What methods do you know for saving object data when restarting the application?

To save object data when restarting an application in Java, several methods can be used:

• Serialization — converting an object into a byte stream and saving it to a file or database.
• Saving to a database — for example, using JDBC or ORM (Hibernate).
• Using file storage — writing data to text or binary files.
• Preferences API — for saving simple settings and parameters.

Example of object serialization:

import java.io.*;

class User implements Serializable {
    String name;
    int age;

    User(String name, int age) {
        this.name = name;
        this.age = age;
    }
}

// Saving the object
try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("user.dat"))) {
    User user = new User("Ivan", 30);
    oos.writeObject(user);
} catch (IOException e) {
    e.printStackTrace();
}

// Loading the object
try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("user.dat"))) {
    User user = (User) ois.readObject();
    System.out.println(user.name + ", " + user.age);
} catch (IOException | ClassNotFoundException e) {
    e.printStackTrace();
}