Java 中可序列化和外部化有什么区别

可序列化与外部化的区别

java
import java.io.*;
public class SerializableExample implements Serializable {
    private String name;
    private int age;
    public SerializableExample(String name, int age) {
        this.name = name;
        this.age = age;
    }
    public void serializeObject(String filePath) {
        try {
            FileOutputStream fileOut = new FileOutputStream(filePath);
            ObjectOutputStream out = new ObjectOutputStream(fileOut);
            out.writeObject(this);
            out.close();
            fileOut.close();
            System.out.println("对象已成功序列化并保存到文件中");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static SerializableExample deserializeObject(String filePath) {
        try {
            FileInputStream fileIn = new FileInputStream(filePath);
            ObjectInputStream in = new ObjectInputStream(fileIn);
            SerializableExample obj = (SerializableExample) in.readObject();
            in.close();
            fileIn.close();
            return obj;
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
            return null;
        }
    }
    public static void main(String[] args) {
        SerializableExample obj = new SerializableExample("张三", 25);
        obj.serializeObject("example.ser");
        SerializableExample deserializedObj = SerializableExample.deserializeObject("example.ser");
        System.out.println("反序列化对象的姓名：" + deserializedObj.name);
        System.out.println("反序列化对象的年龄：" + deserializedObj.age);
    }
}

java
import java.io.*;
public class ExternalizableExample implements Externalizable {
    private String name;
    private int age;
    public ExternalizableExample() {
        // 默认构造方法
    }
    public ExternalizableExample(String name, int age) {
        this.name = name;
        this.age = age;
    }
    @Override
    public void writeExternal(ObjectOutput out) throws IOException {
        out.writeObject(name);
        out.writeInt(age);
    }
    @Override
    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        name = (String) in.readObject();
        age = in.readInt();
    }
    public void serializeObject(String filePath) {
        try {
            FileOutputStream fileOut = new FileOutputStream(filePath);
            ObjectOutputStream out = new ObjectOutputStream(fileOut);
            out.writeObject(this);
            out.close();
            fileOut.close();
            System.out.println("对象已成功外部化并保存到文件中");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static ExternalizableExample deserializeObject(String filePath) {
        try {
            FileInputStream fileIn = new FileInputStream(filePath);
            ObjectInputStream in = new ObjectInputStream(fileIn);
            ExternalizableExample obj = (ExternalizableExample) in.readObject();
            in.close();
            fileIn.close();
            return obj;
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
            return null;
        }
    }
    public static void main(String[] args) {
        ExternalizableExample obj = new ExternalizableExample("李四", 30);
        obj.serializeObject("example.dat");
        ExternalizableExample deserializedObj = ExternalizableExample.deserializeObject("example.dat");
        System.out.println("反序列化对象的姓名：" + deserializedObj.name);
        System.out.println("反序列化对象的年龄：" + deserializedObj.age);
    }
}