基本概念：

序列化是將物件狀態轉換為可保持或傳輸的格式的過程。與序列化相對的是反序列化，它將流轉換為物件。這兩個過程結合起來，可以輕鬆地儲存和傳輸資料。

序列化為一般檔案，也序列化為XML檔案（使用XStream）

用於序列化的實體類Person.java 程式碼如下（記得需要實現Serializable介面）：

import java.io.Serializable;

@SuppressWarnings("serial")
public class Person implements Serializable{
    private String name;
    private int age;
    public Person(){
        
    }
    public Person(String str, int n){
        System.out.println("Inside Person's Constructor");
        name = str;
        age = n;
    }
    String getName(){
        return name;
    }
    int getAge(){
        return age;
    }
}
 

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


public class SerializeToFlatFile {
    public static void main(String[] args) {
        SerializeToFlatFile ser = new SerializeToFlatFile();
        ser.savePerson();
        ser.restorePerson();        
    }
    
    public void savePerson(){
        Person myPerson = new Person("Jay",24);
        try {
            FileOutputStream fos = new FileOutputStream("E:\\workspace\\2010_03\\src\\myPerson.txt");
            ObjectOutputStream oos = new ObjectOutputStream(fos);
            System.out.println("Person--Jay,24---Written");
            System.out.println("Name is: "+myPerson.getName());
            System.out.println("Age is: "+myPerson.getAge());
            
            oos.writeObject(myPerson);
            oos.flush();
            oos.close();
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }
    
    public void restorePerson() {
        try {
            FileInputStream fis = new FileInputStream("E:\\workspace\\2010_03\\src\\myPerson.txt");
            ObjectInputStream ois = new ObjectInputStream(fis);
            
            Person myPerson = (Person)ois.readObject();
            System.out.println("\n--------------------\n");
            System.out.println("Person--Jay,24---Restored");
            System.out.println("Name is: "+myPerson.getName());
            System.out.println("Age is: "+myPerson.getAge());
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }
}
 

Age is: 24

控制物件的序列化和反序列化

例項：UserInfo

import java.io.*;   
import java.util.*;   
  
//本程式通過實現Externalizable介面控制物件序列化和反序列   
public class UserInfo implements Externalizable {   
    public String userName;   
    public String userPass;   
    public int userAge;   
  
    public UserInfo(){   
    }   
  
    public UserInfo(String username,String userpass,int userage){   
        this.userName=username;   
        this.userPass=userpass;   
        this.userAge=userage;   
    }   
       
    //當序列化物件時,該方法自動呼叫   
    public void writeExternal(ObjectOutput out) throws IOException{   
        System.out.println("現在執行序列化方法");   
        //可以在序列化時寫非自身的變數   
        Date d=new Date();   
        out.writeObject(d);   
        //只序列化userName,userPass變數   
        out.writeObject(userName);   
        out.writeObject(userPass);   
    }   
  
    //當反序列化物件時,該方法自動呼叫   
    public void readExternal(ObjectInput in) throws IOException,ClassNotFoundException{   
        System.out.println("現在執行反序列化方法");   
        Date d=(Date)in.readObject();   
        System.out.println(d);   
        this.userName=(String)in.readObject();   
        this.userPass=(String)in.readObject();   
    }   
  
    public String toString(){   
        return "使用者名稱: "+this.userName+";密碼："+this.userPass+   
            ";年齡："+this.userAge;   
    }   
}  

import java.io.ObjectOutputStream;   
import java.io.ObjectInputStream;   
import java.io.FileInputStream;   
import java.io.FileOutputStream;   
import java.util.Date;   
import java.lang.management.*;   
public class Test {   
  
  
  
    //序列化物件到檔案   
    public static void serialize(String fileName){   
        try  
        {   
            //建立一個物件輸出流，講物件輸出到檔案   
            ObjectOutputStream out=new ObjectOutputStream(new FileOutputStream(fileName));   
  
            UserInfo user=new UserInfo("renyanwei","888888",20);   
            out.writeObject(user);  //序列化一個會員物件   
  
            out.close();   
        }   
        catch (Exception x)   
        {   
            System.out.println(x.toString());   
        }   
           
    }   
    //從檔案反序列化到物件   
    public static void deserialize(String fileName){   
        try  
        {   
            //建立一個物件輸入流，從檔案讀取物件   
            ObjectInputStream in=new ObjectInputStream(new FileInputStream(fileName));   
  
            //讀取UserInfo物件並呼叫它的toString()方法   
            UserInfo user=(UserInfo)(in.readObject());             
            System.out.println(user.toString());   
  
            in.close();   
        }   
        catch (Exception x)   
        {   
            System.out.println(x.toString());   
        }   
           
    }   
  
    public static void main(String[] args) {       
  
        serialize("D:\\test.txt");   
        System.out.println("序列化完畢");   
           
        deserialize("D:\\test.txt");   
        System.out.println("反序列化完畢");   
    }   
  
}