29 - Serialization - Transient - Constructor - Java 1.6.0_18

package serialization2;

import java.io.Serializable;

public class A  {
    int a1 = -1;
    int a2 = -2;
    int a3 = -3;

    A() {
        System.out.println("in A()");
    }
}

package serialization2;

import java.io.Serializable;

public class A1 extends A implements Serializable {

    int a;

    transient int b;

    A1(int a, int b) {

        this.a = a;

        this.b = b;

    }

    public String toString() {

        String aString = Integer.toString(super.a1)

                + " " + Integer.toString(super.a2)

                + " " + Integer.toString(super.a3)

                + " " + Integer.toString(a)

                + " " + Integer.toString(b);

        return aString;

    }

}

package serialization2;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import javax.imageio.stream.FileImageInputStream;

public class Main {

    public static void main(String[] args) throws Exception {

        A1 refA1 = new A1(-1,-2);

        System.out.println("refA1 : " + refA1);

        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("A1.ser"));

        oos.writeObject(refA1);

        System.out.println("reading it back");

        refA1 =(A1)new ObjectInputStream(new FileInputStream("A1.ser")).readObject();

        System.out.println("refA1 : " + refA1);

        

    }

}

If A is not serializable 

run:

in A()

refA1 : -1 -2 -3 -1 -2

reading it back

in A()

refA1 : -1 -2 -3 -1 0

The constructor was called. b is transient and assigned 0.

If a is serializable

run:

in A()

refA1 : -1 -2 -3 -1 -2

reading it back

refA1 : -1 -2 -3 -1 0

The constructor was NOT called. b is still transient and still assigned 0.