Question

Create a class called CarNode which has fields for the data (a Car) and next (CarNode) instance variables. Include a one-argument constructor which takes a Car as a parameter. (For hints, see the PowerPoint on "Static vs. Dynamic Structures”.)

public CarNode (Car c) { . . }

The instance variables should have protected access. There will not be any get and set methods for the two instance variables.

Create an abstract linked list class called CarList. This should be a linked list with head node as described in lecture. Modify it so that the data type in the nodes is Car. The no-argument constructor should create an empty list with first and last pointing to an empty head node, and length equal to zero. Include an append method in this class.

Create two more linked list classes that extend the abstract class CarList: One called UnsortedCarList and one called SortedCarList, each with appropriate no-argument constructors. Each of these classes should have a method called add(Car) that will add a new node to the list. In the case of the UnsortedCarList it will add it to the end of the list by calling the append method in the super class. In the case of the SortedCarList it will insert the node in the proper position to keep the list sorted.

Instantiate two linked lists, and for every car read from the file, add it to the unsorted and sorted lists using the add method. You will end up with the first list having the cars from the input file in the order they were read, and in the second list the cars will be in sorted order. Display the unsorted and sorted cars in the GUI just as in project 1.

Submitting the Project.

You should now have the following files to submit for this project:

Project2.java

Car.java

CarGUI.java

CarNode.java

CarList.java

UnsortedCarList.java

SortedCarList.java

Answer 1

Sample Input:

Sample Output:

Code to be Copied:

Project2.java

//import required packages
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;
import java.util.StringTokenizer;

//declare class Project2
public class Project2 {
   //main method
   public static void main(String[] args) throws FileNotFoundException {
       // TODO Auto-generated method stub
       //Read File
       Scanner readFile = new Scanner(new File("Cars.txt"));
       //Create Array
       List<Car> sortedCar = new ArrayList<>();
       List<Car> unSortedCar = new ArrayList<>();
       //Read and put it in array
       while(readFile.hasNextLine()) {
           StringTokenizer st = new StringTokenizer(readFile.nextLine(), ",");
           if(st.countTokens()!=4)
           {
               System.out.println(st.toString());
           }
           else
           {
               Car car = new Car(st.nextToken(), st.nextToken(),
                       Integer.parseInt(st.nextToken()),
                       Integer.parseInt(st.nextToken()));
               sortedCar.add(car);
               unSortedCar.add(car);
           }
       }
       //Sort using selection sort
       Collections.sort(sortedCar);
       //Call the method using the object carGui
       CarGui carGui = new CarGui(sortedCar, unSortedCar);
   }
}

Car.java

//declare class which implements
//comparable interface
public class Car implements Comparable<Car>
{
   String make;
   String model;
   int year;
   int mileage;
  
   //Default constructor
   public Car()   
   {
       this.make="";
       this.model="";
       this.year=0;
       this.mileage=0;
   }

   //getter and setter method for make
   public String getMake() {
       return make;
   }
   public void setMake(String make) {
       this.make = make;
   }
  
   //getter and setter method for model
   public String getModel() {
       return model;
   }
   public void setModel(String model) {
       this.model = model;
   }
  
   //getter and setter method for year
   public int getYear() {
       return year;
   }
   public void setYear(int year) {
       this.year = year;
   }
   //getter and setter method for mileage
   public int getMileage() {
       return mileage;
   }
   public void setMileage(int mileage)
   {
       this.mileage = mileage;
   }
  
   //paremetrized construtor
   public Car(String make, String model,
           int year, int mileage)
   {
       super();
       this.make = make;
       this.model = model;
       this.year = year;
       this.mileage = mileage;
   }
  
   //override methpd toString()
   @Override
   public String toString()
   {
       return "make=" + make + ", model=" + model
               + ", year=" + year + ", mileage=" + mileage ;
   }

   @Override
   public int compareTo(Car o)
   {
       // TODO Auto-generated method stub
       return this.make.compareTo(o.make);
   }
}

CarGui.java

//import required packages
import java.awt.GridLayout;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JTextArea;

//declare class CarGui
public class CarGui extends JFrame
{
   //constuctor to prepare GUI
   public CarGui(List<Car> sortedCar, List<Car> unSortedCar)
   {
       // TODO Auto-generated constructor stub
       prepareGUI(sortedCar, unSortedCar);
   }

   //implement method prepareGUI
   private void prepareGUI(List<Car> sortedCar, List<Car> unSortedCar)
   {
       // TODO Auto-generated method stub
       this.setSize(800, 400);
       //Text field to display
       JTextArea lblSorted = new JTextArea();
       JTextArea lblUnSorted = new JTextArea();

       StringBuffer sbSortedCar = new StringBuffer();
       StringBuffer sbUnSortedCar = new StringBuffer();
       //Add cars to text field
       for (int i = 0; i < sortedCar.size(); i++) {
           sbSortedCar.append(sortedCar.get(i).toString() + "\n");
           sbUnSortedCar.append(unSortedCar.get(i).toString() + "\n");
       }

       lblSorted.setText(sbSortedCar.toString());
       lblUnSorted.setText(sbUnSortedCar.toString());
       //DEfine layout
       GridLayout layout = new GridLayout(1, 2);
       layout.setHgap(10);
       layout.setVgap(10);
       this.setLayout(layout);
       this.add(lblUnSorted);
       this.add(lblSorted);
       this.setVisible(true);
       this.setTitle("Cars Sort List");
   }
}

CarNode.java

// CarNode.java
public class CarNode {
   //attributes
   protected Car car;
   protected CarNode next;

   //one arg constructor
   public CarNode(Car c)
   {
       this.car = c;
   }   
}

CarList.java

//create abstart CarList
public abstract class CarList
{
   //attributes
   protected CarNode head;
   protected CarNode last;
   protected int length;

   //default constructor
   public CarList()
   {
       head=null;
       last=null;
       length=0;
   }

   //method to add a box at the end
   public void append(Car car)
   {
       CarNode node=new CarNode(car);
       if(head==null){
           head=node;
           last=node;
       }else{
           last.next=node;
           last=node;
       }
       length++;
   }
  
   //override the method toString
   @Override
   public String toString() {
       /**
       * returns the list as a String
       */
       String data = "";
       CarNode node = head;
       while (node != null)
       {
           data += node.car.toString() + "\n";
           node = node.next;
       }
       return data;
   }
}

UnsortedCarList.java

//define the class UnsortedBoxList which extends the CarList
public class UnsortedCarList extends CarList {
   //define the Constructor
   public UnsortedCarList()
   {
       //call the variables
       super();
   }
   //implement the method add
   public void add(Car unsortedcar)
   {
       //just append values to the text area
       append(unsortedcar);
   }
}

SortedBoxList.java

//define the class which extends the abstract class
public class SortedBoxList extends CarList {
   //Constructor
   public SortedBoxList()
   {
       //call variables though super keyWord
       super();
   }
   //implement the method add()
   public void add(Car car)
   {
       //define the head for the previous and
       //current nodes in the liked list
       CarNode prev = head,curr = head.next;
       //define the nodes
       CarNode node = new CarNode(car);
       //Using while loop
       while(curr != null && car.toString().
           compareTo(curr.car.toString()) > 0)
       {
           //set previoud node as current node
           prev = curr;
           //set current node as next node
           curr = curr.next;
       }
       //set node to next is current node
       node.next = curr;
       //previous to next is node
       prev.next = node;

       //If node to next value is null
       if(node.next == null)
       {
           //set that is as last node
           last = node;
           //increment the node
           length++;
       }
   }
}

Text file to be Copied:

Cars.txt

Subaru,Forester,2018,12902
Toyota,Camry,2016,24536
Nissan,Maxima,2009,45648
Honda,Civic,2002,98304
Subaru,Legacy,2014,2034
Hyundai,Kona,2012,27890
Toyota,Rav4,2013,6547
Honda,Accord
Honda,CR-V,2010,13904
Nissan,Altima,2012,45376
Honda,Pilot,2013,54398
Nissan,Leaf,2018,2300
Acura,MDX,2017,3892