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Java Source | 2000-05-25 | 4.4 KB | 127 lines |
- //: Worm.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.)
- /////////////////////////////////////////////////
-
- // Demonstrates object serialization in Java 1.1
- import java.io.*;
-
- class Data implements Serializable {
- private int i;
- Data(int x) { i = x; }
- public String toString() {
- return Integer.toString(i);
- }
- }
-
- public class Worm implements Serializable {
- // Generate a random int value:
- private static int r() {
- return (int)(Math.random() * 10);
- }
- private Data[] d = {
- new Data(r()), new Data(r()), new Data(r())
- };
- private Worm next;
- private char c;
- // Value of i == number of segments
- Worm(int i, char x) {
- System.out.println(" Worm constructor: " + i);
- c = x;
- if(--i > 0)
- next = new Worm(i, (char)(x + 1));
- }
- Worm() {
- System.out.println("Default constructor");
- }
- public String toString() {
- String s = ":" + c + "(";
- for(int i = 0; i < d.length; i++)
- s += d[i].toString();
- s += ")";
- if(next != null)
- s += next.toString();
- return s;
- }
- public static void main(String[] args) {
- Worm w = new Worm(6, 'a');
- System.out.println("w = " + w);
- try {
- ObjectOutputStream out =
- new ObjectOutputStream(
- new FileOutputStream("worm.out"));
- out.writeObject("Worm storage");
- out.writeObject(w);
- out.close(); // Also flushes output
- ObjectInputStream in =
- new ObjectInputStream(
- new FileInputStream("worm.out"));
- String s = (String)in.readObject();
- Worm w2 = (Worm)in.readObject();
- System.out.println(s + ", w2 = " + w2);
- } catch(Exception e) {
- e.printStackTrace();
- }
- try {
- ByteArrayOutputStream bout =
- new ByteArrayOutputStream();
- ObjectOutputStream out =
- new ObjectOutputStream(bout);
- out.writeObject("Worm storage");
- out.writeObject(w);
- out.flush();
- ObjectInputStream in =
- new ObjectInputStream(
- new ByteArrayInputStream(
- bout.toByteArray()));
- String s = (String)in.readObject();
- Worm w3 = (Worm)in.readObject();
- System.out.println(s + ", w3 = " + w3);
- } catch(Exception e) {
- e.printStackTrace();
- }
- }
- } ///:~