Alteração de lista a partir de uma importação de excel APCHE POI

[Rodrigo_Prado1]

O sistema pode gerar um arquivo excel onde se encontram todos os produtos de um estoque serializados. O que gostaria é que quando esse arquivo for importado de volta que todas alterações feitas nele sejam aplicadas dentro do sistema. Segue exemplo minimo verificável do que consegui fazer até agora

import java.awt.Label;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.swing.JFileChooser;
import javax.swing.JFormattedTextField;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.filechooser.FileFilter;
import javax.swing.table.AbstractTableModel;

import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;

public class MinimoVerificavel
{
	public class Products
	{
		private int code;
		private String name;
		private float cost;
		private float price;
		private float netProfit;

		public int getCode()
		{
			return code;
		}

		public void setCode(int code)
		{
			this.code = code;
		}

		public String getName()
		{
			return name;
		}

		public void setName(String name)
		{
			this.name = name;
		}

		public float getCost()
		{
			return cost;
		}

		public void setCost(float cost)
		{
			this.cost = cost;
		}

		public float getPrice()
		{
			return price;
		}

		public void setPrice(float price)
		{
			this.price = price;
		}

		public float getNetProfit()
		{
			return netProfit;
		}

		public void setNetProfit(float netProfit)
		{
			this.netProfit = netProfit;
		}
	}

	// -------------------------------------------------------------------------------------------------------------
	public interface Dao<P>
	{
		public void change(P obj) throws Exception;
	}

	// -------------------------------------------------------------------------------------------------------------
	public class Change implements Dao<Products>
	{
		private List<Products> productsList = new ArrayList<>();

		@Override
		public void change(Products obj) throws Exception
		{
			int code = obj.getCode();

			for (Products search : productsList)
			{
				if (search.getCode() == code)
				{
					search.setName(obj.getName());
					search.setCost(obj.getCost());
					search.setPrice(obj.getPrice());
					search.setNetProfit(obj.getNetProfit());

					productsList.add(search);
				}
			}
		}
	}

	// -------------------------------------------------------------------------------------------------------------
	@SuppressWarnings("serial")
	public class ModelTableProduts extends AbstractTableModel
	{
		private List<Products> products = new ArrayList<>();

		public ModelTableProduts(List<Products> list)
		{
			products = list;
		}

		@Override
		public String getColumnName(int column)
		{
			switch (column)
			{
				case 0:
					return "Cod";
				case 1:
					return "Nome";
				case 2:
					return "Custo";
				case 3:
					return "Preço";
				case 4:
					return "Lucro";
			}
			return super.getColumnName(column);
		}

		@Override
		public int getColumnCount()
		{
			return 5;
		}

		@Override
		public int getRowCount()
		{
			return products.size();
		}

		@Override
		public Object getValueAt(int row, int column)
		{
			Products p = products.get(row);
			switch (column)
			{
				case 0:
					return p.getCode();
				case 1:
					return p.getName();
				case 2:
					return p.getCost();
				case 3:
					return p.getPrice();
				case 4:
					return p.getNetProfit();
				default:
					return null;
			}
		}
	}

	// -------------------------------------------------------------------------------------------------------------
	@SuppressWarnings("serial")
	public class FrameMinimo extends JFrame
	{
		// Menu
		private JMenuBar menuBar;
		private JMenu menu;
		private JMenuItem exp;
		private JMenuItem imp;

		// Cod
		private Label lblCode;
		private JFormattedTextField ftCode;

		// Name
		private JLabel lblName;
		private JTextField txtName;

		// Cost
		private JLabel lblCost;
		private JFormattedTextField ftCost;

		// Price
		private JLabel lblPrice;
		private JFormattedTextField ftPrice;

		// Net profit
		private JLabel lblNetProfit;
		private JFormattedTextField ftNetProfit;

		// table
		private JTable table;
		private JScrollPane scroll;

		// List
		private List<Products> productsList = new ArrayList<>();

		// DAO
		private Dao<Products> dao = new Change();

		public FrameMinimo()
		{
			components();
			events();
			addProduct();
			buildTable();
		}

		private void components()
		{
			setTitle("Importar Excel e alterar");
			setSize(655, 300);
			setLocationRelativeTo(null);
			setLayout(null);
			setResizable(false);
			setDefaultCloseOperation(EXIT_ON_CLOSE);

			// Menu
			menuBar = new JMenuBar();
			menuBar.setFont(getFont());
			setJMenuBar(menuBar);

			menu = new JMenu("Menu");
			menu.setFont(getFont());
			menuBar.add(menu);

			exp = new JMenuItem("Exportar");
			exp.setFont(getFont());
			menu.add(exp);

			imp = new JMenuItem("Importar");
			imp.setFont(getFont());
			menu.add(imp);

			// cod
			lblCode = new Label("Cod");
			lblCode.setFont(getFont());
			lblCode.setSize(50, 25);
			lblCode.setLocation(10, 10);
			add(lblCode);
			ftCode = new JFormattedTextField();
			ftCode.setFont(getFont());
			ftCode.setSize(50, 25);
			ftCode.setLocation(10, lblCode.getY() + lblCode.getHeight());
			ftCode.setEditable(false);
			add(ftCode);

			// Name
			lblName = new JLabel("Nome");
			lblName.setFont(getFont());
			lblName.setSize(50, 25);
			lblName.setLocation(10, ftCode.getY() + ftCode.getHeight());
			add(lblName);
			txtName = new JTextField();
			txtName.setFont(getFont());
			txtName.setSize(300, 25);
			txtName.setLocation(10, lblName.getY() + lblName.getHeight());
			txtName.setEditable(false);
			add(txtName);

			// Cost
			lblCost = new JLabel("Custo");
			lblCost.setFont(getFont());
			lblCost.setSize(50, 25);
			lblCost.setLocation(txtName.getX() + txtName.getWidth() + 10, ftCode.getY() + ftCode.getHeight());
			add(lblCost);
			ftCost = new JFormattedTextField();
			ftCost.setFont(getFont());
			ftCost.setSize(100, 25);
			ftCost.setLocation(txtName.getX() + txtName.getWidth() + 10, lblCost.getY() + lblCost.getHeight());
			ftCost.setEditable(false);
			add(ftCost);

			// Price
			lblPrice = new JLabel("Preço");
			lblPrice.setFont(getFont());
			lblPrice.setSize(50, 25);
			lblPrice.setLocation(ftCost.getX() + ftCost.getWidth() + 10, ftCode.getY() + ftCode.getHeight());
			add(lblPrice);
			ftPrice = new JFormattedTextField();
			ftPrice.setFont(getFont());
			ftPrice.setSize(100, 25);
			ftPrice.setLocation(ftCost.getX() + ftCost.getWidth() + 10, lblPrice.getY() + lblPrice.getHeight());
			ftPrice.setEditable(false);
			add(ftPrice);

			// Net profit
			lblNetProfit = new JLabel("Lucro liquido");
			lblNetProfit.setFont(getFont());
			lblNetProfit.setSize(100, 25);
			lblNetProfit.setLocation(ftPrice.getX() + ftPrice.getWidth() + 10, ftCode.getY() + ftCode.getHeight());
			add(lblNetProfit);
			ftNetProfit = new JFormattedTextField();
			ftNetProfit.setFont(getFont());
			ftNetProfit.setSize(100, 25);
			ftNetProfit.setLocation(ftPrice.getX() + ftPrice.getWidth() + 10, lblNetProfit.getY() + lblNetProfit.getHeight());
			ftNetProfit.setEditable(false);
			add(ftNetProfit);

			// Table
			table = new JTable();
			scroll = new JScrollPane(table);
			scroll.setSize(631, 103);
			scroll.setLocation(10, txtName.getY() + txtName.getHeight() + 5);
			add(scroll);

		}

		private void buildTable()
		{
			ModelTableProduts modelTableProduts = new ModelTableProduts(productsList);
			table.setModel(modelTableProduts);
		}

		private void exp()
		{
			HSSFWorkbook workbook = new HSSFWorkbook();
			HSSFSheet sheet = workbook.createSheet("Estoque");
			File file = new File("Estoque.xls");
			JFileChooser chooser = new JFileChooser();

			// Chooser properties
			chooser.setDialogTitle("Exportar para XLS");
			chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
			chooser.setFileFilter(null);

			chooser.setFileFilter(new FileFilter()
			{
				@Override
				public String getDescription()
				{
					return "XLS File";
				}

				@Override
				public boolean accept(File f)
				{
					return f.getName().toLowerCase().endsWith("xls");
				}
			});

			int action = chooser.showSaveDialog(null);

			if (action == JFileChooser.APPROVE_OPTION)
			{
				file = chooser.getSelectedFile();
				String fileString = file.toString();

				if (fileString.toLowerCase().endsWith("xls") == false)
				{
					fileString += ".xls";
					file = new File(fileString);
				}
			}

			int index = 0;

			for (Products products : productsList)
			{
				HSSFRow row = sheet.createRow(index);
				row.createCell(0).setCellValue(products.getCode());
				row.createCell(1).setCellValue(products.getName());
				row.createCell(2).setCellValue(products.getCost());
				row.createCell(3).setCellValue(products.getPrice());
				row.createCell(4).setCellValue(products.getNetProfit());

				index++;
			}

			try
			{
				workbook.write(file);
				workbook.close();

				System.out.println("Exportado!");
			}
			catch (IOException e)
			{
				e.printStackTrace();
			}
		}

		private void imp() throws IOException
		{

			File file = null;
			Products sameProduct = null;

			JFileChooser chooser = new JFileChooser();
			chooser.setDialogTitle("Importar Arquivos XLS");
			chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
			chooser.setFileFilter(null);

			int showOpenDialog = chooser.showOpenDialog(chooser.getParent()); // Stores user choice

			if (showOpenDialog == JFileChooser.APPROVE_OPTION) // Checks the user's choice
			{
				file = chooser.getSelectedFile(); // Get the file way if approved
			}

			FileInputStream fis = new FileInputStream(file); // Points to an instance of the file

			HSSFWorkbook workbook = new HSSFWorkbook(fis); // Passing FIS to workbook representation

			HSSFSheet sheet = workbook.getSheetAt(0); // Pick the page to be used

			// TODO
			Products product = sameProduct;

			Iterator<Row> iterator = sheet.iterator();

			while (iterator.hasNext())
			{
				HSSFRow row = (HSSFRow) iterator.next();

				Iterator<Cell> cellIterator = row.cellIterator();

				while (cellIterator.hasNext())
				{
					// FIXME
				}
			}

			try
			{
				dao.change(product); // Correct?
			}
			catch (Exception e)
			{
				e.printStackTrace();
			}
		}

		private void addProduct()
		{
			Products p1 = new Products();
			p1.setCode(1);
			p1.setName("Teste 1");
			p1.setCost(50);
			p1.setPrice(100);
			p1.setNetProfit(50);
			productsList.add(p1);

			Products p2 = new Products();
			p2.setCode(2);
			p2.setName("Teste 2");
			p2.setCost(50);
			p2.setPrice(100);
			p2.setNetProfit(50);
			productsList.add(p2);

			Products p3 = new Products();
			p3.setCode(3);
			p3.setName("Teste 3");
			p3.setCost(50);
			p3.setPrice(100);
			p3.setNetProfit(50);
			productsList.add(p3);

			Products p4 = new Products();
			p4.setCode(4);
			p4.setName("Teste 4");
			p4.setCost(50);
			p4.setPrice(100);
			p4.setNetProfit(50);
			productsList.add(p4);

			Products p5 = new Products();
			p5.setCode(5);
			p5.setName("Teste 5");
			p5.setCost(50);
			p5.setPrice(100);
			p5.setNetProfit(50);
			productsList.add(p5);
		}

		private void events()
		{
			exp.addActionListener(new ActionListener()
			{
				@Override
				public void actionPerformed(ActionEvent e)
				{
					exp();
				}
			});

			imp.addActionListener(new ActionListener()
			{
				@Override
				public void actionPerformed(ActionEvent e)
				{
					try
					{
						imp();
					}
					catch (IOException e1)
					{
						// TODO Auto-generated catch block
						e1.printStackTrace();
					}
				}
			});
		}

	}

	public static void main(String[] args)
	{
		MinimoVerificavel mv = new MinimoVerificavel();
		FrameMinimo fm = mv.new FrameMinimo();
		fm.setVisible(true);
	}
}