動態將數據添加到AbstractTableModel的Extended類

Question

我有一些從數據庫加載的數據並作為公共靜態列表存儲在另一個類中，我無法訪問MyTableModel類中的數據來存儲並在jtable中查看它們……還有許多其他方式可以用我的數據填寫表格，但他們不給我列檢查框……我該怎么辦？

    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

您應該避免使用object.getClass()返回列的類類型。 如果該值恰好是數據集中唯一的null值，會發生什么情況？

相反，您應該傳遞實際的列類...（nb，如果沒有實際數據，我不知道應該傳遞什么值，所以這只是一個示例...）

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

更新

為了讓JTable顯示JCheckBox ，表模型必須從模型getColumnClass方法返回Boolean 。這是最簡單的解決方案，然后，您可以簡單地為特定列提供自定義單元格渲染器。

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;
            }
        }        
    }    
}