深入探索Java对象的序列化

import java.io.*; 

/** 
* Java对象的序列化测试 
* File: ObjectStreamTest.java 
* User: leizhimin 
* Date: 2008-3-12 20:41:43 
*/ 
public  class ObjectStreamTest { 
     public  static  void main(String args[]) { 
        testObjectSeri(); 
        testObjectInSeri(); 

    } 

     /** 
     * 对象序列化测试 
     */ 
     public  static  void testObjectSeri() { 
        Person person =  new Person( "熔岩",  "341022225562156",  "lavasoft"); 
        FileOutputStream fos =  null; 
        ObjectOutputStream oos =  null; 
         try { 
            fos =  new FileOutputStream( "Q:\\study\\java5study\\src\\io\\person.dat"); 
            oos =  new ObjectOutputStream(fos); 
            oos.writeObject(person); 
        }  catch (FileNotFoundException e) { 
            System.out.println( "找不到指定的文件！"); 
            e.printStackTrace(); 
        }  catch (IOException e) { 
            e.printStackTrace(); 
        }  finally { 
             try { 
                oos.flush(); 
                oos.close(); 
            }  catch (IOException e) { 
                e.printStackTrace(); 
            } 
        } 
    } 

     /** 
     * 对象反序列化测试 
     */ 
     public  static  void testObjectInSeri() { 
        FileInputStream fis =  null; 
        ObjectInputStream ois =  null; 
        Person person =  null; 
         try { 
            fis =  new FileInputStream( "Q:\\study\\java5study\\src\\io\\person.dat"); 
            ois =  new ObjectInputStream(fis); 
            person = (Person) ois.readObject(); 
        }  catch (FileNotFoundException e) { 
            e.printStackTrace(); 
        }  catch (IOException e) { 
            e.printStackTrace(); 
        }  catch (ClassNotFoundException e) { 
            e.printStackTrace(); 
        }  finally { 
             try { 
                ois.close(); 
            }  catch (IOException e) { 
                e.printStackTrace(); 
            } 
        } 

        System.out.println(person.toString()); 
    } 
} 

/** 
* 测试序列化所用的类 
*/ 
class Person  implements Serializable { 
     private String username; 
     private String cardNumber; 
     private  transient String password; 

     public Person(String username, String cardNumber, String password) { 
         this.username = username; 
         this.cardNumber = cardNumber; 
         this.password = password; 
    } 

     public String getUsername() { 
         return username; 
    } 

     public  void setUsername(String username) { 
         this.username = username; 
    } 

     public String getCardNumber() { 
         return cardNumber; 
    } 

     public  void setCardNumber(String cardNumber) { 
         this.cardNumber = cardNumber; 
    } 

     public String getPassword() { 
         return password; 
    } 

     public  void setPassword(String password) { 
         this.password = password; 
    } 

     public String toString() { 
        StringBuffer sb =  new StringBuffer( this.getClass().getName()); 
        sb.append( "["); 
        sb.append( "\n\t"); 
        sb.append( "username=" +  this.username); 
        sb.append( "\n\t"); 
        sb.append( "cardNumber=" +  this.cardNumber); 
        sb.append( "\n\t"); 
        sb.append( "password=" +  this.password); 
        sb.append( "]"); 
         return sb.toString(); 
    } 
}

io.Person[ 
    username=熔岩 
    cardNumber=341022225562156 
    password= null] 

Process finished with exit code 0 

序列化运行时使用一个称为 serialVersionUID 的版本号与每个可序列化类相关联，该序列号在反序列化过程中用于验证序列化对象的发送者和接收者是否为该对象加载了与序列化兼容的类。如果接收者加载的该对象的类的 serialVersionUID 与对应的发送者的类的版本号不同，则反序列化将会导致  InvalidClassException 。可序列化类可以通过声明名为  "serialVersionUID"  的字段（该字段必须是静态 (static)、最终 (final) 的  long  型字段）显式声明其自己的 serialVersionUID：