java - TableModelListener 和多列验证

Question

第一次在这里发帖，如有错误请见谅

我正在处理一个 JTable，其中的列数据必须验证一些参数，例如:

第 3 列值 > 30
第 4 列值 > 10
第 5 列值 > 4

前 2 列也是“自动”填充的，其余列为 0。

如果该数据正确，我将在第 5 列中显示勾号图像，否则，我将显示警告图像。

为了验证这一点，我使用以下代码

    ImageIcon accept = new javax.swing.ImageIcon(getClass().getResource("/resources/accept.png"));
    ImageIcon deny = new javax.swing.ImageIcon(getClass().getResource("/resources/exclamation.png"));

    public void tableChanged(TableModelEvent e) {
        int row = e.getFirstRow();
        double d1 = Double.valueOf(jTable.getValueAt(row, 2).toString());
        double d2 = Double.valueOf(jT.getValueAt(row, 3).toString());
        double d3 = Double.valueOf(jT.getValueAt(row, 4).toString());

        if(d1>MAX_A||d2>MAX_B||d3>MAX_C){
            jTable.setValueAt(deny, row, 5);
        }
        else{
            jTable.setValueAt(accept, row, 5);
        }
    }

这段代码的问题是返回 Stack Overflow，我不知道如何处理。

是否有任何其他方法可以在暗示多个单元格的表上实现一些 validator ？

提前致谢。

Answer 1

The problem of this code is thatreturns a Stack Overflow, and I don'tknow how to handle this.

问题是您的代码在模型监听器中设置了一个值，因此生成了另一个 tableChanged 事件。你的代码应该是这样的:

if (e.getColumn() != 5)
   // do your code

我没有发现使用 TableModelListener 根据另一列中的数据动态设置列值的问题。这是一个简单的例子:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.table.*;

public class TableProcessing extends JPanel implements TableModelListener
{
    public TableProcessing()
    {
        String[] columnNames = {"Item", "Quantity", "Price", "Cost"};
        Object[][] data =
        {
            {"Bread", new Integer(1), new Double(1.11), new Double(1.11)},
            {"Milk", new Integer(1), new Double(2.22), new Double(2.22)},
            {"Tea", new Integer(1), new Double(3.33), new Double(3.33)},
            {"Cofee", new Integer(1), new Double(4.44), new Double(4.44)}
        };

        DefaultTableModel model = new DefaultTableModel(data, columnNames)
        {
            //  Returning the Class of each column will allow different
            //  renderers to be used based on Class
            @Override
            public Class getColumnClass(int column)
            {
                return getValueAt(0, column).getClass();
            }

            //  The Cost is not editable
            @Override
            public boolean isCellEditable(int row, int column)
            {
                return (column == 3) ? false : true;
            }
        };
        model.addTableModelListener( this );

        JTable table = new JTable( model );
        table.setPreferredScrollableViewportSize(table.getPreferredSize());

        JScrollPane scrollPane = new JScrollPane( table );
        add( scrollPane );

        String[] items = { "Bread", "Milk", "Tea", "Coffee" };
        JComboBox<String> editor = new JComboBox<String>( items );

        DefaultCellEditor dce = new DefaultCellEditor( editor );
        table.getColumnModel().getColumn(0).setCellEditor(dce);
    }

    /*
     *  The cost is recalculated whenever the quantity or price is changed
     */
    public void tableChanged(TableModelEvent e)
    {
        if (e.getType() == TableModelEvent.UPDATE)
        {
            int row = e.getFirstRow();
            int column = e.getColumn();

            if (column == 1 || column == 2)
            {
                TableModel model = (TableModel)e.getSource();
                int quantity = ((Integer)model.getValueAt(row, 1)).intValue();
                double price = ((Double)model.getValueAt(row, 2)).doubleValue();
                Double value = new Double(quantity * price);
                model.setValueAt(value, row, 3);
            }
        }
    }

    private static void createAndShowGUI()
    {
        JFrame frame = new JFrame("Table Model Listener");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new TableProcessing());
        frame.pack();
        frame.setLocationByPlatform( true );
        frame.setVisible( true );
    }

    public static void main(String[] args) throws Exception
    {
        EventQueue.invokeLater( () -> createAndShowGUI() );
/*
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowGUI();
            }
        });
*/
    }
}