Inventory Program part 1 and part 2

// SFInventoryPt1.java
// Inventory keeper for torque tools


import java.util.Scanner; // program uses class Scanner

class ProductInfo // class to store product information
{
ProductInfo(int itemNumber, String itemName, int stockQty, double priceEach) // constructor for product info
{
num = itemNumber;
name = itemName;
stock = stockQty;
price = priceEach;
}

public int getNum()
{
return num;
}
public String getName()
{
return name;
}
public int getStock()
{
return stock;
}
public double getPrice()
{
return price;
}
public double getInventoryTotal()
{
return price * stock;
}

private int num; // product's item number
private String name; // product's item name
private int stock; // number of item in stock
private double price; // price each of item

} // end class ProductInfo

class SFInventoryPt1
{
private String ProductInfo; // call class product info

// main method begins execution of Java application
public static void main ( String args[] )
{
//create Scanner to obtain input from command window
Scanner input = new Scanner( System.in );

int num; // product's item number
int stock; // number of items in stock
double price; // price each of item
ProductInfo product; // product information instance

System.out.println(); // blank line

System.out.print( "Enter the item name of the product, or STOP to quit: "); // prompt
String name = input.nextLine(); // read item name from user or quit

// loop until sentinel value read from user
while ( !name.equalsIgnoreCase ("stop") )
{

System.out.print( "Enter the item number of the product: "); // prompt
num = input.nextInt(); // read item number from user

while ( num <=0 ) //loop until item number is positive
{
System.out.println ("Item number must be positive. Please re-enter item number: ");//prompt user to re-enter item number
num = input.nextInt(); // read item number

} //end while

System.out.print( "Enter the quantity of product in stock: "); // prompt
stock = input.nextInt(); // read stock quantity from user

while ( stock <0 ) //loop until stock is positive
{
System.out.println ("Quantity in stock can not be less than zero. Please re-enter the quantity in stock: ");//prompt user to re-enter quantity in stock
stock = input.nextInt(); // read stock quantity from user

} //end while

System.out.print( "Enter the price of the product: "); // prompt
price = input.nextDouble(); // read item price from user

while ( price <=0 ) //loop until price is positive
{
System.out.println ("Product price must be positive. Please re-enter the price of the product: ");//prompt user to re-enter product price
price = input.nextDouble(); // read item price from user

} //end while

product = new ProductInfo( num, name, stock, price); // initialize ProductInfo variables

System.out.println(); // blank line

System.out.printf( "Item Name: %S\n", product.getName());
System.out.printf( "Item Number: %s\n", product.getNum());
System.out.printf( "Qty. in Stock: %s\n", product.getStock());
System.out.printf( "Price Each: $%.2f\n", product.getPrice());
System.out.printf( "Total Value in Stock: $%.2f\n", product.getInventoryTotal());

System.out.println(); // blank line

System.out.print( "Enter the item name of the product, or STOP to quit: "); // prompt
name = "";
while ( name.equals("") )
{
name = input.nextLine(); // read new product name from user or quit
}

} //end while

System.out.println(); // blank line

System.out.println("Good Bye!"); // exit message


} // end method main

} // end class SFInventoryPt1


This is where my trouble starts. I now need to modify the above code to meet these assignment 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•