This is my code, I could get the program to run before i tried to get it to display using a GUI interface; can anyone help please?
//Inventory Program Part5

import java.util.*; //=============================import all java.util classes
import java.text.*;
import javax.swing.*;

class Product //============================================start Product class
{
public String[] className; //=====================================class's name
public int[] classNumber; //=====================class's unique product number
public int[] classQuantity; //=======================class's quantity in stock
public double[] classPrice; //===============================class's price per

public Product(String[] name, int[] number, int[] quantity, double[] price)
//==========================================================product constructor
{
className = name; //==============================set className to name
classNumber = number; //======================set classNumber to number
classQuantity = quantity; //==============set classQuantity to quantity
classPrice = price; //==========================set classPrice to price
} //====================================================end Product constructor

public Product SortedArray(Product Inventory5) //======start method SortedArray
{
String[] name=new String[Inventory5.className.length];
//=================================================new name for sorting array
int [] number = new int[Inventory5.classNumber.length];
//===============================================new number for sorting array
int[] quantity = new int[Inventory5.classQuantity.length];
//=============================================new quantity for sorting array
double [] price = new double [Inventory5.classPrice.length];
//=================================================new price for sorting array
name = (String[])Inventory5.className.clone();
//=================================================place name in sorting array
Arrays.sort(name); //=============================================sort by name
for (int counter = 0; counter < name.length; counter++)
//==========================================loop and counter for sorting array
{
for(int counter2=0;counter2<name.length;counter2++)
//====================loop and counter to match unsorted array and sorted one
{
if(name[counter].equals(Inventory5.className[counter2]))
//=====================================if statement for when a match occurs
{
quantity[counter]=Inventory5.classQuantity[counter2];
//=============================set quantity equal to sorted array quantity
price[counter]=Inventory5.classPrice[counter2];
//===================================set price equal to sorted array price
number[counter]=Inventory5.classNumber[counter2];
//=================================set number equal to sorted array number
break; //============================================break for if statement
} //========================================================end if statement

} //====================================================end for loop counter2

} //======================================================end for loop counter
Product SortedProductArray = new Product (name, number, quantity, price);
//=========================new sorted product array replace old product array
return SortedProductArray; //==================return new product array sorted
} //=====================================================end method SortedArray

public double TotalInvWorth(int[] quantity, double[] price)
//=====start method TotalInvWorth
{
double total=0.00F; //====================================set double total = 0
for (int counter = 0; counter < quantity.length; counter++)
//================loop and counter to multiply each quantity x price in array
{
double perprodworth=quantity[counter]*price[counter];
//============= multiply quantity x price per counter in array = perprodworth
total=total+perprodworth; //=========================add perprodworth to total
}
return total; //==================================return total in TotalInvWorth
} //===================================================end method TotalInvWorth

} //===========================================================end Product class
public class Inventory5 extends JFrame
{
JTextArea _resultArea = new JTextArea(20,40);
//=================================================== start class Inventory5
public static void main(String[] args) //==============start main method
{
//=========================setting static data for variables in each array
String[] name = {"Java Programming IT", "Internet Concepts IT",
"Analysis & Design IT", "Computer Networking IT"};
int[] number = {315, 320, 321, 330};
int[] quantity = {1, 1, 1, 1};
double[] price = {(double) 855.00, (double) 855.00, (double) 855.00,
(double) 855.00};

Product Inventory5 = new Product (name, number, quantity, price);
//=========================================needed to resolve constructor

JOptionPane.showMessageDialog(null, "Course Name: " className,
"\nCourseID: " classNumber, "\n Price of Remaining Class: $"
classPrice, "\nTotal of Remaining Courses: $" TotalInvWorth,
JOptionPane.PLAIN_MESSAGE);


} //========================================================end main method

} //======================================================= end class Inventory5