如何在 JTable Java 中创建求和行

Question

我在某处有堆栈

帮助我创建行来计算第 1 列中的一些值。 5

我使用下面的模型，但我未能创建一行来总结第五列中的数据，如果有人知道如何，请帮助我。

当数据从按钮触发时，我也需要增加行数以及最后一行的总数

提前谢谢您。

我

setModel ( new DefaultTableModel () {
            private static final long serialVersionUID = 1L;
            private final String[] columnNames = { "" , "" , "" , "" , "" , "" };

            @Override
            public Class<?> getColumnClass ( int columnIndex ) {
                switch ( columnIndex ) {
                    case 3:
                    case 4:
                    case 5:
                        return Double.class;
                }
                return super.getColumnClass ( columnIndex );
            }

            @Override
            public Object getValueAt ( int row ,
                    int column ) {
                if ( column == 5 ) {
                    Double i = ( Double ) getValueAt ( row ,
                            3 );
                    Double d = ( Double ) getValueAt ( row ,
                            4 );

                    if ( i != null && d != null ) {
                        return i * d;
                    } else {

                    }
                }
                return super.getValueAt ( row ,
                        column );
            }

            @Override
            public boolean isCellEditable ( int row ,
                    int column ) {
                return column == 1 || column == 2 || column == 3 || column == 4;

            }

            @Override
            public void setValueAt ( Object aValue ,
                    int row ,
                    int column ) {
                super.setValueAt ( aValue ,
                        row ,
                        column );
                fireTableCellUpdated ( row ,
                        5 );
            }

            @Override
            public String getColumnName ( int column ) {
                switch ( column ) {
                    case 0:
                        return "S/N";
                    case 1:
                        return "Product";
                    case 2:
                        return "UoM";
                    case 3:
                        return "Quantity";
                    case 4:
                        return "Price";
                    case 5:
                        return "Total";

                }
                return super.getColumnName ( column );
            }

            @Override
            public int getColumnCount () {
                return columnNames.length;
            }

        } );

        setTable ( new JTable ( getModel () ) );
        getTable ().
                setFillsViewportHeight ( true );
        getTable ().
                addMouseListener ( new MouseAdapter () {

                    @Override
                    public void mouseClicked ( MouseEvent e ) {
                        if ( e.getClickCount () == 1 ) {
                            if ( getTable ().
                                    rowAtPoint ( e.getPoint () ) < 0 ) {
                                getModel ().
                                        addRow ( new Vector () );
                                model.setValueAt ( getLine () + 1 ,
                                        getLine () ,
                                        0 );
                                setLine ( getLine () + 1 );

                            }
                        }
                    }
                } );

        tcm = table.getColumnModel ();
        tc1 = tcm.getColumn ( 0 );
        tc2 = tcm.getColumn ( 2 );
        tc1.setMaxWidth ( 100 );
        tc2.setMaxWidth ( 100 );

        getTable ().
                setRowHeight ( getTable ().
                        getRowHeight () + 15 );
        getTable ().
                getTableHeader ().
                setFont ( new Font ( "Arial" ,
                        Font.BOLD ,
                        18 ) );
        table.setFont ( new Font ( "Arial" ,
                Font.PLAIN ,
                18 ) );
        getTable ().
                setGridColor ( new java.awt.Color ( 150 ,
                        150 ,
                        150 ) );
        table.setForeground ( new java.awt.Color ( 0 ,
                0 ,
                0 ) );
        table.setBackground ( Color.WHITE );
        table.getTableHeader ().
                setBackground ( new java.awt.Color ( 60 ,
                        130 ,
                        160 ) );
        table.getTableHeader ().
                setForeground ( new java.awt.Color ( 255 ,
                        255 ,
                        255 ) );

        getTd ().
                setBackground ( new java.awt.Color ( 60 ,
                        130 ,
                        160 ) );
        getTd ().
                setForeground ( Color.WHITE );
        getTd ().
                setFont ( new Font ( "Arial" ,
                        Font.PLAIN ,
                        20 ) );

        getBtn1 ().
                setBackground ( new java.awt.Color ( 60 ,
                        130 ,
                        160 ) );
        getBtn1 ().
                setFont ( new Font ( "Arial" ,
                        Font.BOLD ,
                        20 ) );
        getBtn1 ().
                setForeground ( new java.awt.Color ( 250 ,
                        250 ,
                        250 ) );
        getBtn2 ().
                setBackground ( new java.awt.Color ( 60 ,
                        130 ,
                        160 ) );
        getBtn2 ().
                setFont ( new Font ( "Arial" ,
                        Font.BOLD ,
                        20 ) );
        getBtn2 ().
                setForeground ( new java.awt.Color ( 250 ,
                        250 ,
                        250 ) );
        getBtn4 ().
                setBackground ( new java.awt.Color ( 60 ,
                        130 ,
                        160 ) );
        getBtn4 ().
                setFont ( new Font ( "Arial" ,
                        Font.BOLD ,
                        20 ) );
        getBtn4 ().
                setForeground ( new java.awt.Color ( 250 ,
                        250 ,
                        250 ) );
        getBtn5 ().
                setBackground ( new java.awt.Color ( 60 ,
                        130 ,
                        160 ) );
        getBtn5 ().
                setFont ( new Font ( "Arial" ,
                        Font.BOLD ,
                        20 ) );
        getBtn5 ().
                setForeground ( new java.awt.Color ( 250 ,
                        250 ,
                        250 ) );

        getBtn4 ().
                addActionListener ( ( ActionEvent e ) -> {
                    saveTable ();
                } );
        getBtn1 ().
                addActionListener ( ( ActionEvent e ) -> {
                    loadTable ();
                } );
        getBtn2 ().
                addActionListener ( ( ActionEvent e ) -> {
                    getModel ().
                            addRow ( new Vector () );
                    double total = 0;
                    model.setValueAt ( total ,
                            model.getRowCount () - 1 ,
                            5 );
                    model.setValueAt ( getLine () + 1 ,
                            getLine () ,
                            0 );
                    setLine ( getLine () + 1 );
                } );

        getBtn5 ().
                addActionListener ( new ActionListener () {
                    @Override
                    public void actionPerformed ( ActionEvent e ) {
                        MessageFormat header = new MessageFormat ( "INVOICE" );
                        MessageFormat footer = new MessageFormat ( "-{0}-\n" + new Date () );
                        try {
                            table.print ( JTable.PrintMode.FIT_WIDTH ,
                                    header ,
                                    footer );
                        } catch ( Exception ae ) {
                            System.err.println ( "Error printing: " + ae.getMessage () );

                        }
                    }
                } );

        getJb ().
                add ( getBtn5 () );
        getJb ().
                add ( getBtn1 () );
        getJb ().
                add ( getBtn4 () );
        getJb ().
                add ( getBtn2 () );

        setScrollPane2 ( new JScrollPane ( getTable () ) );

        frame.add ( getScrollPane2 () ,
                BorderLayout.CENTER );
        frame.add ( getTd () ,
                BorderLayout.NORTH );
        frame.add ( getJb () ,
                BorderLayout.SOUTH );
        frame.setDefaultCloseOperation ( EXIT_ON_CLOSE );
        frame.pack ();
        frame.setSize ( 1300 ,
                900 );
        frame.setLocationRelativeTo ( null );
        frame.setVisible ( true );

  The image can be viewed here 

Answer 1

首先，您应该避免将汇总行作为表的最后一行，因为您将更改数据模型。如果您从模型中添加/删除行，这将避免移动行的需要。 话虽这么说，您可以轻松地将总计放入 JLabel 或其他组件中。 只需添加一个 TableModelListener 即可捕获模型中的更改并重新计算总数：

dataTable.getModel().addTableModelListener(new TableModelListener() {
    @Override
    public void tableChanged(TableModelEvent e) {
        updateSummary();
    }
});

private void updateSummary(){
    Double sum = (double) 0;
    for (int row = 0; row < dataTable.getRowCount(); row++){
        int rowModel = dataTable.convertRowIndexToModel(row);
        // Make sure the cast is possible here, or convert the Object appropiately to Double
        Double value = (Double) tblResults.getModel().getValueAt(rowModel, 5);
        sum += value;
    }
    // Format the number appropiately here if you need
    lblSummary.setText(sum.toString());
}

即使您有 RowFilter，此方法也将起作用，因为它适用于所有可见行。