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Socket (TCP & UDP) communication in Java

Socket communication in Java enables communication between two endpoints over a network. There are two main types of sockets: TCP sockets and UDP sockets. Let's explain both types with examples: TCP Socket Communication: 1. **Server Side**:    - The server creates a `ServerSocket` object to listen for incoming connections on a specific port.    - When a client connects, the server accepts the connection and creates a `Socket` object to communicate with the client.    - The server reads from and writes to the socket's input and output streams to communicate with the client. import java.io.*; import java.net.*; public class TCPServer {     public static void main(String[] args) throws IOException {         ServerSocket serverSocket = new ServerSocket(12345);         System.out.println("Server started. Waiting for client...");         Socket clientSocket = serverSocket.accept();         System.out.println("Client connected.");         BufferedReader in = new Bu

The `try` block in Java

The `try` block in Java is used to enclose the code that may throw an exception. It is followed by one or more `catch` blocks and an optional `finally` block. The `try` block allows you to handle exceptions gracefully by providing a mechanism to catch and handle any exceptions that occur during the execution of the enclosed code. Syntax: try {     // Code that may throw an exception } catch (ExceptionType1 ex1) {     // Code to handle ExceptionType1 } catch (ExceptionType2 ex2) {     // Code to handle ExceptionType2 } finally {     // Cleanup code (optional) } Explanation: - The `try` block encloses the code that you want to monitor for exceptions. - If an exception occurs within the `try` block, the control is transferred to the appropriate `catch` block that matches the type of the thrown exception. - You can have multiple `catch` blocks to handle different types of exceptions. - The `finally` block, if present, is executed regardless of whether an exception occurred or not. It is co

Catching and Handling Exceptions

Catching and handling exceptions is a crucial aspect of Java programming, as it allows developers to gracefully manage unexpected errors and prevent program termination. This is typically achieved using `try`, `catch`, and `finally` blocks. Let's explore each of these blocks and how they are used to catch and handle exceptions: 1. `try` Block: The `try` block contains the code that may potentially throw an exception. It is followed by one or more `catch` blocks to handle specific types of exceptions, or by a `finally` block for cleanup code. 2. `catch` Block: A `catch` block is used to catch and handle exceptions that are thrown within the corresponding `try` block. It specifies the type of exception it can handle and provides code to handle the exception. 3. `finally` Block: The `finally` block is optional and is used to execute cleanup code that should be run whether an exception occurs or not. This block is commonly used to release resources such as file handles or database conn

Exceptions and Errors

Exceptions: Exceptions represent exceptional conditions that can occur during the execution of a program. They can be caused by various factors such as invalid input, network issues, or file not found. Exceptions are further categorized into two types: 1. Checked Exceptions: These are exceptions that are checked at compile time. They are typically recoverable and should be handled by the programmer. Examples include `IOException`, `SQLException`, etc. 2. Unchecked Exceptions (Runtime Exceptions): These are exceptions that are not checked at compile time. They usually indicate programming errors or unexpected conditions. Examples include `NullPointerException`, `ArrayIndexOutOfBoundsException`, etc. Errors: Errors, on the other hand, represent serious problems that are typically beyond the control of the program. They are usually caused by system-level issues or conditions such as out of memory, stack overflow, or hardware failures. Errors are not normally caught or handled by the pro

Comparison between Abstract Class and interface

Abstract classes and interfaces are both key components of object-oriented programming in Java, but they serve different purposes and have distinct characteristics. Here's a comparison between abstract classes and interfaces along with examples and analogies: 1. Purpose:    - Abstract Class: An abstract class is used to define a common base for a group of related classes. It can contain both abstract (unimplemented) methods and concrete (implemented) methods.    - Interface: An interface is used to define a contract for classes that implement it. It contains only method signatures without any implementation. 2. Usage:    - Abstract Class: An abstract class is used when you want to provide a default implementation for some methods while leaving others to be implemented by subclasses. It's suitable for creating a hierarchy of closely related classes.    - Interface: An interface is used when you want to define a set of methods that must be implemented by any class that wants

Understanding of Java Object Class

The `Object` class in Java serves as the root of the class hierarchy. Here are some key points to understand about the `Object` class along with examples: 1. Default Superclass: If a class doesn't extend any other class explicitly, it implicitly inherits from the `Object` class.    public class MyClass {        // MyClass inherits from Object implicitly    } 2. toString() Method: Provides a string representation of the object. It is commonly overridden to return meaningful information about the object.    public class Student {        private String name;        private int age;        // Constructor and other methods...        @Override        public String toString() {            return "Student{name='" + name + "', age=" + age + '}';        }    } 3. equals() Method: Compares two objects for equality. It is overridden to compare the contents of objects rather than their references.    public class Point {        private int x, y;        // C

Dynamic method dispatch

Dynamic method dispatch is a mechanism in Java where the method to be executed is determined at runtime rather than at compile time. It is also known as runtime polymorphism or late binding. In Java, dynamic method dispatch is achieved through method overriding, where a subclass provides a specific implementation of a method that is already present in its superclass. When a method is invoked on an object, the JVM determines which version of the method to execute based on the actual type of the object at runtime. Here's how dynamic method dispatch works: 1. Method Override: Subclasses can override methods defined in their superclass to provide specialized implementations. The subclass method must have the same signature (name and parameters) as the superclass method. 2. Runtime Binding: When a method is called on an object, the JVM determines the appropriate method implementation to execute based on the actual type of the object at runtime. 3. Polymorphic Behavior: Dynamic method

Interface Inheritance

In Java, interfaces can extend other interfaces, enabling interface inheritance. This allows one interface to inherit the methods and constants of another interface. The child interface inherits all the abstract methods, default methods, and static methods of the parent interface. Syntax: interface ParentInterface {     // Methods and constants } interface ChildInterface extends ParentInterface {     // Additional methods and constants } Example: interface Animal {     void eat(); } interface Dog extends Animal {     void bark(); } class Labrador implements Dog {     public void eat() {         System.out.println("Labrador is eating");     }     public void bark() {         System.out.println("Labrador is barking");     } } public class Main {     public static void main(String[] args) {         Labrador labrador = new Labrador();         labrador.eat();         labrador.bark();     } } In this example: - The `Animal` interface defines the `eat()` method. - The `Dog