How to Iterate a arraylist of objects to find a specified object

Question

I am having trouble understanding and getting this function of my program to work. I am creating a library where I first input multiple objects into an array-list. The objects consist of title and format of the media. I need to be able to search through the objects in my array-list to find a specific object and mark that object as "checked out". I have been researching iterators and trying to understand how to make them find a specified title within an object but I am having trouble. I am getting MediaItem@3c4568f8 when I attempt to println(it.next()); so I know there is a problem with returning the correct format of information. Any help on how to search through the objects in my items array-list would be greatly appreciated.

import java.util.Iterator;
import java.util.Scanner;
import java.util.ArrayList;

public class Library {

    static ArrayList<MediaItem> items = new ArrayList<MediaItem>();
    static int menuOption;
    static Scanner scan = new Scanner(System.in);

    public static void main(String args[]) {
        String title, format, loanedTo, dateLoaned;
        boolean right = false;

        do {
            displayMenu();
            if (menuOption == 1) {
                System.out.println("Enter Title: ");
                title = scan.next();
                System.out.println("Enter format: ");
                format = scan.next();
                addNewItem(title, format);
            } else if (menuOption == 2) {
                System.out.println("Enter the item title");
                title = scan.next();
                System.out.println("Who are you loaning it to?");
                loanedTo = scan.next();
                System.out.println("When did you loan it to them?");
                dateLoaned = scan.next();
                markItemOnLoan(title, loanedTo, dateLoaned);
            } else if (menuOption == 3) {
                for (MediaItem mi : items) {
                    System.out.println(mi.getTitle() + ", " + mi.getFormat());
                }
            } else if (menuOption == 4) {

            } else {
                System.exit(1);
            }

        } while (!right);
    }

    static int displayMenu() {
        boolean right = false;

        do {

            System.out.println("Menu: ");
            System.out.println("1. Add New Item");
            System.out.println("2. Mark an item as on loan");
            System.out.println("3. List all items");
            System.out.println("4. Mark an item as returned");
            System.out.println("5. Quit");
            menuOption = scan.nextInt();

            if (menuOption < 1 || menuOption > 5) {
                System.out.println("Invalid Number!");
            }

            return menuOption;
        } while (!right);
    }

    static void addNewItem(String title, String format) {
        MediaItem b = new MediaItem();
        b.setTitle(title);
        b.setFormat(format);
        items.add(b);

    }

    static void markItemOnLoan(String title, String name, String date) {
        Iterator<MediaItem> it = items.iterator();
        System.out.println(it.next());
    }

}





public class MediaItem {

String title;
    String format;
    boolean onLoan;
    String loanedTo;
    String dateLoaned;

    MediaItem() {
        title = null;
        format = null;
        onLoan = false;
        loanedTo = null;
        dateLoaned = null;

    }

    MediaItem(String title, String format) {
        title = new String();
        format = new String();

    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getFormat() {
        return format;
    }

    public void setFormat(String format) {
        this.format = format;
    }

    public boolean isOnLoan() {
        return onLoan;
    }

    public void setOnLoan(boolean onLoan) {
        this.onLoan = onLoan;
    }

    public String getLoanedTo() {
        return loanedTo;
    }

    public void setLoanedTo(String loanedTo) {
        this.loanedTo = loanedTo;
    }

    public String getDateLoaned() {
        return dateLoaned;
    }

    public void setDateLoaned(String dateLoaned) {
        this.dateLoaned = dateLoaned;
    }

    void markOnLoan(String name, String date) {
        onLoan = true;
    }

    void markReturned() {
        onLoan = false;
    }
}

Answer 1

The MediaItem@3c4568f8 output is the result of Object's toString() method.

[T]his method returns a string equal to the value of:

getClass().getName() + '@' + Integer.toHexString(hashCode())

You haven't overridden toString() in Media, so it inherits the method from Object.

Override toString(), returning the string that you want printed when your object is passed to System.out.println and string conversion calls toString() on your Object.

Answer 2

You should implement a toString() method that will return the something like title instead of the object reference. Also, you can implement a comparator to accurately determine if the objects match.