The code after second iteration [Mame night(2014/7/10)](http://www.mamezou.com/event/mn_20140710.html)

Scenario2.java

package iteration.second;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class Scenario2 {
	public static void main(String[] args) {
		ParkingArea pa = new ParkingArea(2);
		Parking t1 = pa.checkin(0);
		System.out.println(t1);
		Parking t2 = pa.checkin(1);
		System.out.println(t2);
		Parking t3 = pa.checkin(1);
		System.out.println(t3);
		t2 = pa.checkout(t2);
		System.out.println(t2);
		Parking t4 = pa.checkin(1);
		System.out.println(t4);

		ParkingArea pb = new ParkingArea(1);
		Parking t5 = pb.checkin(0);
		System.out.println(t5);
		Parking t6 = pb.checkin(0);
		System.out.println(t6);
		pb.checkout(t5);
		System.out.println(t5);
	}
}

class ParkingArea {
	int capacity;
	List<ParkingArea> partitions;
	boolean isFree = true;

	ParkingArea(int capacity) {
		this.capacity = capacity;
		if (capacity > 1) {
			partitions = new ArrayList<ParkingArea>();
			for (int i = 0; i < capacity; i++) {
				partitions.add(new ParkingArea(1));
			}
		}
	}

	Parking checkin(int partitionNumber) {
		if (partitions != null) {
			if (partitions.get(partitionNumber).isFree) {
				partitions.get(partitionNumber).isFree = false;
				return new Parking(partitionNumber, new Date());
			} else {
				return null;
			}
		} else {
			if (isFree) {
				this.isFree = false;
				return new Parking(partitionNumber, new Date());
			} else {
				return null;
			}
		}

	}

	Parking checkout(Parking ticket) {
		if (partitions != null) {
			ParkingArea p = partitions.get(ticket.partitionNumber);
			p.isFree = true;
		} else {
			this.isFree = true;
		}
		ticket.outTime = new Date();
		return ticket;
	}

}

class Parking {
	int partitionNumber;
	Date inTime;
	Date outTime;

	Parking(int partitionNumber, Date inTime) {
		this.partitionNumber = partitionNumber;
		this.inTime = inTime;
	}

	@Override
	public String toString() {
		return "partitionNumber=" + partitionNumber + ":inTime=" + inTime
				+ ":outTime=" + outTime;
	}
}