Exception Handling and Custom Exceptions in Java

Objectives

1. Understand Exceptions in Java.
2. Implement try/catch/finally to handle Exceptions in Java.
3. Understand and implement custom exceptions in Java.

Problem Statement 1: Exception Handling

Task

1. Comment the displayProfile(String department) method in both the Payroll Interface and its implementation in the PayrollImpl class.
2. In Main.java, invoke displayProfile(Employee employee) by passing null as the parameter.
3. Handle the NullPointerException using a try/catch block.
4. Handle all possible exceptions in all methods of the PayrollImpl class.

Problem Statement 2: Custom Exceptions

Task

1. Create a new package com.trainingmug.employee.exception.
2. Under this package, create a new Exception class named InvalidBankAccountException.
3. Override the constructor public InvalidBankAccountException(String message) with a message.
4. In Employee.java:
   • Add the bankAccountNo (String) property.
   • Update the argument constructor to include the bankAccountNo property.
   • Generate getter and setter methods for this property.
   • Print the bankAccountNo in the displayProfile() method.
5. In Developer.java and Designer.java:
   • Add bankAccountNo in the constructor and pass it to the superclass constructor.
   • Print the bankAccountNo by invoking getBankAccountNo() in the displayProfile() method.
6. In Main.java, pass the bankAccountNo values for all Employee, Developer, and Designer objects.
7. In Payroll.java, create the following method:

   boolean processSalary(Employee employee) throws InvalidBankAccountException;

8. In PayrollImpl.java, implement the above method with the following rules:
   • If the bankAccountNo of the Employee is null or not 11 characters in length, throw InvalidBankAccountException with the appropriate message.
   • If the bankAccountNo is valid, display a message "Net Salary : $XXXX is successfully processed to XXXXX" and return true.
9. In Main.java, invoke the processSalary() method by passing existing Developer and Designer objects.
10. Handle the InvalidBankAccountException using a try/catch block and display the exception message in the catch block.
11. Create a Developer object with bankAccountNo as null and invoke the processSalary() method.
12. Observe the output:

"Hey XXXXXX, Invalid Bank Account, Please provide the proper Bank Account Number to process your salary."

13. Create another Developer object with bankAccountNo as 7 digits and invoke the processSalary() method.
14. Observe the output:

"Hey XXXXXX, Invalid Bank Account, Please provide the proper Bank Account Number to process your salary."

---

This README provides a high-level overview of the tasks and requirements for exception handling and custom exceptions in the Java application.