transient 短暂关键字

 

 

package com;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Date;

public class Hello {
	
	public static void main(String args[]) {

		class User implements Serializable
		{
			private Date date= new Date();
			private String username;
			private transient String password;
			public User (String name,String pwd){
				username=name;
				password=pwd;
			}
			public String toString(){
				String pwd=(password==null)?"(n/a)":password;
				return "logon info \n username:"+username+"date:"+date+"pwd:"+pwd;
			}
			

		}
		
		 try {
			User a = new User("A", "B");
			    System.out.println("logon a = " + a);
			    ObjectOutputStream o = new ObjectOutputStream(new FileOutputStream("User.out"));
			    o.writeObject(a);
			    o.close();

			    Thread.sleep(1000); // Delay for 1 second

			    ObjectInputStream in = new ObjectInputStream(new FileInputStream("User.out"));
			    System.out.println("Recovering object at " + new Date());
			    a = (User) in.readObject();
			    System.out.println("logon a = " + a);
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		  }

		




}