Has to be in Java (Bluejay) 1) Polish the class that you proposed as your proble

Question

Has to be in Java (Bluejay)

1) Polish the class that you proposed as your problem statement.

(1.5 points) at least 3 instance variables of different types (e.g., String, int, double, boolean, etc).

(1.5 points) a default constructor that is composed of a sequence of this.set() methods.

(1.5 points) a custom constructor that is composed of a sequence of this.set() methods.

(1.5 points) a get() method for each instance variable

(1.5 points) a set() method for each instance variable. Each set() method uses the this keyword.

(1.5 points) a toString() method

2) Write a Tester for your class that sets up a data set each of whose elements is of your class’ type. Your tester must meet the following requirements

(1 point) Instantiates an array of a certain size – e.g, 10 elements (like in the reference code)

(2 points) Takes user input to populate the array

(2 points) Uses a do-while loop and a switch statement (like we did in a previous lab) to ask the user what they want to do with the data

(6 points @ 1.5 points each) Has at least four options that will correctly handle the user’s selection when called.

Option 1: Search the array for objects that meet a search criterion. Display the objects if found.

Option 2: Replace an object at a given index with another object.

Option 3: Allow the user to select an element from the array and then modify the element (e.g., select a person from the array of persons and then sets the name of that person to a new value).

Option 4: Sort the array of objects according to a given criterion (e.g., sort the array of persons by height).

Option 5: Exit the program.

Explanation / Answer

Solution 1:

"Polish the class that you proposed as your problem statement."

Please provide the class to be improved ( or polish)

Solution 2:

Please find the implementation:

Assumptions: Since here in the problem statement 'Person' is held as example so a default implementation with some data members is used to complete the Tester class of Q2.

PersonSample.java [Person]

import java.util.Comparator;

public class PersonSample {

private String name;
private int age;
private double height;

//Parameterized Constructor
public PersonSample(String name, int age, double height) {
super();
this.name = name;
this.age = age;
this.height = height;
}
//Respective getter() and setter()

public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public double getHeight() {
return height;
}
public void setHeight(double height) {
this.height = height;
}

//hasCode() and equals() for comparing objects for eg: search
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((name == null) ? 0 : name.hashCode());
return result;
}

@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
PersonSample other = (PersonSample) obj;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
return true;
}

//Comparators for sorting on the given criterion
static Comparator<PersonSample> nameComparator = Comparator.comparing(PersonSample :: getName);
static Comparator<PersonSample> ageComparator = Comparator.comparing(PersonSample :: getAge);
static Comparator<PersonSample> heightComparator = Comparator.comparing(PersonSample :: getHeight);

@Override
public String toString() {
return "PersonSample [name=" + name + ", age=" + age + ", height=" + height + "]";
}

}

ArrayOptions.java

import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class ArrayOptions {

static PersonSample[] personArray = new PersonSample[10];

public static PersonSample takeUserInput(){
System.out.println("Enter details of person in the following sequence [Name, Age, Height]: ");
Scanner scanner = new Scanner(System.in);
String name = scanner.nextLine();
int age = scanner.nextInt();
double height = scanner.nextDouble();
return new PersonSample(name, age, height);
}

public static void choice(){
System.out.println("1.Search 2.Replace with given index 3.Modify 4.Sort with Name OR Age OR Height 5.Exit");
//ask input from user
System.out.println("Enter your choice: ");
Scanner inputScanner=new Scanner(System.in);
int inputChoice=inputScanner.nextInt();
int check=inputChoice;

//User will be asked for choice until chosen for Exit
while (inputChoice!=5){
System.out.println("1.Search 2.Replace with given index 3.Modify 4.Sort with Name OR Age OR Height 5.Exit");
int exitChoice=inputScanner.nextInt();
check=exitChoice;
}
switch (check){
case 1 :
System.out.println("Pleas enter name to search");
search(inputScanner.nextLine());
break;
case 2 :
System.out.println("Please enter the index");
int index = inputScanner.nextInt();
replace(index, takeUserInput());
break;
case 3 :
modify();
break;
case 4 :
System.out.println("Choose one criteria to sort among Name OR Age Height : ");
String choiceOfSortingCriteria = inputScanner.nextLine();
sort(choiceOfSortingCriteria);
break;
case 5 :
System.exit(0);
break;
}
}

//Method to search
public static void search(String name){
for(int i=0; i<personArray.length;i++){
int age=0;double height=0f;
if(personArray[i].equals(new PersonSample(name,age, height))){
System.out.println("Found : " + personArray[i].toString());
}else{
System.out.println("Not Found");
}
}
}

//Method to replace
public static void replace(int index, PersonSample personObject){
if(index > personArray.length){
System.out.println("Please enter valid index");
}
personArray[index] = personObject;
}

//Method to modify
public static void modify(){
System.out.println("Choose from the objects listed to modify:");
for(int i=0;i<personArray.length;i++){
System.out.println(personArray.toString());
}
System.out.println("Select index [1-10]:");
Scanner scanner = new Scanner(System.in);
int indexSelected = scanner.nextInt();
personArray[indexSelected] = takeUserInput();;
}

//Method to sort
public static void sort(String criterion){
List<PersonSample> buffList = Arrays.asList(personArray);
if(criterion.equalsIgnoreCase("name"))
Collections.sort(buffList, PersonSample.nameComparator);
else if(criterion.equalsIgnoreCase("age"))
Collections.sort(buffList, PersonSample.ageComparator);
else if(criterion.equalsIgnoreCase("height"))
Collections.sort(buffList, PersonSample.heightComparator);
System.out.println("Sorted list: ");
buffList.forEach(person -> System.out.println(person.toString()));
}
public static void main(String[] args) {
// TODO Auto-generated method stub

//Taking 10 user inputs
for(int i = 0; i< 10; i++){
personArray[i] = takeUserInput();
}

choice();
}

}

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