Serialize and deserialize an object. Also demonstrates how constructors are invoked on deserialization.

SerializeDeserialize.java

import java.io.*;

/**
 * Serialize and deserialize an object. Also demonstrates how constructors are invoked on deserialization.
 */
public class SerializeDeserialize {

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

        Bar myBar = new Bar();

        System.out.printf("After initialization:%n");
        System.out.printf("%s%n", myBar);

        myBar.a = 3;
        myBar.b = 4;

        System.out.printf("Before serialization:%n");
        System.out.printf("%s%n", myBar);

        System.out.printf("Serializing...%n");
        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("myBar.obj"));
        oos.writeObject(myBar);

        System.out.printf("Deserializing...%n");
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream("myBar.obj"));
        Bar deserializedBar = (Bar) ois.readObject();

        System.out.printf("After deserialization:%n");
        System.out.printf("%s%n", deserializedBar);
    }
}

class Foo {

    int a = 1;

    Foo() {
        System.out.printf("Foo constructor%n");
    }
}

class Bar extends Foo implements Serializable {

    static final long serialVersionUID = 1l;
    
    int b = 2;

    Bar() {
        System.out.printf("Bar constructor%n");
    }

    public String toString() {
        return String.format("a=%d%nb=%d%n", a, b);
    }
}