Question

This is my java method that is suppose to take data from a file(String, String, Double, Int ) and load that data into an object array. This is what I have and when I try to display the contents of this array it prints a "@" then some numbers and letters. which is not the correct output. any help correcting my method would be much appreciated.

public void loadInventory(String fileName) {

String inFileName = fileName;

String id = null;

String name = null;

double price = 0;

int quantity = 0;

int count = 0;

try {

Scanner infile = new Scanner(new FileInputStream(inFileName));

count = 0;

while (infile.hasNext() && count < 100)

{

id = infile.next();

name = infile.next();

price = infile.nextDouble();

quantity = infile.nextInt();

Item newItemList = new Item(id, name, price, quantity);

itemList[count] = newItemList;

++count;

}//end of hasNext loop

infile.close();

}//end of try

catch (IOException ex)

{

count = -1;

System.out.printf("\nNow ya done goofed " + ex +"\n");

}//end of catch

}

Answer 1

Issue:
--------
If the contents of this array it prints a "@" then some numbers and letters.
Then you are tying to print Item object without having a toString() method in the Item class.

In other words, If you do not have toString() method in a class and you are trying to print the object of such class
then it prints the address of object. Address looks like starts with @ and then some numbers and letter.

Fix:
------
Add a toString method in Item class.
Check the example below.



public class Item {
    private String id;
    private String name;
    private double price;
    private int quantity;

    public Item(String id, String name, double price, int quantity) {
        this.id = id;
        this.name = name;
        this.price = price;
        this.quantity = quantity;
    }

    public String toString() {
        return "Item{" +
                "id='" + id + '\'' +
                ", name='" + name + '\'' +
                ", price=" + price +
                ", quantity=" + quantity +
                '}';
    }
}



import java.io.FileInputStream;
import java.io.IOException;
import java.util.Random;
import java.util.Scanner;

public class TestCode {
    static Item itemList[] = new Item[100];
    public static void loadInventory(String fileName) {
        String inFileName = fileName;
        String id = null;
        String name = null;
        double price = 0;
        int quantity = 0;
        int count = 0;
        try {
            Scanner infile = new Scanner(new FileInputStream(inFileName));
            count = 0;
            while (infile.hasNext() && count < 100)
            {
                id = infile.next();
                name = infile.next();
                price = infile.nextDouble();
                quantity = infile.nextInt();
                Item newItemList = new Item(id, name, price, quantity);
                itemList[count] = newItemList;
                ++count;
            }//end of hasNext loop
            infile.close();
        }//end of try
        catch (IOException ex)
        {
            count = -1;
            System.out.printf("\nNow ya done goofed " + ex +"\n");
        }//end of catch
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String fn;
        System.out.println("Enter file name: ");
        fn = scanner.next();
        loadInventory(fn);

        for(int i = 0;i<itemList.length;i++){
            System.out.println(itemList[i]);
        }
    }
}