1.序列化：

將java物件轉化為位元組序列

2.反序列化：

將位元組序列恢復成java物件

3.序列化是幹什麼的：

1.儲存在記憶體中的物件的狀態

2.方便傳輸，實現物件的位元組序列傳輸，如影象，視訊等

4.實現

java提供兩種方式一種是實現Serializable介面，另一種是實現Exteranlizable介面，使用Serializable時可利用transient關鍵子修飾不需要被反序列化的屬性，使用Exteranlizable介面時需要重寫writeExternal和readExternal方法

user類實現Serializable介面，實際為空介面，作為可反序列化標識

import
 
 java.io.Serializable;

public class User implements Serializable {

    private String Name;

    private int age;

    public String getName() {

        return Name;

    }

    public void setName(String name) {

        Name = name;

    }

 

    public int getAge() {

        return age;

    }

    
 
public void setAge(int age) {

        this.age = age;

    }

    public User(String name, int age) {

        Name = name;

        this.age = age;

    }

}

Exteranlizable類繼承了Serializable需要實現writeExternal和readExternal方法，注意使用此方法時，若類沒有預設建構函式會報錯

import java.io.*;

public class User implements Externalizable {

    
 
private String Name;

    private int age;

 

    public String getName() {

        return Name;

    }

    public void setName(String name) {

        Name = name;

    }

    public int getAge() {

        return age;

    }

    public void setAge(int age) {

        this.age = age;

    }

 

    public User(){

 

    }

    public User(String name, int age) {

        Name = name;

        this.age = age;

    }

    @Override

    public void writeExternal(ObjectOutput out) throws IOException {

        out.writeObject(Name);

        out.writeObject(age);

    }

    @Override

    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {

         Name = (String) in.readObject();

         age  = (int) in.readObject();

    }

}

objectOutputStream物件輸出流 objectInputStream 物件輸入流

FileOutputStream 檔案輸出流 FileInputStream 檔案輸入流

利用兩者將物件的序列化資料寫入檔案，再從檔案中讀取序列化資料利用readObject恢復成物件

test類程式碼如下：

import java.io.*;

public class test {

    public static void main(String[] args) throws IOException,ClassNotFoundException{

        Serialize();

        DeSerializ();

    }

    private static void Serialize() throws IOException {

        FileOutputStream fos = new FileOutputStream("D://java test//Serial//1.txt");

        ObjectOutputStream oos = new ObjectOutputStream(fos);

        User user1=new User("xxx",21);

        oos.writeObject(user1);

        System.out.print(oos);

        oos.flush();

        oos.close();

    }

    private static void DeSerializ() throws IOException, ClassNotFoundException {

        FileInputStream fis=new FileInputStream("D://java test//Serial//1.txt");

        ObjectInputStream ois=new ObjectInputStream(fis);

        System.out.print(ois+"\n");

        User user2=(User) ois.readObject();

        System.out.print(user2.getName()+user2.getAge());

    }

}

執行Serialize()在1.txt中儲存序列化資料

執行DeSerializ()將序列化資料反序列化為物件