将列添加到现有表模型

Question

我有一个班级;

public class A extends AbstractTableModel
{
 ...
}

使用ResultSetMetaData我构建TableModel以匹配数据库中的结果集。

public class B extends JPanel
{
 ...
}

在 B类中，我扩展了JPanel并添加了 A类来显示我的表格。 我希望能够根据条件向表模型添加新列。我尝试使用Google搜索，但大多数示例均基于DefaultTableModel而不是AbstractTableModel。

有谁知道如何实现这个目标？

Answer 1

例如

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

public class TableColumnHider {

    private JTable table;
    private TableColumnModel tcm;
    private Map hiddenColumns;

    public TableColumnHider(JTable table) {
        this.table = table;
        tcm = table.getColumnModel();
        hiddenColumns = new HashMap();
    }

    public void hide(String columnName) {
        int index = tcm.getColumnIndex(columnName);
        TableColumn column = tcm.getColumn(index);
        hiddenColumns.put(columnName, column);
        hiddenColumns.put(":" + columnName, new Integer(index));
        tcm.removeColumn(column);
    }

    public void show(String columnName) {
        Object o = hiddenColumns.remove(columnName);
        if (o == null) {
            return;
        }
        tcm.addColumn((TableColumn) o);
        o = hiddenColumns.remove(":" + columnName);
        if (o == null) {
            return;
        }
        int column = ((Integer) o).intValue();
        int lastColumn = tcm.getColumnCount() - 1;
        if (column < lastColumn) {
            tcm.moveColumn(lastColumn, column);
        }
    }

    public static void main(String[] args) {
        String[] columnNames = {"Name", "Size", "Type", "Date Modified", "Permissions"};
        String[][] data = {
            {"bin", "2", "dir", "Jun 9", "drwxr-xr-x"},
            {"boot", "3", "dir", "Jun 9", "drwxr-xr-x"},
            {"dev", "6", "dir", "Jul 12", "drwxr-xr-x"},
            {"etc", "34", "dir", "Jul 12", "drwxr-xr-x"},};
        JTable table = new JTable(data, columnNames);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        JScrollPane scrollPane = new JScrollPane(table);
        final TableColumnHider hider = new TableColumnHider(table);
        JPanel checkBoxes = new JPanel();
        for (int i = 0; i < columnNames.length; i++) {
            JCheckBox checkBox = new JCheckBox(columnNames[i]);
            checkBox.setSelected(true);
            checkBox.addActionListener(new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent evt) {
                    JCheckBox cb = (JCheckBox) evt.getSource();
                    String columnName = cb.getText();

                    if (cb.isSelected()) {
                        hider.show(columnName);
                    } else {
                        hider.hide(columnName);
                    }
                }
            });
            checkBoxes.add(checkBox);
        }
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(scrollPane);
        frame.getContentPane().add(checkBoxes, BorderLayout.SOUTH);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}

Answer 2

只是为了好玩，这里是@ mKorbel的TableColumnHider的通用版本。

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

/** @see https://stackoverflow.com/questions/6796673 */
public class TableColumnHider {

    private JTable table;
    private TableColumnModel tcm;
    private Map<String, IndexedColumn> hidden =
        new HashMap<String, IndexedColumn>();

    public TableColumnHider(JTable table) {
        this.table = table;
        this.tcm = table.getColumnModel();
    }

    public void hide(String columnName) {
        int index = tcm.getColumnIndex(columnName);
        TableColumn column = tcm.getColumn(index);
        IndexedColumn ic = new IndexedColumn(index, column);
        if (hidden.put(columnName, ic) != null) {
            throw new IllegalArgumentException("Duplicate column name.");
        }
        tcm.removeColumn(column);
    }

    public void show(String columnName) {
        IndexedColumn ic = hidden.remove(columnName);
        if (ic != null) {
            tcm.addColumn(ic.column);
            int lastColumn = tcm.getColumnCount() - 1;
            if (ic.index < lastColumn) {
                tcm.moveColumn(lastColumn, ic.index);
            }
        }
    }

    private static class IndexedColumn {

        private Integer index;
        private TableColumn column;

        public IndexedColumn(Integer index, TableColumn column) {
            this.index = index;
            this.column = column;
        }
    }

    public static void main(String[] args) {
        String[] columnNames = {
            "Name", "Size", "Type", "Date Modified", "Permissions"
        };
        String[][] data = {
            {"bin", "2", "dir", "Jun 9", "drwxr-xr-x"},
            {"boot", "3", "dir", "Jun 9", "drwxr-xr-x"},
            {"dev", "6", "dir", "Jul 12", "drwxr-xr-x"},
            {"etc", "34", "dir", "Jul 12", "drwxr-xr-x"}
        };
        JTable table = new JTable(data, columnNames);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        JScrollPane scrollPane = new JScrollPane(table);
        final TableColumnHider hider = new TableColumnHider(table);
        JPanel checkBoxes = new JPanel();
        for (int i = 0; i < columnNames.length; i++) {
            JCheckBox checkBox = new JCheckBox(columnNames[i]);
            checkBox.setSelected(true);
            checkBox.addActionListener(new ActionListener() {

                @Override
                public void actionPerformed(ActionEvent evt) {
                    JCheckBox cb = (JCheckBox) evt.getSource();
                    String columnName = cb.getText();

                    if (cb.isSelected()) {
                        hider.show(columnName);
                    } else {
                        hider.hide(columnName);
                    }
                }
            });
            checkBoxes.add(checkBox);
        }
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(scrollPane);
        frame.getContentPane().add(checkBoxes, BorderLayout.SOUTH);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}

Answer 3

只需扩展DefaultTableModel，然后您就可以访问其所有方法。 DefaultTableModel还扩展了AbstractTableModel，因此在代码的其他部分对AbstractTableModel的引用不会破坏。

Answer 4

肯定DefaultTableModel更方便，但AbstractTableModel提供了更大的灵活性和更少的开销。有一个示例here显示包含List<Value>的模型，其中Value是POJO。可以找到更多示例here。

Answer 5

请注意mKorbel和trashgod中的代码示例不保留列的原始顺序。只是尝试按顺序隐藏所有列，然后再次以相同的顺序显示它们（Name-＆gt; Size-＆gt; Type-＆gt; Date Modified-＆gt; Permissions），您将看到原始订单丢失。

如果您需要在再次显示列时保留列的原始顺序，请查看Stephen Kelvin's solution。

不幸的是，“视图”和“模型”之间的混淆在JTable API中很普遍。即使是方法名称也会产生误导。对于某些启示，请参阅相关讨论here。

Answer 6

我已将DefaultTableModel的addColumn方法改编为自定义AbstractTableModel，如下所示。假设列标识符（标题）和模型数据（localCache）都是ArrayLists - 模型数据是ArrayList的ArrayList。

public void addColumn(String columnName, List columnData) {
    headers.add(columnName);
    colCount = headers.size();
    if (columnData != null) {
        for (int r = 0; r < localCache.size(); r++) {
            ((List)localCache.get(r)).add(columnData.get(r));
        }
    } else {
        System.out.println("Null columnData passed");
    }
    fireTableStructureChanged();
}