轉自： http://www.j2medev.com/code/j2se/language/200602/1343.html

import? java.io.FileInputStream;
import? java.io.FileOutputStream;
import? java.io.ObjectInputStream;
import? java.io.ObjectOutputStream;
import? java.io.Serializable;

public?class? CardReader? {
?? public?static? void? main ( String []? args )?{
???? Card3?card?=? new? Card3 ( 12 ,?Card3.SPADES ) ;
???? System.out.println ( "Card?to?write?is:?"? +?card ) ;

???? try? {
?????? FileOutputStream?out?=? new? FileOutputStream ( "card.out" ) ;
?????? ObjectOutputStream?oos?=? new? ObjectOutputStream ( out ) ;
?????? oos.writeObject ( card ) ;
?????? oos.flush () ;
???? }? catch? ( Exception?e )?{
?????? System.out.println ( "Problem?serializing:?"? +?e ) ;
???? }

???? Card3?acard?=? null ;

???? try? {
?????? FileInputStream?in?=? new? FileInputStream ( "card.out" ) ;
?????? ObjectInputStream?ois?=? new? ObjectInputStream ( in ) ;
?????? acard?=? ( Card3 )?( ois.readObject ()) ;
???? }? catch? ( Exception?e )?{
?????? System.out.println ( "Problem?serializing:?"? +?e ) ;
???? }

???? System.out.println ( "Card?read?is:?"? +?acard ) ;

?? }
}

class? Card3? implements? Serializable? {
?? private? int? suit?=?UNASSIGNED;

?? private? int? number?=?UNASSIGNED;

?? public?final?static? int? UNASSIGNED?=?- 1 ;

?? public?final?static? int? DIAMONDS?=? 1 ;

?? public?final?static? int? CLUBS?=? 2 ;

?? public?final?static? int? HEARTS?=? 3 ;

?? public?final?static? int? SPADES?=? 4 ;

?? public?final?static? int? ACE?=? 1 ;

?? public?final?static? int? KING?=? 13 ;

?? public? Card3 ( int? number,? int? suit )?{
???? if? ( isValidNumber ( number ))?{
?????? this .number?=?number;
???? }? else? {
?????? //Error
???? }

???? if? ( isValidSuit ( suit ))?{
?????? this .suit?=?suit;
???? }? else? {
?????? //Error
???? }
?? }

?? public? int? getSuit ()?{
???? return? suit;
?? }

?? public? int? getNumber ()?{
???? return? number;
?? }

?? public?static? boolean? isValidNumber ( int? number )?{
???? if? ( number?>=?ACE?&&?number?<=?KING )?{
?????? return?true ;
???? }? else? {
?????? return?false ;
???? }
?? }

?? public?static? boolean? isValidSuit ( int? suit )?{
???? if? ( suit?>=?DIAMONDS?&&?suit?<=?SPADES )?{
?????? return?true ;
???? }? else? {
?????? return?false ;
???? }
?? }

?? public? boolean? equals ( Object?obj )?{
???? if? ( obj? instanceof? Card3 )?{
?????? Card3?card?=? ( Card3 )? obj;
?????? if? ( card.getNumber ()? ==? this .number?&&?card.getSuit ()? ==? this .suit )?{
???????? return?true ;
?????? }? else? {
???????? return?false ;
?????? }
???? }? else? {
?????? return?false ;
???? }
?? }

?? public? int? hashCode ()?{
???? return? number?*?suit;
?? }

?? public? String?toString ()?{
???? return? numberToString ( this .number )? +? "?of?"? +?suitToString ( this .suit ) ;
?? }

?? public?static? String?numberToString ( int? number )?{
???? String?result?=? "" ;
???? switch? ( number )?{
???? case? ACE:
?????? result?=? "Ace" ;
?????? break ;
???? case? 2 :
?????? result?=? "Two" ;
?????? break ;
???? case? 3 :
?????? result?=? "Three" ;
?????? break ;
???? case? 4 :
?????? result?=? "Four" ;
?????? break ;
???? case? 5 :
?????? result?=? "Five" ;
?????? break ;
???? case? 6 :
?????? result?=? "Six" ;
?????? break ;
???? case? 7 :
?????? result?=? "Seven" ;
?????? break ;
???? case? 8 :
?????? result?=? "Eight" ;
?????? break ;
???? case? 9 :
?????? result?=? "Nine" ;
?????? break ;
???? case? 10 :
?????? result?=? "Ten" ;
?????? break ;
???? case? 11 :
?????? result?=? "Jack" ;
?????? break ;
???? case? 12 :
?????? result?=? "Queen" ;
?????? break ;
???? case? KING:
?????? result?=? "King" ;
?????? break ;
???? case? UNASSIGNED:
?????? result?=? "Invalid?Number" ;
?????? break ;
???? }
???? return? result;
?? }

?? public?static? String?suitToString ( int? suit )?{
???? String?result?=? "" ;
???? switch? ( suit )?{
???? case? DIAMONDS:
?????? result?=? "Diamonds" ;
?????? break ;
???? case? CLUBS:
?????? result?=? "Clubs" ;
?????? break ;
???? case? HEARTS:
?????? result?=? "Hearts" ;
?????? break ;
???? case? SPADES:
?????? result?=? "Spades" ;
?????? break ;
???? case? UNASSIGNED:
?????? result?=? "Invalid?Suit" ;
?????? break ;
???? }
???? return? result;
?? }
}