

year - The year in which the semester takes place. In case of a winter semester, this is the year in which the semester begins. (It will end in the following year.) Must be between 1990 and one year from now.

Throws:

IllegalArgumentException - If the given year is before 1990 or after one year from now.

Method Details

getSemesterType

@NonNull
public @NonNull Semester.SemesterType getSemesterType()

Returns:

The semesterType, indicating whether the semester takes place in winter or summer.

getYear

@NonNull
public @NonNull Year getYear()

Returns:

The year in which the semester takes place. In case of a winter semester, this is the year in which the semester begins. (It will end in the following year.)

copy

@NonNull
public @NonNull Semester copy()

Specified by:

copy in interface Copyable<Semester>

Returns:

A new Semester reference with the same semesterType and year as this object.

equals

public boolean equals(Object object)

Checks whether this Semester's fields are equal to the given object's fields.

Overrides:

equals in class Object

Parameters:

object - The object to compare this Semester object to.

Returns:

true if the given object is a Semester object and its semesterType and year fields are equal to this object's equivalents, false otherwise.

toString

@NonNull
public @NonNull String toString()

Overrides:

toString in class Object

Returns:

A string representation of this Semester object.

parse

@NonNull
public static @NonNull Semester parse(@NonNull
 @NonNull String semester)
                               throws IllegalArgumentException

Converts the given string representation of a semester into a Semester object.

Parameters:

semester - The string representation of the semester. Must be in the format Sommersemester YY or Wintersemester YY/YY, where YY is a two-digit year. In case of a Winter semester, the first YY is the year the semester starts in (used as this Semester's year), while the second YY is year +1, i.e. the year the semester ends in (ignored). All years must be between 1990 and one year from now.

Returns:

The Semester object represented by the given string.

Throws:

IllegalArgumentException - If the given string does not match the required format or if the year is before 1990 or after one year from now.

Implementation Note:

Will stop working (correctly) in the year 2090, because the method assumes that YY-formatted years between 90 and 99 are in the 20th century.