IllegalArgumentException: Thrown to indicate that a method has been passed an illegal or inappropriate argument.
Example:

public static void checkAge(int age) {
 if (age < 18) {
 throw new IllegalArgumentException("Age must be at least 18");
 }
}
try {
 checkAge(16);
} catch (IllegalArgumentException e) {
 System.out.println("Caught IllegalArgumentException: " + e.getMessage());
}