Java Programming By Mohit

Java offers a comprehensive set of cryptographic functionalities through its `java.security` package. This package provides various classes and interfaces for encryption, decryption, key generation, digital signatures, and more. Here are some key classes and concepts within Java's Cryptography API: 1. **Message Digests (Hashing):** Classes like `MessageDigest` help generate hash values for data using algorithms like MD5, SHA-1, SHA-256, etc. 2. **Encryption/Decryption:** The `Cipher` class allows encryption and decryption using various algorithms like AES, DES, RSA, etc. 3. **Key Management:** Java provides classes such as `KeyGenerator` for generating symmetric keys, `KeyPairGenerator` for key pairs (for asymmetric encryption), and `KeyStore` for managing keys and certificates. 4. **Digital Signatures:** The `Signature` class helps create and verify digital signatures. Here's a simple example demonstrating encryption and decryption using Java's Cryptography API: ```java im...

 In Java, a `String` is an object that represents a sequence of characters. It belongs to the `java.lang` package, and it's widely used for handling textual data. Here are some essential methods associated with the `String` class: 1. **Creating Strings:**    - `String myString = "Hello, World!";` - Creates a string literal.    - `String anotherString = new String("Java");` - Creates a string using the `new` keyword. 2. **Length:**    - `int length = myString.length();` - Returns the length of the string. 3. **Concatenation:**    - `String combined = myString + " " + anotherString;` - Concatenates strings. 4. **Substring:**    - `String sub = myString.substring(7);` - Extracts a substring from the original string. 5. **Concatenation with Other Data Types:**    - `int number = 42;`    - `String result = "The answer is " + number;` - You can concatenate strings with other data types. 6. **Comparison:**    ...

I can provide you with an example code snippet in Java for email validation using a `JTextField`. Here's an example: import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.regex.*; public class EmailValidationExample {     private JFrame frame;     private JTextField emailTextField;     private JButton validateButton;     public EmailValidationExample() {         frame = new JFrame("Email Validation");         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);                  emailTextField = new JTextField(20);         validateButton = new JButton("Validate");         validateButton.addActionListener(new ActionListener() {             public void actionPerformed(ActionEvent e) {                 String email = emailTextField...

  In C#, event handling is the process of responding to an occurrence of a particular event. Events can be raised by user actions, such as clicking a button or pressing a key, or they can be raised by the system or other components of an application. Here are the steps involved in handling events in C#: Define the delegate: A delegate is a type that represents a method that can be called when an event occurs. In C#, delegates are used to define event handlers. You can define your own delegate or use one of the pre-defined delegates provided by the .NET framework. Define the event: An event is a mechanism for raising a notification that something has happened. In C#, you can define your own events by creating an instance of the delegate that will handle the event. Subscribe to the event: To handle an event, you must subscribe to it. This is done by creating an instance of the delegate that will handle the event, and then adding this instance to the event's invocation list. Define th...

import java.awt.* ; import java.awt.event.* ;   //Basic Addition Program in Java AWT class MyApp extends Frame implements ActionListener {   Label l1, l2, l3 ; TextField txt1 ; TextField txt2 ; Button b ;   public MyApp ( ) { super ( "Tutor Joes" ) ; setSize ( 1000 , 600 ) ; // w,h setLayout ( null ) ; setVisible ( true ) ;   l1 = new Label ( "Enter The Value 1 : " ) ; l1. setBounds ( 10 , 50 , 100 , 30 ) ;   txt1 = new TextField ( ) ; txt1. setBounds ( 150 , 50 , 250 , 30 ) ;   l2 = new Label ( "Enter The Value 2 : " ) ; l2. setBounds ( 10 , 100 , 100 , 30 ) ;   txt2 = new TextField ( ) ; txt2. setBounds ( 150 , 100 , 250 , 30 ) ;   b = new Button ( "Click Me" ) ; b. setBounds ( 150 , 150 , 100 , 30 ) ; b. addActionListener ( this ) ;   l3 = new Label ( "--" ) ; l3. setBounds ( 10 , 200 , 300 , 30 ) ;   add ( l1 ) ; add ( txt1 ) ; ad...

Java  programming is one of the most popular programming languages in the world. It is an object-oriented programming language that is widely used for developing web applications, mobile applications, and desktop applications. Java was first introduced in 1995 by Sun Microsystems and has since become one of the most widely used programming languages in the world. As an assistant professor in Vivek College Bijnor , I have had the opportunity to teach Java programming to students from various backgrounds. I would like to extend a special thank you to the Management of Vivek College for supporting me in writing this blog. Their support has been invaluable, and I am grateful for the opportunity to share my knowledge and experiences with a wider audience. In this blog, I will discuss some of the basics of Java programming that are important for beginners to understand. Variables and Data Types Variables are used to store values in Java programming. A variable is a memory locati...