Serializable 序列化为文件

package test;

import java.io.File;

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;

public class Run {

    public static void main(String[] args) throws Exception {

        String personName = "Xiaoming";

        String fileName = "person_file";

        Person person = new Person();

        person.setName(personName);

        se2File(person, fileName); // here1

        // deFromFile(fileName); // here2

    }

    public static void se2File(Person person, String fileName)

            throws FileNotFoundException, IOException {

        System.out.println(new File(fileName).exists());

        ObjectOutputStream oo = new ObjectOutputStream(new FileOutputStream(

                fileName));

        oo.writeObject(person);

        oo.close();

        System.out.println("serialized.");

        System.out.println(new File(fileName).exists());

    }

    public static void deFromFile(String fileName)

            throws FileNotFoundException, IOException, ClassNotFoundException {

        ObjectInputStream oi = new ObjectInputStream(new FileInputStream(

                fileName));

        Person person = (Person) oi.readObject();

        oi.close();

        System.out.println("deserialized.");

        System.out.println("Hi, " + person.getName());

    }

}

class Person implements Serializable {

    // private static final long serialVersionUID = 1L; //here4

    private String name;

    // private int age; // here3

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

}

第一步：只保留here1 ，运行。

false

serialized.

true

第二步：只保留here2 ，运行。

deserialized.

Hi, Xiaoming

第三步：只保留here2、here3 ，运行。

Exception in thread "main" java.io.InvalidClassException: test.Person; local class incompatible: stream classdesc serialVersionUID = -, local class serialVersionUID = -

    at java.io.ObjectStreamClass.initNonProxy(Unknown Source)

    at java.io.ObjectInputStream.readNonProxyDesc(Unknown Source)

    at java.io.ObjectInputStream.readClassDesc(Unknown Source)

    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)

    at java.io.ObjectInputStream.readObject0(Unknown Source)

    at java.io.ObjectInputStream.readObject(Unknown Source)

    at test.Run.deFromFile(Run.java:)

    at test.Run.main(Run.java:)

第4步：只保留here1（here4 ），运行。

true

serialized.

true

第5步：只保留here2（here4 ），运行。

deserialized.

Hi, Xiaoming

第6步：只保留here2、here3（here4 ），运行。

deserialized.

Hi, Xiaoming