Discuss how object serialization and object deserialization are achieved.

 Object serialization is the process of converting an object in memory into a sequence of bytes that can be stored on disk or transmitted over a network. Object deserialization is the reverse process of converting a sequence of bytes back into an object in memory.

Java provides built-in support for object serialization and deserialization through the java.io.Serializable interface and the ObjectOutputStream and ObjectInputStream classes. To serialize an object, you first need to implement the Serializable interface in your class. This interface is a marker interface, which means that it has no methods, but simply indicates that the class can be serialized. Then, you can use an ObjectOutputStream to write the object to an output stream, which can be a file, a socket, or any other type of stream. Here's an example:

// A sample class to be serialized
public class Person implements Serializable {
    private String name;
    private int age;
    
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
    
    public String getName() {
        return name;
    }
    
    public int getAge() {
        return age;
    }
}
// Serialization example
try {
    Person person = new Person("John", 25);
    FileOutputStream fileOut = new FileOutputStream("person.ser");
    ObjectOutputStream out = new ObjectOutputStream(fileOut);
    out.writeObject(person);
    out.close();
    fileOut.close();
} catch (IOException i) {
    i.printStackTrace();
}

In this example, we create a Person object and write it to a file named person.ser. The ObjectOutputStream writes the object to the file in a binary format.

To deserialize the object, we can use an ObjectInputStream to read the object from the file and convert it back into a Person object in memory. Here's an example:

// Deserialization example
try {
    FileInputStream fileIn = new FileInputStream("person.ser");
    ObjectInputStream in = new ObjectInputStream(fileIn);
    Person person = (Person) in.readObject();
    in.close();
    fileIn.close();
    System.out.println("Name: " + person.getName());
    System.out.println("Age: " + person.getAge());
} catch (IOException i) {
    i.printStackTrace();
} catch (ClassNotFoundException c) {
    c.printStackTrace();
}

In this example, we read the Person object from the person.ser file and cast it to a Person object. The ObjectInputStream handles the conversion from the binary format to a Java object. We then print out the name and age of the person. Note that the ClassNotFoundException can occur if the class of the serialized object is not found in the classpath.