Thread: Delete method not deleting hard coded books

deleted

Do you have some print outs that show the problem? Please post them and add some comments where the problem is.

Note: The code for ILibrary is missing

Also posted here: https://coderanch.com/t/741159/java/...ing-hard-coded

deleted

The code with my debug statements:

/* https://www.javaprogrammingforums.com/whats-wrong-my-code/43659-delete-method-not-deleting-hard-coded-books.html#post171300
 
Note: delete works / code adds three books every time
*/
 
import java.util.Random;
import java.util.*;
import java.util.ArrayList;
import java.util.Objects;
import java.util.Random;
import java.util.Scanner;
 
 
 
public class MainLibrary1 {
 
    Library lib = new Library();
    public Scanner scan = new Scanner("4\n3\nNeverwhere\n4\n0\n"); //System.in);
 
 
    public static void main(String[] args) {
 
        MainLibrary1 main = new MainLibrary1();
        main.startPoint();
    }
 
    public void startPoint(){
        welcomeMessage();
        menuHeader();
        getUserInput();
    }
 
    private void welcomeMessage(){
        System.out.println("********************");
        System.out.println("*       Cork       *");
        System.out.println("*      Library     *");
        System.out.println("********************");
    }
 
    private void menuHeader(){
        System.out.println("********************");
        System.out.println("*       Menu       *");
        System.out.println("*     Options      *");
        System.out.println("********************");
    }
 
    private void menuOptions(){
        System.out.println("***********************");
        System.out.println("*1.) Add Book         *");
        System.out.println("*2.) Search for Book  *");
        System.out.println("*3.) Delete Book      *");
        System.out.println("*4.) Display all Books*");
        System.out.println("*0.) Exit Program     *");
        System.out.println("***********************");
    }
 
    private void getUserInput(){
        int choice;
        menuOptions();
        do{
            System.out.println(">");
            while(!scan.hasNext()){                         //???? nextInt
                scan.next();
                System.out.println("INTEGERS ONLY PLEASE");
            }
            choice = scan.nextInt();
            scan.nextLine();
            menuSelection(choice);
        }while(choice!= 0);
    }
 
    private void menuSelection(int choice){
        switch(choice){
            case 1: enterBookInfo();
            break;
 
            case 2:
            lib.bookInStock();
            inputSearch();
            break;
 
            case 3: inputBookToDelete();
            break;
 
            case 4:
            lib.bookInStock();       //???? keeps adding 3 books
            lib.printListOfBook();
            break;
 
            case 0:
//            lib.exit();            //<<<<<<<< error: cannot find symbol  method exit()
              System.exit(0); //<<<<<< ADDED
            break;
 
            default:
                break;
        }
    }
 
    private void enterBookInfo(){
        while(lib.keepGoing){
 
            System.out.println("Please enter name of book: ");
            String bookName = scan.nextLine();
 
            if (bookName.equalsIgnoreCase("end"))
            {
                break;
            }
 
            System.out.println("Please enter author: ");
            String authorName = scan.nextLine();
 
            System.out.println("Please enter ISBN Number: ");
            String isbnNumber = scan.nextLine();
 
            System.out.println("Please enter number of books in stock: ");
            int numberOfCopiesInStock = scan.nextInt();
            scan.nextLine();
 
            Book book = new Book(bookName, authorName, numberOfCopiesInStock, isbnNumber);
            lib.bookList.add(book);
        }
    }
 
    private void inputSearch(){
        System.out.println("\n**********Search for Book**********");
        System.out.println("Please enter BookName: ");
        lib.search = scan.nextLine();
        makeTheComputerSleep();
        lib.searchForBooks();
    }
 
    private void inputBookToDelete(){
 
        System.out.println("\n**********Delete Employee**********");
        System.out.println("Please enter book name: ");
        lib.deleteBookName = scan.nextLine();
        lib.deleteBooks();
    }
 
    public void makeTheComputerSleep(){
        int number = lib.random.nextInt(10)+1;
        System.out.println("Check system......please wait....");
        try{
            Thread.sleep(number * 1000);
        }catch(InterruptedException e){
            e.printStackTrace();
        }
    }
//>>>>>>>>>rb
 
static interface ILibrary {
 
    int MAX_NUMBER_OF_COPIES = 3;
    int MIN_NUMBER_OF_COPIES = 0;
    int ISBN_MAX_NUMBER_OF_DIGITS = 10;
}
 
 
static class Book implements ILibrary {
 
    private String bookName;
    private String authorName;
    private int numberOfCopiesInStock;
    private String Isbn;
 
    public Book(String bookName,String authorName,int numberOfCopiesInStock,String Isbn){
        this.setBookName(bookName);
        this.setAuthorName(authorName);
        this.setNumberOfCopiesInStock(numberOfCopiesInStock);
        this.setIsbn(Isbn);
    }
 
    public void setBookName(String bookName)throws IllegalArgumentException{
        if(bookName.isEmpty()){
            throw new IllegalArgumentException("FIELD CANNOT BE EMPTY!");
        }else{
            this.bookName = bookName;
        }
    }
 
    public void setAuthorName(String authorName)throws IllegalArgumentException{
        if(authorName.isEmpty()){
            throw new IllegalArgumentException("FIELD CANNOT BE EMPTY");
        }else{
            this.authorName = authorName;
        }
    }
 
    public void setNumberOfCopiesInStock(int numberOfCopiesInStock)throws IllegalArgumentException{
        if(numberOfCopiesInStock < MIN_NUMBER_OF_COPIES || numberOfCopiesInStock > MAX_NUMBER_OF_COPIES){
            throw new IllegalArgumentException("INVALID NUMBER OF COPIES ENTERED INTO STOCK!");
        }else{
            this.numberOfCopiesInStock = numberOfCopiesInStock;
        }
    }
 
    public void setIsbn(String Isbn)throws IllegalArgumentException{
        if(Isbn.length() < ISBN_MAX_NUMBER_OF_DIGITS || Isbn.length() > ISBN_MAX_NUMBER_OF_DIGITS){
            throw new IllegalArgumentException("ISBN LENGTH ENTERED IS INVALID,TRY AGAIN");
        }else{
            this.Isbn = Isbn;
        }
    }
 
    public String getBookName(){
        return this.bookName;
    }
 
    public String getAuthorName(){
        return this.authorName;
    }
 
    public int getNumberOfCopiesInStock(){
        return this.numberOfCopiesInStock;
    }
 
    public String getIsbn(){
        return this.Isbn;
    }
 
    public String toString(){
        return("BookName: " + getBookName()
                +"\n"
                +"AuthorName: " + getAuthorName()
                +"\n"
                +"Number of Copies: " + getNumberOfCopiesInStock()
                +"\n"
                +"ISBN: " + getIsbn());
    }
 
 
 
 
 
}
 
 
static class Library {
 
    public String search;
    public String deleteBookName;
    public boolean keepGoing = true;
    public Random random = new Random();
    public ArrayList<Book> bookList = new ArrayList<Book>();
 
    public void bookInStock(){
        Book book1 = new Book("Neverwhere","Neil Gaimen",2,"A100023454");
        Book book2 = new Book("American Gods","Neil Gaimen",1,"A100023454");
        Book book3 = new Book("I.T","Stephen King",0,"A123432454");
        bookList.add(book1);
        bookList.add(book2);
        bookList.add(book3);
        System.out.println(">>>>>>>> END adding 3 books <<<<<<<<<");  //  Called more than one time!!!
    }
 
    public Boolean searchForBooks(){
        for(Book b : bookList){
 
            if(b.getBookName().equalsIgnoreCase(search)){
                System.out.println(b);
                return true;
            }
        }
        System.out.println("BOOK DOESN'T EXIST! ");
        return false;
    }
 
    public void printListOfBook(){
        for(Book b : bookList){
            System.out.println(b.toString());
            System.out.println();
        }
    }
 
    public void deleteBooks(){
        for(Book b : bookList){
            System.out.println("deleteBookName="+deleteBookName + "< vs >" + b.getBookName()+"<");
            if(deleteBookName.equalsIgnoreCase(b.getBookName())){
                boolean results = bookList.remove(b);
                System.out.println("results="+results + " for b=" + b); //results=true for b=BookName: Neverwhere
                System.out.println("bL="+bookList + "\n<<<< end");
                break;
            }
        }
    }
   }
 
} // end class

How are you trying to debug the code to find the problem?
I suggest adding some print statements that show the values of variables as they are changed and used
and to show the values and results in the delete method.
The print out will help you find the problem.

Note: Several of the methods are poorly named. Method names should be verbs describing what the method is supposed to do.