ElvisImpersonator.java

// Stealer attack program, produces two distinct Elvis instances! - Page 310
package org.effectivejava.examples.chapter11.item77;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.ObjectInputStream;

public class ElvisImpersonator {
	// Byte stream could not have come from real Elvis instance!
	private static final byte[] serializedForm = new byte[] { (byte) 0xac,
			(byte) 0xed, 0x00, 0x05, 0x73, 0x72, 0x00, 0x05, 0x45, 0x6c, 0x76,
			0x69, 0x73, (byte) 0x84, (byte) 0xe6, (byte) 0x93, 0x33,
			(byte) 0xc3, (byte) 0xf4, (byte) 0x8b, 0x32, 0x02, 0x00, 0x01,
			0x4c, 0x00, 0x0d, 0x66, 0x61, 0x76, 0x6f, 0x72, 0x69, 0x74, 0x65,
			0x53, 0x6f, 0x6e, 0x67, 0x73, 0x74, 0x00, 0x12, 0x4c, 0x6a, 0x61,
			0x76, 0x61, 0x2f, 0x6c, 0x61, 0x6e, 0x67, 0x2f, 0x4f, 0x62, 0x6a,
			0x65, 0x63, 0x74, 0x3b, 0x78, 0x70, 0x73, 0x72, 0x00, 0x0c, 0x45,
			0x6c, 0x76, 0x69, 0x73, 0x53, 0x74, 0x65, 0x61, 0x6c, 0x65, 0x72,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x01,
			0x4c, 0x00, 0x07, 0x70, 0x61, 0x79, 0x6c, 0x6f, 0x61, 0x64, 0x74,
			0x00, 0x07, 0x4c, 0x45, 0x6c, 0x76, 0x69, 0x73, 0x3b, 0x78, 0x70,
			0x71, 0x00, 0x7e, 0x00, 0x02 };

	public static void main(String[] args) {
		// Initializes ElvisStealer.impersonator and returns
		// the real Elvis (which is Elvis.INSTANCE)
		Elvis elvis = (Elvis) deserialize(serializedForm);
		Elvis impersonator = ElvisStealer.impersonator;

		elvis.printFavorites();
		impersonator.printFavorites();
	}

	// Returns the object with the specified serialized form
	private static Object deserialize(byte[] sf) {
		try {
			InputStream is = new ByteArrayInputStream(sf);
			ObjectInputStream ois = new ObjectInputStream(is);
			return ois.readObject();
		} catch (Exception e) {
			throw new IllegalArgumentException(e);
		}
	}
}