What is Externalizable interface in Java?

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Pragya Keshap answered on February 4, 2023 Popularity 3/10 Helpfulness 1/10

answer What is Externalizable interface in Java?

What is Externalizable interface in Java?

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Externalizable interface extends Serializable interface in Java. It is

used for giving the Class control over saving and restoring the

contents of its instances.

A class implements methods writeExternal() and readExternal() to

store and restore the object.

class Car implements Externalizable {
    static int age;
    String name;
    int year;
 
    public Car()
    {
        System.out.println("Default Constructor called");
    }
 
    Car(String n, int y)
    {
        this.name = n;
        this.year = y;
        age = 10;
    }
 
    @Override
    public void writeExternal(ObjectOutput out)
        throws IOException
    {
        out.writeObject(name);
        out.writeInt(age);
        out.writeInt(year);
    }
 
    @Override
    public void readExternal(ObjectInput in)
        throws IOException, ClassNotFoundException
    {
        name = (String)in.readObject();
        year = in.readInt();
        age = in.readInt();
    }
 
    @Override public String toString()
    {
        return ("Name: " + name + "\n"
                + "Year: " + year + "\n"
                + "Age: " + age);
    }
}
 
public class ExternExample {
    public static void main(String[] args)
    {
        Car car = new Car("Shubham", 1995);
        Car newcar = null;
 
        // Serialize the car
        try {
            FileOutputStream fo
                = new FileOutputStream("gfg.txt");
            ObjectOutputStream so
                = new ObjectOutputStream(fo);
            so.writeObject(car);
            so.flush();
        }
        catch (Exception e) {
            System.out.println(e);
        }
 
        // Deserialization the car
        try {
            FileInputStream fi
                = new FileInputStream("gfg.txt");
            ObjectInputStream si
                = new ObjectInputStream(fi);
            newcar = (Car)si.readObject();
        }
        catch (Exception e) {
            System.out.println(e);
        }
 
        System.out.println("The original car is:\n" + car);
        System.out.println("The new car is:\n" + newcar);
    }
}

https://www.geeksforgeeks.org/externalizable-interface-java/

Popularity 3/10 Helpfulness 1/10 Language java

Source: Grepper

Tags: externalizable interface java

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Contributed on Feb 04 2023

Pragya Keshap

0 Answers Avg Quality 2/10

What is Externalizable interface in Java?

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