使用Excel文件中的数据刷新表JTable

Question

I have a code to populate a JTable with data from a Excel File. The problem is that after set data to the JTable, I can´t to repaint the table with the new data. The information charging properly but no refresh the table. I charge the data by a button "Procesar" after that select a file. My code is:

`

import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JFileChooser;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTextField;

import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.File;
import java.io.FileInputStream;
import java.util.Vector;

import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;

import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.awt.Color;
import javax.swing.JTextPane;
import java.awt.TextArea;
import javax.swing.border.MatteBorder;



public class Principal 
{
    private File file;
    Vector header = new Vector();
    Vector data = new Vector();
    DefaultTableModel model = new DefaultTableModel(data,header);

    private JFrame frame;
    private JTextField txtRuta;
    private JButton btnBuscar;
    private JButton btnProcesar;

    private MouseAdapter mouseAdapterBtnBuscar;
    private MouseAdapter mouseAdapterBtnProcesar;
    private JTextPane txtPane = new JTextPane();
    private TextArea textArea;
    private JTable table;


    /**
     * Método principal que lanza la aplicación
     */
    public static void main(String[] args) 
    {
        EventQueue.invokeLater(new Runnable() {
            public void run() 
            {
                try 
                {
                    Principal window = new Principal();
                    window.frame.setVisible(true);
                } 
                catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Constructor de la clase.
     */
    public Principal() {
        initialize();
    }

    /**
     * Inicializa el contenido del Frame visual.
     */
    private void initialize() 
    {
        inicializeHandlers();

        frame = new JFrame();
        frame.setBounds( 100, 100, 613, 592 );
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        frame.getContentPane().setLayout( null );

        btnBuscar = new JButton( "Buscar" );
        btnBuscar.addMouseListener( mouseAdapterBtnBuscar );
        btnBuscar.setBounds(498, 11, 89, 23);
        frame.getContentPane().add( btnBuscar );

        btnProcesar = new JButton( "Procesar" );
        btnProcesar.addMouseListener( mouseAdapterBtnProcesar );
        btnProcesar.setBounds( 498, 40, 89, 23 );
        frame.getContentPane().add( btnProcesar );

        txtRuta = new JTextField();
        txtRuta.setBounds( 10, 12, 478, 20 );
        frame.getContentPane().add( txtRuta );
        txtRuta.setColumns( 10 );

        textArea = new TextArea();
        textArea.setBounds(10, 88, 577, 190);
        frame.getContentPane().add(textArea);

        table = new JTable();
        table.createDefaultColumnsFromModel();

        table.setBorder(new MatteBorder(1, 1, 1, 1, (Color) new Color(0, 0, 0)));
        table.setSurrendersFocusOnKeystroke(true);
        table.setColumnSelectionAllowed(true);
        table.setCellSelectionEnabled(true);
        table.setBounds(10, 321, 577, 190);
        frame.getContentPane().add(table);
    }

    /*Método para controlar los listeners de los componentes.*/
    private void inicializeHandlers()
    {       
        mouseAdapterBtnBuscar = new MouseAdapter() 
        {
            @Override
            public void mouseClicked(MouseEvent arg0) 
            {   
                JFileChooser flsBuscador = new JFileChooser();
                int result = flsBuscador.showOpenDialog(null);

                if ( result == JFileChooser.APPROVE_OPTION )
                {
                    file = flsBuscador.getSelectedFile();
                    txtRuta.setText( file.getAbsolutePath() );
                }
            }
        };

        mouseAdapterBtnProcesar = new MouseAdapter() 
        {
            @Override
            public void mouseClicked(MouseEvent arg0)
            {   
                if ( txtRuta.getText() == null || txtRuta.getText() == "" || txtRuta.getText().endsWith(".xlsx") == false )
                {
                    JOptionPane.showMessageDialog( frame, "La ruta no es correcta o el archivo no es soportado.", "Información", JOptionPane.WARNING_MESSAGE );
                }
                else
                {
                    try
                    {
                        procesarArchivo();
                    }
                    catch( Exception ex )
                    {
                        ex.printStackTrace();
                    }
                }
            }
        };
    }

    private void procesarArchivo() throws Exception
    {
        try
        {
            if ( file != null )
            {
                String text = "Inciando lectura...\n";

                FileInputStream fis = new FileInputStream( file );

                XSSFWorkbook workbook = new XSSFWorkbook(fis);

                XSSFSheet sheet = workbook.getSheetAt(0);

                XSSFRow row;

                textArea.setText( text );

                for ( int i = 6; i < sheet.getPhysicalNumberOfRows(); i ++ )
                {
                    Vector d = new Vector();
                    row = sheet.getRow( i );

                    for ( int j = 0; j < row.getPhysicalNumberOfCells(); j++ )
                    {
                        XSSFCell cell = row.getCell( j );

                        if ( cell != null )
                        {
                            if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC)
                            {
                                if ( HSSFDateUtil.isCellDateFormatted(cell) )
                                {
                                    d.add( cell.getDateCellValue().toString().trim() );
                                    text =  text + cell.getDateCellValue().toString().trim() + "\n";
                                    textArea.setText( text );
                                }
                                else
                                {
                                    d.add( Double.toString( cell.getNumericCellValue() ).trim() );
                                    text =  text + Double.toString( cell.getNumericCellValue() ).trim() + "\n";
                                    textArea.setText( text );
                                }
                            }
                            else
                            {
                                d.add( cell.getStringCellValue().trim() );
                                text = text + cell.getStringCellValue().trim() + "\n";
                                textArea.setText( text );
                            }

                            if ( i == 6 )
                            {
                                header.add(d);
                            }
                        }
                        else
                        {
                            d.add("NULL");
                        }
                    }

                    d.add( "\n" );

                    data.add( d );

                }

                model = new DefaultTableModel(data, header);
                table.setModel(model);

                JScrollPane scroll = new JScrollPane(table);
                frame.getContentPane().add( scroll );

            }
        }
        catch( Exception ex )
        {
            ex.printStackTrace();
        }
    }
}

`

Thanks for your help;

Answer 1

In your procesarArchivo() method... How many times do you want to add a table to frame's content pane?

JScrollPane scroll = new JScrollPane(table);
frame.getContentPane().add( scroll );

In your current code every time btnProcesar is pressed a new JTable is added to frame's content pane. You just can't see it because you don't call revalidate() method:

frame.getContentPane().revalidate();

Form Container.add() javadoc:

This method changes layout-related information, and therefore, invalidates the component hierarchy. If the container has already been displayed, the hierarchy must be validated thereafter in order to display the added component.

If you do call revalidate() method you'll see 2 tables, then 3 and so on and that's not what you want. Don't add a new JTable . Add just one JTable and refresh its TableModel instead.

Some other tips:

• Don't set null layout: frame.getContentPane().setLayout( null ); . Use a LayoutManager instead: Using Layout Managers . It will handle components resizing and its positioning.

• Don't use MouseListener to handle the event when a button is pressed. Use ActionListener instead: How to Use Buttons, Check Boxes, and Radio Buttons

• Read carefully this tutorial: How to Use Tables