| Types java app |
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| Data Types and Operators |
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| (Primitive Data Types) |
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| (Non-Primitive Data Types) |
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| Control Flow Statements |
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| Conditional Statements |
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| Looping Statements |
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| Branching Statements |
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| Object-Oriented Programming (OOP) |
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| Classes and Objects |
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| Inheritance |
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| Polymorphism |
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| Encapsulation |
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| Abstraction |
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| Exception Handling |
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| Introduction to Exceptions |
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| Collections Framework |
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| Overview of Collections |
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| Commonly Used Collections |
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| Iterators |
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| Java I/O |
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| File Handling |
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| Serialization |
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| Multithreading |
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| Introduction to Threads |
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| Thread Synchronization |
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| GUI Programming with Swing |
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| Introduction to Swing |
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| Event Handling |
|---|
| Advanced Topics |
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| Java Database Connectivity (JDBC) |
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| JAVA CODE |
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Java Basics
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Working with Objects
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Arrays, Conditionals, and Loops
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Creating Classes and Applications in Java
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More About Methods
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Java Applet Basics
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Graphics, Fonts, and Color
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Simple Animation and Threads
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More Animation, Images, and Sound
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Managing Simple Events and Interactivity
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Creating User Interfaces with the awt
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Windows, Networking, and Other Tidbits
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Modifiers, Access Control, and Class Design
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Packages and Interfaces
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Exceptions
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Multithreading
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Streams and I/O
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Using Native Methods and Libraries
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Under the Hood
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Java Programming Tools
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Working with Data Structures in Java
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Advanced Animation and Media
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Fun with Image Filters
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Client/Server Networking in Java
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Emerging Technologies
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appendix A :- Language Summary
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appendix B :- Class Hierarchy Diagrams
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appendix C The Java Class Library
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appendix D Bytecodes Reference
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appendix E java.applet Package Reference
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appendix F java.awt Package Reference
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appendix G java.awt.image Package Reference
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appendix H java.awt.peer Package Reference
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appendix I java.io Package Reference
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appendix J java.lang Package Reference
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appendix K java.net Package Reference
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appendix L java.util Package Reference
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The Serializable interface in Java is a marker interface (an interface with no methods) used to enable serialization of an object. Serialization is the process of converting an object’s state to a byte stream, thereby enabling the object to be easily saved to persistent storage or transmitted over a network. Deserialization is the reverse process, where the byte stream is converted back into a copy of the object.
Key Points about Serializable Interface
Marker Interface:
Serializableis a marker interface, meaning it has no methods to implement. Its purpose is to signal to the Java runtime that the class can be serialized.Default Serialization Mechanism: By implementing the
Serializableinterface, a class is indicating that it can be serialized using Java’s built-in serialization mechanism.Serialization and Deserialization Process: During serialization, the
ObjectOutputStreamis used to write the object’s state to an output stream. During deserialization, theObjectInputStreamis used to read the object’s state from an input stream.transient Keyword: Fields marked as
transientare not serialized. This is useful for fields that contain sensitive information or fields that are derived from other fields and don’t need to be stored.serialVersionUID: This is a unique identifier for each class. It is used during deserialization to ensure that a loaded class corresponds exactly to a serialized object. If the class changes after the object was serialized, deserialization will fail unless
serialVersionUIDis defined explicitly and matches.
Example
Let’s look at a simple example to illustrate the use of the Serializable interface.
Defining a Serializable Class
import java.io.Serializable;
public class Person implements Serializable {
private static final long serialVersionUID = 1L; // Optional but recommended
private String name;
private int age;
private transient String password; // This field will not be serialized
public Person(String name, int age, String password) {
this.name = name;
this.age = age;
this.password = password;
}
@Override
public String toString() {
return "Person{name='" + name + '\'' + ", age=" + age + ", password='" + password + '\'' + '}';
}
// Getters and setters...
}
Serializing an Object
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
public class SerializeDemo {
public static void main(String[] args) {
Person person = new Person("John Doe", 30, "secretPassword");
try (FileOutputStream fileOut = new FileOutputStream("person.ser");
ObjectOutputStream out = new ObjectOutputStream(fileOut)) {
out.writeObject(person);
System.out.println("Serialized data is saved in person.ser");
} catch (IOException i) {
i.printStackTrace();
}
}
}
Deserializing an Object
import java.io.FileInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
public class DeserializeDemo {
public static void main(String[] args) {
Person person = null;
try (FileInputStream fileIn = new FileInputStream("person.ser");
ObjectInputStream in = new ObjectInputStream(fileIn)) {
person = (Person) in.readObject();
} catch (IOException | ClassNotFoundException i) {
i.printStackTrace();
}
System.out.println("Deserialized Person...");
System.out.println(person);
}
}
Explanation
Defining a Serializable Class: The
Personclass implementsSerializableand has aserialVersionUIDto ensure compatibility during deserialization. Thepasswordfield is marked astransientand will not be serialized.Serializing an Object: The
SerializeDemoclass creates an instance ofPersonand writes it to a file namedperson.serusingObjectOutputStream.Deserializing an Object: The
DeserializeDemoclass reads theperson.serfile and reconstructs thePersonobject usingObjectInputStream. Thepasswordfield will benullbecause it was marked astransient.
This example demonstrates the basic use of the Serializable interface to save and restore an object’s state.
