java - 动态添加数据到 AbstractTableModel 的扩展类

Question

我有一些数据从我的数据库加载并作为公共(public)静态列表存储在另一个类中，我无法访问 MyTableModel 类中的数据以在 jtable 中存储和查看它们...还有许多其他方法可以用我的数据填充表格，但它们没有给我列复选框...我应该做什么？

    class MyTableModel extends AbstractTableModel {
    private String[] columnNames = {"UserName","Admin","Blocked"};
    private Object[Size][3] data;
    //size is an variable thing witch i get it from db,uses as number of the row;
    public int getColumnCount() {
       return columnNames.length;
    }

    public int getRowCount() {
       return data.length;
    }

    public String getColumnName(int col) {
       return columnNames[col];
    }

    public Object getValueAt(int row, int col) {
       return data[row][col];
    }

    public Class getColumnClass(int c) {
       return getValueAt(0, c).getClass();
    }

    public boolean isCellEditable(int row, int col) {
        if (col < 2) {
           return false;
        } else {
           return true;
        }
    }

    public void setValueAt(Object value, int row, int col) {
        data[row][col] = value;
        fireTableCellUpdated(row, col);
    }

    }    

Answer 1

您应该避免使用object.getClass()来返回列的类类型。如果该值恰好是数据集中唯一的 null 值，会发生什么？

相反，您应该传回实际的列类...(注意如果没有您的实际数据，我不知道应该传递哪些值，所以这只是一个示例...)

public Class getColumnClass(int c) {
    return c < 2 ? String.class : Boolean.class;
}

已更新

要使 JTable 显示 JCheckBox，表模型必须从模型 getColumnClass 方法返回 Boolean。 ..这是最简单的解决方案，不过，您可以简单地为特定列提供自定义单元格渲染器。

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableModel;

public class TestTable11 {

    public static void main(String[] args) {
        new TestTable11();
    }

    public TestTable11() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException ex) {
                } catch (InstantiationException ex) {
                } catch (IllegalAccessException ex) {
                } catch (UnsupportedLookAndFeelException ex) {
                }

                TableModel model = new SimpleTableModel();

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new JScrollPane(new JTable(model)));
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class SimpleTableModel extends AbstractTableModel {

        private List<Object[]> rows;

        public SimpleTableModel() {
            rows = new ArrayList<>(5);
            rows.add(new Object[]{"Test1", "Test2", false});
            rows.add(new Object[]{"Test3", "Test4", false});
            rows.add(new Object[]{"Test5", "Test6", false});
            rows.add(new Object[]{"Test7", "Test8", false});
            rows.add(new Object[]{"Test9", "Test10", false});
            rows.add(new Object[]{"Test11", "Test11", false});
        }

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

        @Override
        public int getColumnCount() {
            return 3;
        }

        @Override
        public Object getValueAt(int rowIndex, int columnIndex) {
            return rows.get(rowIndex)[columnIndex];
        }

        @Override
        public boolean isCellEditable(int rowIndex, int columnIndex) {
            return columnIndex == 2;
        }

        @Override
        public Class<?> getColumnClass(int columnIndex) {
            return columnIndex < 2 ? String.class : Boolean.class;
        }

        @Override
        public void setValueAt(Object aValue, int rowIndex, int columnIndex) {
            if (columnIndex == 2 && aValue instanceof Boolean) {
                rows.get(rowIndex)[columnIndex] = aValue;
            }
        }        
    }    
}