package ser07j;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InvalidObjectException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.Serializable;

import java.util.Date;

public final class Period implements Serializable {

private static final long serialVersionUID = 1639369965306260328L;

private final Date start;

private final 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) {

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

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

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

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

}

public Date start() {

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

}

public Date end() {

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

}

@Override

public String toString() {

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

}

// Serialization proxy for Period class

private static class SerializationProxy implements Serializable {

private static final long serialVersionUID = 234098243823485285L;

private final Date start;

private final Date end;

SerializationProxy(Period p) {

// copy argument data without consistency checking or defensive copying

this.start = p.start;

this.end = p.end;

}

// readResolve method for Period.SerializationProxy

private Object readResolve() {

return new Period(this.start, this.end); // Uses public constructor

}

}

// writeReplace method for the serialization proxy pattern

// Method can be copied verbatim into any class with a serialization proxy.

private Object writeReplace() {

return new SerializationProxy(this);

}

// readObject method for the serialization proxy pattern

private void readObject(@SuppressWarnings("unused") ObjectInputStream stream) throws InvalidObjectException {

throw new InvalidObjectException("Proxy required");

}

// The rest of this is to serialize/deserialize

private static Object deserialize(byte[] bytes) throws Exception {

return new ObjectInputStream(new ByteArrayInputStream(bytes)).readObject();

}

private static byte[] serialize(Object o) throws IOException {

try (ByteArrayOutputStream ba = new ByteArrayOutputStream();

ObjectOutputStream oos = new ObjectOutputStream(ba)) {

oos.writeObject(o);

return ba.toByteArray();

}

}

public static void main(String[] args) throws Exception {

Period period = (Period) deserialize(serialize(new Period(new Date(), new Date())));

System.out.println(period.toString());

}

}