Person Class

$/**$

$*$ Person Class

$*$ Class contains: First name, Last name, and age

$*/$

public class Person $\{$

$//$Attributes$/$fields

private String firstName;

private String lastName;

private int personAge;

$/**************************************$

$*$ Constructors

$**************************************/$

$//$Constructors $($Default$)$

public Person$()$

$\{$

firstName $=$ "None";

lastName $=$ "None";

personAge $=0$;

$\}$

$//$Constructors $($Populates data with arguments$)$

public Person$($String pFirst, String pLast, int pAge$)$

$\{$

setFirstName$($pFirst$)$;

setLastName$($pLast$)$;

setPersonAge$($pAge$)$;

$\}$

$/**************************************$

$*$ Getters$/$Setters

$**************************************/$

public String getFirstName$()\{$

return firstName;

$\}$

public void setFirstName$($String firstName$)\{$

this.firstName $=$ firstName;

$\}$

public String getLastName$()\{$

return lastName;

$\}$

public void setLastName$($String lastName$)\{$

this.lastName $=$ lastName;

$\}$

public int getPersonAge$()\{$

return personAge;

$\}$

public void setPersonAge$($int personAge$)\{$

this.personAge $=$ personAge;

$\}$

$/**************************************$

$*$ Methods

$**************************************/$

public String PrintData$()$

$\{$

String myReturn $=""$;

myReturn $+=$ "Name: $"+$ getFirstName$()+""+$ getLastName$()$;

myReturn $+="$ Age: $"+$ getPersonAge$()$;

return myReturn;

$\}$

$\}//$ END Person Class

The provided Java class, Person, models a person and their attributes such as first name, last name, and age.

Attributes$/$fields: The class has three private instance variables or attributes $-$ firstName, lastName, and personAge. They are private to ensure data encapsulation, which means they can be accessed or modified only through methods within the Person class itself.

Constructors: The class provides two constructors:

Default constructor $($public Person$())$: This constructor initializes the firstName and lastName fields to "None" and the personAge to $0.$

Parameterized constructor $($public Person$($String pFirst, String pLast, int pAge$))$: This constructor uses parameters to initialize the firstName, lastName, and personAge fields. It uses the provided setter methods to set the values.

Getters$/$Setters: These are methods that allow outside code to safely access $($get$)$ or modify $($set$)$ the private instance variables. This is a common practice in object$-$oriented programming to enforce encapsulation. In this class, there are getter and setter methods for each of the three private attributes.

Methods:

PrintData$()$: This method returns a String which includes the person's first name, last name, and age. It uses the getter methods to access the private instance variables.

In summary, this class represents a simple model of a person. It demonstrates several key principles of object$-$oriented programming, such as encapsulation $($using private fields and public getter$/$setter methods$),$ constructors to initialize objects, and methods to represent behaviors or actions associated with the object $($in this case, printing the person's data$).$

Driver Program

$/*$

$*$ Code writes a file and reads the data into an ArrayList of the Person object

$*/$

import java.util.ArrayList;

import java.util.Scanner;

import java.io$.$File; $//$ Import for File Object

import java.io$.$IOException; $//$ Import for IO Exceptions

import java.io$.$FileWriter; $//$ Import the FileWriter class

import java.io$.$FileNotFoundException; $//$ Import this class to handle errors

public class LabDriver $\{$

public static void main$($String$[]$ args$)\{$

$//****************************************************************$

$//$Variables we will use in the program

$//****************************************************************$

ArrayList Students $=$ new ArrayList$()$;

String firstName;

String lastName;

int age;

int index $=0$; $//$index for the ArrayList

$//****************************************************************$

$//$Lets create our Data File

$//$here we will use a try$/$catch in the event something goes wrong

$//****************************************************************$

try $\{$

$//$Create an instance of the File Writer and give it the filename

FileWriter myWriter $=$ new FileWriter$("$Person$.$txt$")$;

$//$Write our data to the file

myWriter.write$("$Kevin Roark $29$

$"$

$+$ "Sam Read $21$

$"$

$+$ "Sally Smith $34$

$"$

$+$ "Bart Simpson $14")$;

$//$close the file we opened $-$ MUST BE DONE

myWriter.close$()$;

$//$Message that all was done

System.out.println$("$Successfully wrote to the file."$)$;

$\}$

catch $($IOException e$)$

$\{$

$//$An issue happened $-$ Message user

System.out.println$("$An error occurred."$)$;

e$.$printStackTrace$()$;

$\}$

$//****************************************************************$

$//$Now lets read the file into our ArrayList of object Person

$//********************************************$