This is my code
Book.java :
public class Book {
private String id;
private String name;
private int quantity;
private String publisher;
private double price;
private double amount;
public Book(String id, String name, int quantity, String publisher, double price) {
super();
this.id = id;
this.name = name;
this.quantity = quantity;
this.publisher = publisher;
this.price = price;
}
public Book() {
this.id="";
this.name="";
this.publisher="";
// TODO Auto-generated constructor stub
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getQuantity() {
return quantity;
}
public void setQuantity(int quantity) {
this.quantity = quantity;
}
public String getPublisher() {
return publisher;
}
public void setPublisher(String publisher) {
this.publisher = publisher;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public double getAmount() {
return price*quantity;
}
public void setAmount(double amount) {
this.amount = amount;
}
}
TextBook.java :
public class TextBook extends Book {
private boolean status;
public TextBook(String id, String name, int quantity, String publisher, double price, boolean status) {
super(id, name, quantity, publisher, price);
this.status = status;
}
public boolean isStatus() {
return status;
}
public void setStatus(boolean status) {
this.status = status;
}
@Override
public double getAmount() {
// TODO Auto-generated method stub
if (status)
{
return super.getAmount();
} else {
return super.getAmount() * 0.5;
}
}
@Override
public String toString() {
return "TextBook [status=" + status + ", getId()=" + getId() + ", getName()=" + getName() + ", getQuantity()="
+ getQuantity() + ", getPublisher()=" + getPublisher() + ", getPrice()=" + getPrice() + ", getAmount()="
+ getAmount() + "]";
}
}
ReferenceBook.java:
class ReferenceBook extends Book
{
private double tax;
public ReferenceBook(String id, String name, int quantity, String publisher, double price) {
// TODO Auto-generated constructor stub
}
public ReferenceBook(String id, String name, int quantity, String publisher, double price,
double tax) {
super(id, name, quantity, publisher, price);
this.tax=tax;
}
@Override
public double getAmount() {
// TODO Auto-generated method stub
return super.getAmount() + tax;
}
@Override
public String toString() {
return "ReferenceBook [tax=" + tax + ", getId()=" + getId() + ", getName()=" + getName() + ", getQuantity()="
+ getQuantity() + ", getPublisher()=" + getPublisher() + ", getPrice()=" + getPrice()+ ", getAmount()=" + getAmount() + "]";
}
}
BookManagement.java:
import java.util.ArrayList;
import java.util.Scanner;
public class BookManagement {
public Book[] readData(Scanner sc) {
int n = sc.nextInt();
Book[] books = new Book[n];
for (int i=0; i < n; i++)
{
int a = Integer.parseInt(sc.nextLine());
String id = sc.nextLine();
String name = sc.nextLine();
int quantity = Integer.parseInt(sc.nextLine());
String publisher = sc.nextLine();
double price = Double.parseDouble(sc.nextLine());
if (a==1) {
boolean status = Boolean.parseBoolean(sc.nextLine());
books[i] = new TextBook(id, name, quantity, publisher, price, status);
}
if (a==0) {
double tax = Double.parseDouble(sc.nextLine());
books[i] = new ReferenceBook(id, name, quantity, publisher, price, tax);
}
}
return books;
}
public void printBooks(Book[] books) {
for (Book book : books)
{
System.out.println(book.toString());
}
}
public ArrayList<Book> findBooks(Book[] books, String publisher) {
ArrayList<Book> results = new ArrayList<Book>();
for (Book book : books)
{
if (book.getPublisher().equals(publisher))
{
results.add(book);
}
}
return results;
}
public double computeAverage(Book[] books, String typeOfBooks) {
double sum = 0;
int count = 0;
for (Book book : books)
{
if (book.getClass().getName().equals(typeOfBooks))
{
sum += book.getAmount();
count++;
}
}
return sum/count;
}
public void sortByPrice(Book[] books) {
for (int i=0; i<books.length-1; i++)
{
for (int j=i+1; j<books.length; j++)
{
if (books[i].getPrice() > books[j].getPrice())
{
Book temp = new Book();
temp = books[i];
books[i] =books[j];
books[j] = temp;
}
}
}
}
public static void main(String[] args) {
BookManagement bookManagement = new BookManagement();
Scanner input = new Scanner(System.in);
int c = Integer.parseInt(input.nextLine());
if (c==0)
{
Book[] books = bookManagement.readData(input);
bookManagement.printBooks(books);
}
if (c==1)
{
Book[] books = bookManagement.readData(input);
ArrayList<Book> bookResults = bookManagement.findBooks(books, "Nhà xuất bản giáo dục");
Book[] books1 = bookResults.toArray(new Book[bookResults.size()]);
bookManagement.printBooks(books1);
}
if (c==2)
{
Book[] books = bookManagement.readData(input);
System.out.println(bookManagement.computeAverage(books, "TextBook"));
}
if (c==3)
{
Book[] books = bookManagement.readData(input);
bookManagement.sortByPrice(books);
bookManagement.printBooks(books);
}
}
}
This is my input:
3
3
1
001
Dstt
3
NXBGD
10000
true
0
002
BTGT
4
NXBDHQG
20000
5000
1
003
GT
3
NXBGD
12000
false
And IntelliJ show:
Exception in thread "main" java.lang.NumberFormatException: For input string: "" at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:67) at java.base/java.lang.Integer.parseInt(Integer.java:670) at java.base/java.lang.Integer.parseInt(Integer.java:778) at labweek_10/Book.BookManagement.readData(BookManagement.java:22) at labweek_10/Book.BookManagement.main(BookManagement.java:112)
