public class Employee2 {
    private final int employeeID;
    private final String[] names;
    private final double hourlyRate;
    
    // Note: This code assumes InvalidEmployeeException
    // is in the same package as this source code.
    public Employee2(final int id, final double hourlyRate,
        final String... names) throws InvalidEmployeeException {

        // set employeeID
        if (id <= 0) throw new InvalidEmployeeException("ID less than 1");
        this.employeeID = id;
        // set hourlyRate
        if (hourlyRate < 0.0) throw new InvalidEmployeeException("Employee rate less than 0");
        this.hourlyRate = hourlyRate;
        // set names (last name is required at a minimum)
        if (names == null || names.length < 1) throw new InvalidEmployeeException("Last name is missing");
        this.names = (String[])names.clone();
    }
    public int getID() { return employeeID; }
    public double getHourlyRate() { return hourlyRate; }
    public String getFirstName(final int pos) {
        // last position in array reserved for last name
        if (pos >= names.length-1) return null;
        else return names[pos];
    }
    public String getLastName() { return names[names.length-1]; }
    public int getNumberOfFirstNames() { return names.length-1; }
    public String toString() {
        String result = "Employee: #" + employeeID + ", Name: ";
        for (int i=0; i<names.length-1; i++) result = result + names[i] + " ";
        result += names[names.length-1] + " (Rate: "
            + String.format("$%.2f", hourlyRate) + ")";
        return result;
    }
}