//: Blips.java
//////////////////////////////////////////////////
// Copyright (c) Bruce Eckel, 1998
// Source code file from the book "Thinking in Java"
// All rights reserved EXCEPT as allowed by the
// following statements: You can freely use this file
// for your own work (personal or commercial),
// including modifications and distribution in
// executable form only. Permission is granted to use
// this file in classroom situations, including its
// use in presentation materials, as long as the book
// "Thinking in Java" is cited as the source.
// Except in classroom situations, you cannot copy
// and distribute this code; instead, the sole
// distribution point is http://www.BruceEckel.com
// (and official mirror sites) where it is
// freely available. You cannot remove this
// copyright and notice. You cannot distribute
// modified versions of the source code in this
// package. You cannot use this file in printed
// media without the express permission of the
// author. Bruce Eckel makes no representation about
// the suitability of this software for any purpose.
// It is provided "as is" without express or implied
// warranty of any kind, including any implied
// warranty of merchantability, fitness for a
// particular purpose or non-infringement. The entire
// risk as to the quality and performance of the
// software is with you. Bruce Eckel and the
// publisher shall not be liable for any damages
// suffered by you or any third party as a result of
// using or distributing software. In no event will
// Bruce Eckel or the publisher be liable for any
// lost revenue, profit, or data, or for direct,
// indirect, special, consequential, incidental, or
// punitive damages, however caused and regardless of
// the theory of liability, arising out of the use of
// or inability to use software, even if Bruce Eckel
// and the publisher have been advised of the
// possibility of such damages. Should the software
// prove defective, you assume the cost of all
// necessary servicing, repair, or correction. If you
// think you've found an error, please email all
// modified files with clearly commented changes to:
// Bruce@EckelObjects.com. (Please use the same
// address for non-code errors found in the book.)
/////////////////////////////////////////////////
// Simple use of Externalizable & a pitfall
import java.io.*;
import java.util.*;
class Blip1 implements Externalizable {
public Blip1() {
System.out.println("Blip1 Constructor");
}
public void writeExternal(ObjectOutput out)
throws IOException {
System.out.println("Blip1.writeExternal");
}
public void readExternal(ObjectInput in)
throws IOException, ClassNotFoundException {
System.out.println("Blip1.readExternal");
}
}
class Blip2 implements Externalizable {
Blip2() {
System.out.println("Blip2 Constructor");
}
public void writeExternal(ObjectOutput out)
throws IOException {
System.out.println("Blip2.writeExternal");
}
public void readExternal(ObjectInput in)
throws IOException, ClassNotFoundException {
System.out.println("Blip2.readExternal");
}
}
public class Blips {
public static void main(String[] args) {
System.out.println("Constructing objects:");
Blip1 b1 = new Blip1();
Blip2 b2 = new Blip2();
try {
ObjectOutputStream o =
new ObjectOutputStream(
new FileOutputStream("Blips.out"));
System.out.println("Saving objects:");
o.writeObject(b1);
o.writeObject(b2);
o.close();
// Now get them back:
ObjectInputStream in =
new ObjectInputStream(
new FileInputStream("Blips.out"));
System.out.println("Recovering b1:");
b1 = (Blip1)in.readObject();
// OOPS! Throws an exception:
//! System.out.println("Recovering b2:");
//! b2 = (Blip2)in.readObject();
} catch(Exception e) {
e.printStackTrace();
}
}
} ///:~ |