java序列化和反序列化 以及transient的含义

======================================Emoloyee实体类
package JavaHeigth.serializableTest;
import java.io.Serializable;

public class Employee  implements Serializable{
private static final long serialVersionUID = 3593458869057048152L;
public  String name ;
public String address;
public transient int SSN; //不可序列化状态 瞬态
public int number;
public void mailCheck(){
System.out.println("Mailing a check to " +name +"  "+address  );
}
}
======================================序列化
package JavaHeigth.serializableTest;

import java.io.FileOutputStream;
import java.io.ObjectOutputStream;

public class SerializeDemo {
public static void main(String[] args) {
Employee e = new Employee();
e.name="kaige";
e.address="北京海淀";
e.SSN=112233;
e.number=101;
try {
FileOutputStream fos = new FileOutputStream("f://employee.ser");
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(e);
oos.close();
fos.close();
System.out.println("序列化保存在f://employee.ser中");
} catch (Exception e2) {
// TODO: handle exception
System.out.println("异常");
e2.printStackTrace();
}

}
}

=============================反序列化
package JavaHeigth.serializableTest;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;

public class DeserializeDemo {
public static void main(String [] args)
   {
      Employee e = null;
      try
      {
         FileInputStream fileIn = new FileInputStream("f://employee.ser");
         ObjectInputStream in = new ObjectInputStream(fileIn);
         e = (Employee) in.readObject();
         in.close();
         fileIn.close();
      }catch(IOException i)
      {
         i.printStackTrace();
         return;
      }catch(ClassNotFoundException c)
      {
         System.out.println("Employee class not found");
         c.printStackTrace();
         return;
      }
      System.out.println("Deserialized Employee...");
      System.out.println("Name: " + e.name);
      System.out.println("Address: " + e.address);
      System.out.println("SSN: " + e.SSN);
      System.out.println("Number: " + e.number);
   }
}

SSN=0；原因是transient  变量不能被序列化