Period.java

package nextstep.courses.domain;

import java.time.LocalDate;
import java.util.Objects;

public class Period {
    private final LocalDate startDate;
    private final LocalDate endDate;

    public Period(LocalDate startDate, LocalDate endDate) {
        if (endDate.isBefore(startDate) || endDate.isEqual(startDate)) {
            throw new IllegalArgumentException("종료일은 시작일보다 이후여야 합니다.");
        }
        this.startDate = startDate;
        this.endDate = endDate;
    }

    public LocalDate getStartDate() {
        return startDate;
    }

    public LocalDate getEndDate() {
        return endDate;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (!(o instanceof Period)) return false;
        Period period = (Period) o;
        return Objects.equals(startDate, period.startDate) &&
                Objects.equals(endDate, period.endDate);
    }

    @Override
    public int hashCode() {
        return Objects.hash(startDate, endDate);
    }
}