java - 使用 Excel 文件中的数据刷新表 JTable

Question

我有一段代码可以用 Excel 文件中的数据填充 JTable。问题是在将数据设置到 JTable 之后，我无法用新数据重新绘制表格。信息收费正常但不刷新表格。选择一个文件后，我通过“Procesar”按钮收取数据。我的代码是:

`

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();
        }
    }
}

`

感谢您的帮助；

Answer 1

在您的 procesarArchivo() 方法中...您想向框架的内容 Pane 添加多少次表格？

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

在您当前的代码中，每次按下 btnProcesar 时，都会将一个新的 JTable 添加到框架的内容 Pane 中。你只是看不到它，因为你没有调用 revalidate()方法:

frame.getContentPane().revalidate();

表格Container.add()文档:

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.

如果您确实调用了 revalidate() 方法，您将看到 2 个表，然后是 3 个，依此类推，这不是您想要的。不要添加新的 JTable。只添加一个 JTable 并刷新它的 TableModel。

一些其他提示:

• 不要设置 null 布局:frame.getContentPane().setLayout( null );。使用 LayoutManager 代替:Using Layout Managers .它将处理组件大小调整及其定位。

• 不要使用 MouseListener 来处理按下按钮时的事件。使用 ActionListener 代替:How to Use Buttons, Check Boxes, and Radio Buttons

• 仔细阅读本教程:How to Use Tables