Thread: Sorting objects of an array by String name

Hello all, I am new to the forums and fairly new to Java so please take it easy on me

I am given this assignment to create an Inventory Program and this is part 2 of the assignment. Here are the requirements:

Modify the Inventory Program so the application can handle multiple items. Use an array to store the items. The output should display the information one product at a time, including the item number, the name of the product, the number of units in stock, the price of each unit, and the value of the inventory of that product. In addition, the output should display the value of the entire inventory.

Create a method to calculate the value of the entire inventory.

Create another method to sort the array items by the name of the product.

I am having a heck of a time trying to figure out how to sort this array by the name of the objects. I have tried both a bubble sort (commented out) and using the compareTo but keep getting errors. I got it down to one error saying I need to make the class InventoryConstruct abstract, but when I do that I get even more errors that pop up. Can someone please help me understand this? I have already looked online for hours trying to figure out what I am doing wrong and I cannot seem to get it right. The assignment is also asking us to do something that is not covered in our materials and this is an online course... can't get a real timely response from my instructor. Here is the code:

import java.util.Arrays;
 
public class InventoryProduct
{
	//main method starts execution
	public static void main (String[] args)
	{
		//welcome message
		System.out.println("Welcome to the inventory tracker!\n ");
 
		//inventory information
		InventoryConstruct[] software = new InventoryConstruct[4];
 
		InventoryConstruct p1 = new InventoryConstruct(1, "FL Studio ", 99.99, 14);
		InventoryConstruct p2 = new InventoryConstruct(2, "Reason ", 149.99, 5);
		InventoryConstruct p3 = new InventoryConstruct(3, "Ableton Live ", 399.99, 8);
		InventoryConstruct p4 = new InventoryConstruct(4, "Pro Tools ", 299.99, 6);
 
		software[0] = p1;
		software[1] = p2;
		software[2] = p3;
		software[3] = p4;
 
		Arrays.sort(software, InventoryConstruct.InventorySort);
 
		for (int i = 0; i < 4; i++ )
		{
			System.out.println("ID#: " + ++i + "   Name: " + InventoryConstruct.getName() 
					+ "   Price: " + InventoryConstruct.getPrice() + "   In Stock: " + InventoryConstruct.getStock());
		}
		/*sort (software[] software)
		{
			for (int a = 1; a < software.length; a++)
			{
				for (int b = 0; b < software.length - a; b++)
				{
					if (((software[b].getName()).compareToIgnoreCase((software[b+1].getName()))) > 0)
					{
						InventoryConstruct temp = software[b];
						software[b] = software[b + 1];
						software[b + 1] = temp;
					}
				}
			}
		}
 
		//display ID number
		System.out.printf("Product ID number: %d%n", software.getName());
		//display product name
		System.out.printf("Product name: %s%n", p1.getName());
		//display product price
		System.out.printf("The item's price is: $%.2f%n", p1.getPrice());
		//display amount in stock
		System.out.printf("Amount in stock: %d%n%n", p1.getStock());
		//display inventory total
		System.out.printf("The total value of inventory is: $%.2f", p1.getTotal());
	}*/
	}//end main
}//end class

import java.util.Comparator;
 
public class InventoryConstruct implements Comparable<InventoryConstruct>
{
	private int itemNum;//declare ID number
	private static String itemName;//declare item name
	private static double itemPrice;//declare item price
	private static int itemInStock;//declare amount in stock
	private static double inventoryTotal;//declare total of inventory product
 
	//initialize constructor
	public InventoryConstruct(int itemNum, String itemName,             
			double itemPrice, int itemInStock)
	{
		this.itemNum = itemNum;
		InventoryConstruct.itemName = itemName;
		InventoryConstruct.itemPrice = itemPrice;
		InventoryConstruct.itemInStock = itemInStock;
		setTotal();
	}
	//return ID number
	public int getNum()
	{
		return itemNum;
	}
	//return item name
	public static String getName()
	{
		return itemName;
	}
	//return item price
	public static double getPrice()
	{
		return itemPrice;
	}
	//return amount in stock
	public static int getStock()
	{
		return itemInStock;
	}
	//calculate total
	public void setTotal()
	{
		inventoryTotal = itemPrice * itemInStock;
	}
	//return total
	public double getTotal()
	{
		return inventoryTotal;
	}
 
	public static Comparator<InventoryConstruct> InventorySort
		= new Comparator<InventoryConstruct>()
	{
		public int compare(InventoryConstruct software1, InventoryConstruct software2)
		{
			String itemName1 = InventoryConstruct.getName().toUpperCase();
			String itemName2 = InventoryConstruct.getName().toUpperCase();
 
			return itemName1.compareTo(itemName2);
		}
	};
 
}//end class

Any assistance would be GREATLY appreciated...

This is what is printing out in the compiler when I run it (with errors)

Welcome to the inventory tracker!

ID#: 1 Name: Pro Tools Price: 299.99 In Stock: 6
ID#: 3 Name: Pro Tools Price: 299.99 In Stock: 6

Edit: I got it to print this out now (still with errors):

Welcome to the inventory tracker!

ID#: 1 Name: Pro Tools Price: 299.99 In Stock: 6
ID#: 2 Name: Pro Tools Price: 299.99 In Stock: 6
ID#: 3 Name: Pro Tools Price: 299.99 In Stock: 6
ID#: 4 Name: Pro Tools Price: 299.99 In Stock: 6

by changing it to for(i = 1; i <= 4; i++) and taking the increment off the print statement, but it is still printing only one of the object's info and I have no clue if the sort code is correct because of this.

Does it compile?

In either case post the full text of the error messages

Originally Posted by jps

Does it compile?

In either case post the full text of the error messages

Yes it does compile, but it doesn't print correctly. The only error I am getting is that I need to add unimplimented methods to InventoryConstruct (I know my naming sucks and I will change it and redo everything once I figure this out) so when I click the line to add that it adds this at the end:

	@Override
	public int compareTo(InventoryConstruct o) {
		// TODO Auto-generated method stub
		return 0;

which leads me to believe there is something wrong with this line of my code:

 public int compare(InventoryConstruct software1, InventoryConstruct software2)