throws: Exception Propagation

In this problem, you will create a program that propagates exceptions from a method to its caller using the throws keyword and implements a file name validation system.

Learning Objective: Learn to propagate exceptions to caller using throws keyword

Overview

throws keyword declares that a method may throw specific exceptions. It delegates exception handling responsibility to the caller.

Specifications

Implement a file name validation system:

1. FileValidator class:

   • static void validateFileName(String fileName) throws IllegalArgumentException
     • If fileName is null or empty, throw IllegalArgumentException
     • Message: "Invalid file name"
     • If valid: output "Valid file name: [fileName]"

2. Main class:

   • Use try-catch to execute:
     • Validate "document.txt" (success)
     • Validate "" (empty string — throws exception)
     • catch: output "Error: [exception message]"
     • Validate "report.pdf" (success)

How Tests Work

This problem tests the validateFileName method directly, verifying both normal cases (no exception) and error cases (IllegalArgumentException thrown).