Deserialization

title: Deserialization in Java description: Byte stream se object wapas banana

Byte stream se object wapas reconstruct karna.

ObjectInputStream — Deserialize karna

java exampleWoHoTech

try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("student.ser"))) {
    Student s = (Student) ois.readObject();
    System.out.println("Deserialized: " + s);
    // password field null hoga — transient tha
} catch (IOException | ClassNotFoundException e) {
    e.printStackTrace();
}

List Deserialize karna

java exampleWoHoTech

try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("students.ser"))) {
    List<Student> students = (List<Student>) ois.readObject();
    students.forEach(System.out::println);
}

Custom Serialization

java exampleWoHoTech

class SecureData implements Serializable {
    private String data;

    private void writeObject(ObjectOutputStream oos) throws IOException {
        oos.defaultWriteObject();
        // Custom: encrypt data before writing
        oos.writeObject(encrypt(data));
    }

    private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
        ois.defaultReadObject();
        // Custom: decrypt on read
        this.data = decrypt((String) ois.readObject());
    }

    private String encrypt(String s) { return "ENC:" + s; }
    private String decrypt(String s) { return s.replace("ENC:", ""); }
}

Important Points

Class Serializable implement karni chahiye
transient fields default value se restore hote hain
static fields serialize nahi hote
Parent class bhi Serializable honi chahiye (ya default constructor)

title: Deserialization in Java description: Byte stream se object wapas banana

Byte stream se object wapas reconstruct karna.

ObjectInputStream — Deserialize karna

java exampleWoHoTech

try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("student.ser"))) {
    Student s = (Student) ois.readObject();
    System.out.println("Deserialized: " + s);
    // password field null hoga — transient tha
} catch (IOException | ClassNotFoundException e) {
    e.printStackTrace();
}

List Deserialize karna

java exampleWoHoTech

try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("students.ser"))) {
    List<Student> students = (List<Student>) ois.readObject();
    students.forEach(System.out::println);
}

Custom Serialization

java exampleWoHoTech

class SecureData implements Serializable {
    private String data;

    private void writeObject(ObjectOutputStream oos) throws IOException {
        oos.defaultWriteObject();
        // Custom: encrypt data before writing
        oos.writeObject(encrypt(data));
    }

    private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
        ois.defaultReadObject();
        // Custom: decrypt on read
        this.data = decrypt((String) ois.readObject());
    }

    private String encrypt(String s) { return "ENC:" + s; }
    private String decrypt(String s) { return s.replace("ENC:", ""); }
}

Important Points

Class Serializable implement karni chahiye
transient fields default value se restore hote hain
static fields serialize nahi hote
Parent class bhi Serializable honi chahiye (ya default constructor)

Deserialization

ObjectInputStream — Deserialize karna

List Deserialize karna

Custom Serialization

Important Points

Continue learning this concept

Deserialization

ObjectInputStream — Deserialize karna

List Deserialize karna

Custom Serialization

Important Points

Continue learning this concept