INTRODUCTION:

The given Java program generates a random password of a specified length and constructs an email address by combining the provided user ID with the generated password. It uses predefined character sets for numbers, letters (both uppercase and lowercase), and symbols to create a diverse pool of characters for the password. The program prompts the user to enter an email ID and the desired password length, validates the input, generates the password, and constructs the email address. Finally, it displays the generated password and email address on the console.

TOPICS COVERD USED IN JAVA:

1. NUMBERS, CHARACTERS, and SYMBOLS: These are three constants declared as strings, representing the character sets to be used for generating the password. NUMBERS contains digits from 0 to 9, CHARACTERS contains both uppercase and lowercase letters, and SYMBOLS contains a set of special symbols.

2. generatePassword method: This method takes an integer length as a parameter and returns a randomly generated password of the specified length. It concatenates the CHARACTERS, NUMBERS, and SYMBOLS strings into the characters string. It then uses a SecureRandom object to generate random indices within the bounds of the characters string and appends the corresponding characters to a StringBuilder object. Finally, it returns the generated password as a string.

3. generateEmail method: This method takes two strings, user and password, as parameters and constructs an email address by appending the user string with the domain string (which is hardcoded as "@gmail.com"). The resulting email address is returned as a string.

4. main method: This is the entry point of the program. It prompts the user to enter an email ID and the desired length for the password using a Scanner object. It validates the user input and checks for empty input or negative password length. If the input is valid, it generates a random password using the generatePassword method and constructs an email address using the generateEmail method. Finally, it prints the generated password and email address to the console.

The code demonstrates concepts such as random number generation, string manipulation, user input validation, and basic console I/O operations in Java.

PACKAGES: import java.security.SecureRandom; import java.util.Scanner;