2011.12.22 に書いたひどいコード

Fuga.java

package hoge;

import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.NoSuchElementException;

public class Fuga {
    public static Iterable<Date> iterableDays(Date from, Date to) {
        final Date localFrom = from;
        final Date localTo = to;

        return new Iterable<Date>() {
            @Override
            public Iterator<Date> iterator() {
                return new Iterator<Date>() {
                    private Date from;

                    private Date to;

                    private Date current;

                    private Date nextObject;

                    @Override
                    public boolean hasNext() {
                        if (nextObject != null) {
                            return true;
                        }

                        if (this.current == null) {
                            this.from = localFrom;
                            this.to = localTo;
                            current = localFrom;

                        } else {
                            current = nextDay(this.current);
                        }

                        if (current.after(to)) {
                            return false;
                        }

                        nextObject = current;

                        return true;
                    }

                    @Override
                    public Date next() {
                        if (!hasNext()) {
                            throw new NoSuchElementException();
                        }

                        Date result = nextObject;
                        nextObject = null;

                        return result;
                    }

                    @Override
                    public void remove() {
                        throw new UnsupportedOperationException();
                    }
                };
            }
        };
    }

    public static Date nextDay(Date date) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);

        cal.add(Calendar.DAY_OF_MONTH, 1);

        return cal.getTime();
    }
}