序例化-Externalizable 接口

package externalizable.cn;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;
public class ExternalizableDemo {
    public static void main(String[] args) throws Throwable {
        ser();
        dser();    
    }
    //序例化类
    public static void ser() throws Throwable{
        File f = new File("d:"+File.separator+"e.txt");
        OutputStream out = new FileOutputStream(f);
         ObjectOutputStream otp = new ObjectOutputStream(out);
         //void    writeObject(Object obj)   将指定的对象写入 ObjectOutputStream。
         otp.writeObject(new Person("张三",30));
         otp.close();
    }    
    
    //反序例化类
      public static void dser() throws Throwable{
       File f = new File("d:"+File.separator+"e.txt");
       InputStream ip = new FileInputStream(f);
       //new 一个对象输入流
       ObjectInputStream oji = new ObjectInputStream(ip);
       Object object = oji.readObject();
       oji.close();
       System.out.println(object);
      }
}  

package externalizable.cn;

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

/*
 * 接口 Externalizable  用户自己指定序例化的内容
 * public interface Externalizable extends Serializable{
 *  public void    readExternal(ObjectInput in);
 *   public void    writeExternal(ObjectOutput out); 
 * }
 */
public class Person implements Externalizable {
    private String name;
    private int age;
    //无参构造：要实现 Externalizable 接口，必须得有一个无参构造
    public Person(){}
    public Person(String name,int age){
        this.age = age;
        this.name = name;
    }
    public String toString (){
         return "姓名:"+this.name+"，年龄："+this.age;
    }
    //实现两个抽象方法
    public void    readExternal(ObjectInput in) throws IOException{
       try {
        this.name = (String)in.readObject();
        this.age = (int)in.readInt();
    } catch (ClassNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    }
    public void    writeExternal(ObjectOutput out) throws IOException{
        out.writeObject(this.name);
        out.writeInt(this.age);
    }

}