// The MIT License (MIT)

//

// Copyright (c) 2018 Robert C. Seacord

//

// Permission is hereby granted, free of charge, to any person obtaining a copy

// of this software and associated documentation files (the "Software"), to deal

// in the Software without restriction, including without limitation the rights

// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

// copies of the Software, and to permit persons to whom the Software is

// furnished to do so, subject to the following conditions:

//

// The above copyright notice and this permission notice shall be included in all

// copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

// SOFTWARE.

package ser08j;

import java.io.IOException;

import java.io.InvalidObjectException;

import java.io.ObjectInputStream;

import java.io.Serializable;

import java.util.Date;

public final class Period implements Serializable {

private static final long serialVersionUID = 4933289900620142386L;

private Date start;

private Date end;

/**

* @param start

* the beginning of the period

* @param end

* the end of the period; must not precede start

* @throws IllegalArgumentException

* if start is after end

* @throws NullPointerException

* if start or end is null

*/

public Period(Date start, Date end) {

// Make defensive copies of each mutable constructor parameter and

// use the copies in place of the originals

this.start = new Date(start.getTime());

this.end = new Date(end.getTime());

// Throw exception if arguments violate object invariant

if (this.start.compareTo(this.end) > 0)

throw new IllegalArgumentException(start + " after " + end);

}

public Date start() {

// Do not return references to private mutable class members

return new Date(this.start.getTime());

}

public Date end() {

// Do not return references to private mutable class members

return new Date(this.end.getTime());

}

@Override

public String toString() {

return this.start + " - " + this.end;

}

@SuppressWarnings("deprecation")

public static void main(String[] args) {

Date start = new Date();

Date end = new Date();

Period p = new Period(start, end);

Date pEnd = p.end();

// Let's turn back the clock

pEnd.setYear(78);

System.out.println(p);

// Bring back the 60s!

pEnd.setYear(69);

System.out.println(p);

} // end main()

} // end Serializable class Period

// readObject method with defensive copying and validity checking

// This will defend against BogusPeriod and MutablePeriod attacks.

//private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {

// java.io.ObjectInputStream.GetField fields = ois.readFields();

//

// // Defensively copy mutable fields

// Date tempDate = ((Date) fields.get("start", new Date()));

// this.start = new Date(tempDate.getTime());

// tempDate = ((Date) fields.get("end", new Date()));

// this.end = new Date(tempDate.getTime());

//

// // Check that our invariants are satisfied

// if (this.start.compareTo(this.end) > 0)

// throw new InvalidObjectException(this.start + " after " + this.end);

//}