Here is a Java program that meets your requirements: ```java import java.util.Scanner; import java.util.regex.Pattern; class InvalidNameException extends Exception { InvalidNameException(String s) { super(s); } } class InvalidRegNumberException extends Exception { InvalidRegNumberException(String s) { super(s); } } class InvalidAgeException extends Exception { InvalidAgeException(String s) { super(s); } } class InvalidPhoneNumberException extends Exception { InvalidPhoneNumberException(String s) { super(s); } } class Student { String name; String regNumber; int age; String phoneNumber; Student(String name, String regNumber, int age, String phoneNumber) throws InvalidNameException, InvalidRegNumberException, InvalidAgeException, InvalidPhoneNumberException { if (!name.matches("[a-zA-Z]+")) { throw new InvalidNameException("Name should contain only alphabets"); } if (!Pattern.matches("\d{2}[a-zA-Z]{3}\d{4}", regNumber)) { throw new InvalidRegNumberException("Invalid Registration Number"); } if (age = 21) { throw new InvalidAgeException("Age should be greater than 18 and less than 21"); } if (!Pattern.matches("\d{10}", phoneNumber)) { throw new InvalidPhoneNumberException("Phone Number should be 10 digits"); } this.name = name; this.regNumber = regNumber; this.age = age; this.phoneNumber = phoneNumber; } String getEmail() { return name.toLowerCase() + "2021@vitstudent.ac.in"; } String getPassword() { return name.toUpperCase().substring(0, 4) + regNumber.substring(regNumber.length() - 4) + "@"; } } public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.println("Enter Name:"); String name = sc.nextLine(); System.out.println("Enter Reg. Number:"); String regNumber = sc.nextLine(); System.out.println("Enter Age:"); int age = sc.nextInt(); System.out.println("Enter Phone Number:"); String phoneNumber = sc.next(); try { Student student = new Student(name, regNumber, age, phoneNumber); System.out.println("Email: " + student.getEmail()); System.out.println("Password: " + student.getPassword()); } catch (Exception e) { System.out.println(e.getMessage()); } } } ``` This program creates a `Student` class with the required fields and checks for valid input in the constructor. If the input is invalid, it throws an exception. The `getEmail` and `getPassword` methods generate the email and password according to your specifications. The `main` method prompts the user for input and creates a `Student` object. If the input is invalid, it prints the error message.

Question

Here is a Java program that meets your requirements:

```java
import java.util.Scanner;
import java.util.regex.Pattern;

class InvalidNameException extends Exception {
    InvalidNameException(String s) {
        super(s);
    }
}

class InvalidRegNumberException extends Exception {
    InvalidRegNumberException(String s) {
        super(s);
    }
}

class InvalidAgeException extends Exception {
    InvalidAgeException(String s) {
        super(s);
    }
}

class InvalidPhoneNumberException extends Exception {
    InvalidPhoneNumberException(String s) {
        super(s);
    }
}

class Student {
    String name;
    String regNumber;
    int age;
    String phoneNumber;

Student(String name, String regNumber, int age, String phoneNumber) throws InvalidNameException, InvalidRegNumberException, InvalidAgeException, InvalidPhoneNumberException {
        if (!name.matches("[a-zA-Z]+")) {
            throw new InvalidNameException("Name should contain only alphabets");
        }
        if (!Pattern.matches("\d{2}[a-zA-Z]{3}\d{4}", regNumber)) {
            throw new InvalidRegNumberException("Invalid Registration Number");
        }
        if (age <= 18 || age >= 21) {
            throw new InvalidAgeException("Age should be greater than 18 and less than 21");
        }
        if (!Pattern.matches("\d{10}", phoneNumber)) {
            throw new InvalidPhoneNumberException("Phone Number should be 10 digits");
        }
        this.name = name;
        this.regNumber = regNumber;
        this.age = age;
        this.phoneNumber = phoneNumber;
    }

String getEmail() {
        return name.toLowerCase() + "2021@vitstudent.ac.in";
    }

String getPassword() {
        return name.toUpperCase().substring(0, 4) + regNumber.substring(regNumber.length() - 4) + "@";
    }
}

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("Enter Name:");
        String name = sc.nextLine();
        System.out.println("Enter Reg. Number:");
        String regNumber = sc.nextLine();
        System.out.println("Enter Age:");
        int age = sc.nextInt();
        System.out.println("Enter Phone Number:");
        String phoneNumber = sc.next();

try {
            Student student = new Student(name, regNumber, age, phoneNumber);
            System.out.println("Email: " + student.getEmail());
            System.out.println("Password: " + student.getPassword());
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}
```

This program creates a `Student` class with the required fields and checks for valid input in the constructor. If the input is invalid, it throws an exception. The `getEmail` and `getPassword` methods generate the email and password according to your specifications. The `main` method prompts the user for input and creates a `Student` object. If the input is invalid, it prints the error message.

Knowee AI · Accepted Answer