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[英]JTable, TableModel and TableColumnModel - Weird thing going on
[英]How to remove a JTable column from both TableModel and TableColumnModel with setAutoCreateColumnsFromModel(false)?
最后看我的SSCCE代碼。 我想要實現的是:
setAutoCreateColumnsFromModel(false)
來避免在數據/表模型添加或刪除列時重新創建列模型 大按鈕在末尾添加一個新列。 每個新列都獲得一個唯一標識符。
標題有一個右鍵菜單HeaderMenu
來刪除列。 計時器調用table.tableModel.addRow()
在頂部插入一個新行。 每列的數據由類Column
生成。 在此演示中,值只是一個帶有列標識符的行計數器。
在實際表中(不是這個演示)
Column
的子類,並生成有意義的數據 此演示演示了刪除列的問題,這些列會生成如下錯誤:
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 2 >= 2
at java.util.Vector.elementAt(Vector.java:477)
at javax.swing.table.DefaultTableModel.getValueAt(DefaultTableModel.java:649)
at javax.swing.JTable.getValueAt(JTable.java:2720)
at javax.swing.JTable.prepareRenderer(JTable.java:5712)
at javax.swing.plaf.basic.BasicTableUI.paintCell(BasicTableUI.java:2114)
...
請告知如何解決它。 這是整個代碼:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.Vector;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;
@SuppressWarnings("serial")
public class TableDemo extends JTable {
private static class Column {
private int rowsCounter = 0;
private final String identifier;
public Column(String identifier) {
this.identifier = identifier;
}
private String nextCellValue() {
return (rowsCounter++) + ", id: " + identifier;
}
}
private static class MyTableModel extends DefaultTableModel {
private final List<Column> columns = new ArrayList<>();
private int nextColumnIdentifier = 0;
private void addRow() {
Object[] row = columns.stream().map(Column::nextCellValue).toArray();
insertRow(0, row);
}
private TableColumn addColumn() {
String identifier = String.valueOf(nextColumnIdentifier++);
columns.add(new Column(identifier));
addColumn(identifier);
TableColumn tc = new TableColumn();
tc.setIdentifier(identifier);
tc.setHeaderValue(identifier);
tc.setModelIndex(columns.size() - 1);
return tc;
}
private void removeColumn(int idx) {
columns.remove(idx);
columnIdentifiers.remove(idx);
for (Object row : dataVector) {
((Vector<?>) row).remove(idx);
}
fireTableStructureChanged();
}
}
private static class HeaderMenu extends JPopupMenu {
private int columnViewIndex;
private HeaderMenu(final TableDemo table) {
JMenuItem item = new JMenuItem("Delete column");
item.addActionListener(e -> table.deleteColumn(columnViewIndex));
add(item);
final MouseAdapter ma = new MouseAdapter() {
boolean dragged = false;
@Override
public void mouseReleased(MouseEvent e) {
if (!dragged && e.getButton() == MouseEvent.BUTTON3) {
final Point p = e.getPoint();
SwingUtilities.invokeLater(() -> {
columnViewIndex = table.columnAtPoint(p);
show(e.getComponent(), p.x, p.y);
});
}
dragged = false;
}
@Override
public void mouseDragged(MouseEvent e) {
dragged = true;
}
};
table.getTableHeader().addMouseListener(ma);
table.getTableHeader().addMouseMotionListener(ma);
}
}
private MyTableModel tableModel = new MyTableModel();
private TableDemo() {
new HeaderMenu(this);
setModel(tableModel);
setAutoCreateColumnsFromModel(false);
setDefaultEditor(Object.class, null);
}
private void addColumn() {
TableColumn tc = tableModel.addColumn();
addColumn(tc);
}
void deleteColumn(int idxView) {
TableColumn tc = getColumnModel().getColumn(idxView);
tableModel.removeColumn(tc.getModelIndex());
removeColumn(tc);
}
private static void buildAndShowGui() {
TableDemo table = new TableDemo();
table.setPreferredScrollableViewportSize(new Dimension(800, 300));
table.setFillsViewportHeight(true);
JScrollPane tableScrollPane = new JScrollPane(table);
JButton buttonAdd = new JButton("Add column");
buttonAdd.addActionListener(e -> table.addColumn());
int gaps = 10;
JPanel panel = new JPanel(new BorderLayout(gaps, gaps));
panel.setBorder(BorderFactory.createEmptyBorder(gaps, gaps, gaps, gaps));
panel.add(buttonAdd, BorderLayout.NORTH);
panel.add(tableScrollPane, BorderLayout.CENTER);
JFrame frame = new JFrame(table.getClass().getSimpleName());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(panel);
frame.pack();
frame.setVisible(true);
new Timer().schedule(new TimerTask() {
@Override
public void run() {
SwingUtilities.invokeLater(() -> table.tableModel.addRow());
}
}, 500, 100);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> buildAndShowGui());
}
}
問題是在從表/數據模型中的某些modelIndex
中刪除列之后,列模型中某些列的TableColumn#getModelIndex()
可能會移位1.這是一個示例,假設表有3個列和下面的代碼生成0 1 2
:
for (int i = 0; i < getColumnModel().getColumnCount(); i++) {
System.out.print(getColumnModel().getColumn(i).getModelIndex() + " ");
}
然后從數據模型和列模型中刪除列1
后,此代碼的輸出變為: 0 2
。 因此,當訪問數據模型中不存在的第2
列時, JTable
會生成ArrayIndexOutOfBoundsException
。 這就是刪除最后一列沒有產生錯誤的原因。
解決方案是移動已刪除列右側列的modelIndex
。 這可以使用自定義TableColumnModel完成:
private static class MyColumnsModel extends DefaultTableColumnModel {
private TableColumn deleteColumn(int idxView) {
if (selectionModel != null) {
selectionModel.removeIndexInterval(idxView, idxView);
}
TableColumn tc = tableColumns.remove(idxView);
tc.removePropertyChangeListener(this);
for (TableColumn tableColumn : tableColumns) {
if (tableColumn.getModelIndex() > tc.getModelIndex()) {
tableColumn.setModelIndex(tableColumn.getModelIndex() - 1);
}
}
return tc;
}
}
並使用表的添加/刪除方法如下:
private void addColumn() {
TableColumn tc = tableModel.addColumn();
addColumn(tc); // equal to columnsModel.addColumn(tc);
}
private void deleteColumn(int idxView) {
TableColumn tc = columnsModel.deleteColumn(idxView);
tableModel.removeColumn(tc.getModelIndex());
}
這是整個固定代碼:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;
import java.util.Vector;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.DefaultTableColumnModel;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableColumn;
@SuppressWarnings("serial")
public class TableDemo extends JTable {
private static class Column {
private int rowsCounter = 0;
private final String identifier;
public Column(String identifier) {
this.identifier = identifier;
}
private String nextCellValue() {
return (rowsCounter++) + ", id: " + identifier;
}
}
private static class MyTableModel extends DefaultTableModel {
private final List<Column> columns = new ArrayList<>();
private int nextColumnIdentifier = 0;
private void addRow() {
Object[] row = columns.stream().map(Column::nextCellValue).toArray();
insertRow(0, row);
}
private TableColumn addColumn() {
String identifier = String.valueOf(nextColumnIdentifier++);
columns.add(new Column(identifier));
addColumn(identifier);
TableColumn tc = new TableColumn();
tc.setIdentifier(identifier);
tc.setHeaderValue(identifier);
tc.setModelIndex(columns.size() - 1);
return tc;
}
private void removeColumn(int idx) {
columns.remove(idx);
columnIdentifiers.remove(idx);
for (Object row : dataVector) {
((Vector<?>) row).remove(idx);
}
fireTableStructureChanged();
}
}
private static class MyColumnsModel extends DefaultTableColumnModel {
private TableColumn deleteColumn(int idxView) {
if (selectionModel != null) {
selectionModel.removeIndexInterval(idxView, idxView);
}
TableColumn tc = tableColumns.remove(idxView);
tc.removePropertyChangeListener(this);
for (TableColumn tableColumn : tableColumns) {
if (tableColumn.getModelIndex() > tc.getModelIndex()) {
tableColumn.setModelIndex(tableColumn.getModelIndex() - 1);
}
}
return tc;
}
}
private static class HeaderMenu extends JPopupMenu {
private int columnViewIndex;
private HeaderMenu(final TableDemo table) {
JMenuItem item = new JMenuItem("Delete column");
item.addActionListener(e -> table.deleteColumn(columnViewIndex));
add(item);
final MouseAdapter ma = new MouseAdapter() {
boolean dragged = false;
@Override
public void mouseReleased(MouseEvent e) {
if (!dragged && e.getButton() == MouseEvent.BUTTON3) {
final Point p = e.getPoint();
SwingUtilities.invokeLater(() -> {
columnViewIndex = table.columnAtPoint(p);
show(e.getComponent(), p.x, p.y);
});
}
dragged = false;
}
@Override
public void mouseDragged(MouseEvent e) {
dragged = true;
}
};
table.getTableHeader().addMouseListener(ma);
table.getTableHeader().addMouseMotionListener(ma);
}
}
private MyTableModel tableModel = new MyTableModel();
private MyColumnsModel columnsModel = new MyColumnsModel();
private TableDemo() {
new HeaderMenu(this);
setModel(tableModel);
setColumnModel(columnsModel);
setAutoCreateColumnsFromModel(false);
setDefaultEditor(Object.class, null);
}
private void addColumn() {
TableColumn tc = tableModel.addColumn();
addColumn(tc); // equal to columnsModel.addColumn(tc);
}
private void deleteColumn(int idxView) {
TableColumn tc = columnsModel.deleteColumn(idxView);
tableModel.removeColumn(tc.getModelIndex());
}
private static void buildAndShowGui() {
TableDemo table = new TableDemo();
table.setPreferredScrollableViewportSize(new Dimension(800, 300));
table.setFillsViewportHeight(true);
JScrollPane tableScrollPane = new JScrollPane(table);
JButton buttonAdd = new JButton("Add column");
buttonAdd.addActionListener(e -> table.addColumn());
int gaps = 10;
JPanel panel = new JPanel(new BorderLayout(gaps, gaps));
panel.setBorder(BorderFactory.createEmptyBorder(gaps, gaps, gaps, gaps));
panel.add(buttonAdd, BorderLayout.NORTH);
panel.add(tableScrollPane, BorderLayout.CENTER);
JFrame frame = new JFrame(table.getClass().getSimpleName());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(panel);
frame.pack();
frame.setVisible(true);
new Timer().schedule(new TimerTask() {
@Override
public void run() {
SwingUtilities.invokeLater(() -> table.tableModel.addRow());
}
}, 500, 100);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> buildAndShowGui());
}
}
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