我一直在考虑解决这个错误。但不幸的是，我得到了最后的结论，我需要专业人士的帮助。
请复制，粘贴此代码以查看问题：
public class DateFormatDemo extends JFrame
{
private JTable dataSearchResultTable;
public DateFormatDemo()
{
JButton updateTable = new JButton("Update table");
updateTable.setMaximumSize(updateTable.getPreferredSize());
updateTable.addActionListener(new ActionListener()
{
@Override
public void actionPerformed(ActionEvent e)
{
updateMyTableModel();
}
});
JPanel panel = new JPanel(new GridLayout(2, 1, 5, 10));
panel.setPreferredSize(new Dimension(500, 300));
panel.add(new JScrollPane(initDataSearchResultTable()));
panel.add(updateTable);
super.getContentPane().add(panel);
super.pack();
super.setDefaultCloseOperation(EXIT_ON_CLOSE);
super.setVisible(true);
}
private JTable initDataSearchResultTable()
{
dataSearchResultTable = new JTable();
// dataSearchResultTable.setAutoCreateColumnsFromModel(false);
dataSearchResultTable.setSelectionBackground(new Color(0xaaaaff));
dataSearchResultTable.setFillsViewportHeight(true);
dataSearchResultTable.setRowSelectionAllowed(true);
dataSearchResultTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
dataSearchResultTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
return dataSearchResultTable;
}
void updateMyTableModel()
{
TableModel tableModel = dataSearchResultTable.getModel();
TableColumnModel columnModel = dataSearchResultTable.getColumnModel();
if (tableModel instanceof MyTableModel) {
((MyTableModel) tableModel).updateModel();
this.initColumnWidths(tableModel, columnModel);
} else {
tableModel = new MyTableModel();
dataSearchResultTable.setModel(tableModel);
this.makeColumnsNotResizable(columnModel);
this.initColumnWidths(tableModel, columnModel);
}
}
private void makeColumnsNotResizable(TableColumnModel columnModel)
{
for (int i = 0; i < columnModel.getColumnCount(); i++) {
if (i == 0 || i == 1) {
columnModel.getColumn(i).setResizable(false);
}
}
}
private void initColumnWidths(TableModel tableModel, TableColumnModel columnModel)
{
TableColumn column = null;
Component comp = null;
int cellWidth = 0;
int headerWidth = 0;
TableCellRenderer headerRenderer = dataSearchResultTable.getTableHeader().getDefaultRenderer();
for (int i = 0; i < columnModel.getColumnCount(); i++) {
column = columnModel.getColumn(i);
comp = headerRenderer.getTableCellRendererComponent(null, column.getHeaderValue(), false, false, -1, 0);
headerWidth = comp.getPreferredSize().width;
Class<?> columnClass = tableModel.getColumnClass(i);
for (int j = 0; j < tableModel.getRowCount(); j++) {
comp = dataSearchResultTable.getDefaultRenderer(columnClass).getTableCellRendererComponent(
dataSearchResultTable, tableModel.getValueAt(j, i), false, false, j, i);
int width = comp.getPreferredSize().width;
// we cache width of first row. And compare widths of next
// rows with width of first.
// If some row has greater width it becomes width of whole
// row(unless header has greater width)
if (cellWidth < width || j == 0) {
cellWidth = width;
}
}
System.out
.println("columnClass=" + columnClass + ",headerWidth=" + headerWidth + ",cellWidth=" + cellWidth);
if (headerWidth > cellWidth) {
TableCellRenderer centeredRenderer = dataSearchResultTable.getDefaultRenderer(columnClass);
if (centeredRenderer instanceof DefaultTableCellRenderer) {
((DefaultTableCellRenderer) centeredRenderer).setHorizontalAlignment(SwingConstants.CENTER);
column.setCellRenderer(centeredRenderer);
column.setPreferredWidth(headerWidth);
}
} else {
column.setPreferredWidth(cellWidth + 5);
}
}
}
class MyTableModel extends AbstractTableModel
{
private String[] columnNames = { "First Name", "Last Name", "Timestamp", "Number", "Vegetarian" };
private Object[][] data = new Object[5][];
void updateModel()
{
data = new Object[][] {
{ "Vova", "KipokKipokKipokKipok", "2013-04-12 11:20:41", new Integer(5), new Boolean(true) },
{ "Olia", "Duo", "2010-01-11 11:11:41", new Integer(3), new Boolean(false) },
{ "Oksana", "Stack", "2012-04-12 11:20:41", new Integer(2), new Boolean(false) },
{ "Petro", "White", "2010-04-12 11:20:21", new Integer(20), new Boolean(true) },
{ "Ivan", "Brown", "2011-04-11 11:20:41", new Integer(10), new Boolean(true) } };
fireTableDataChanged();
}
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)
{
if (data.length > 0 && data[0] != null) {
return data[row][col];
}
return null;
}
/*
* JTable uses this method to determine the default renderer/ editor for
* each cell. If we didn't implement this method, then the last column
* would contain text ("true"/"false"), rather than a check box.
*/
public Class getColumnClass(int c)
{
Object valueAt = getValueAt(0, c);
return valueAt == null ? Object.class : valueAt.getClass();
}
/*
* Don't need to implement this method unless your table's editable.
*/
public boolean isCellEditable(int row, int col)
{
// Note that the data/cell address is constant,
// no matter where the cell appears onscreen.
if (col < 2) {
return false;
} else {
return true;
}
}
/*
* Don't need to implement this method unless your table's data can
* change.
*/
public void setValueAt(Object value, int row, int col)
{
if (data.length > 0 && data[0] != null) {
data[row][col] = value;
fireTableCellUpdated(row, col);
}
}
}
public static void main(String[] args) throws ParseException
{
new DateFormatDemo();
}
}
现在请在名为“更新表”的大按钮上单击两次。如您所见，列应该显示复选框，因为它保持布尔值不会这样做，而是显示字符串true或false。
此代码模拟我的真实工作流程。 那么，如何更新tablemodel以使用带有checkbozes的布尔列。
谢谢！
答案 0 :(得分：3)
将此视为简单的起点
import java.awt.*;
import java.util.Random;
import java.util.Vector;
import javax.swing.*;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableCellRenderer;
public class Forum implements ListSelectionListener {
private JFrame frame = new JFrame("Frame");
private JPanel fatherCenter = new JPanel();
private JScrollPane tableScroll = new JScrollPane();
private MyTableModel tableModel;
private JTable dialogTable;
private ListSelectionModel lsDialog;
private Color clr;
private Color clr1;
private void addData() {
Runnable doRun1 = new Runnable() {
@Override
public void run() {
tableModel.resetTable();
Vector<String> tbl = new Vector<String>();
Vector<Object> tbl1 = new Vector<Object>();
Random rnd = new Random();
tbl.add("Integer");
tbl.add("Double");
tbl.add("Boolean");
tbl.add("Boolean");
tbl.add("String");
tableModel.setColumnNames(tbl);
for (int row = 0; row < 30; row++) {
tbl1 = null;
tbl1 = new Vector<Object>();
tbl1.addElement(row + 1);
tbl1.addElement(rnd.nextInt(25) + 3.14);
tbl1.addElement((row % 3 == 0) ? false : true);
tbl1.addElement((row % 5 == 0) ? false : true);
if (row % 7 == 0) {
tbl1.add(("Canc"));
} else if (row % 6 == 0) {
tbl1.add(("Del"));
} else {
tbl1.add(("New"));
}
tableModel.addRow(tbl1);
}
addTableListener();
}
};
SwingUtilities.invokeLater(doRun1);
}
private void addTableListener() {
tableModel.addTableModelListener(new TableModelListener() {
@Override
public void tableChanged(TableModelEvent tme) {
if (tme.getType() == TableModelEvent.UPDATE) {
System.out.println("");
System.out.println("Cell " + tme.getFirstRow() + ", "
+ tme.getColumn() + " changed. The new value: "
+ tableModel.getValueAt(tme.getFirstRow(),
tme.getColumn()));
}
}
});
}
@Override
public void valueChanged(ListSelectionEvent le) {
int row = dialogTable.getSelectedRow();
int col = dialogTable.getSelectedColumn();
String str = "Selected Row(s): ";
int[] rows = dialogTable.getSelectedRows();
for (int i = 0; i < rows.length; i++) {
str += rows[i] + " ";
}
str += "Selected Column(s): ";
int[] cols = dialogTable.getSelectedColumns();
for (int i = 0; i < cols.length; i++) {
str += cols[i] + " ";
}
str += "Selected Cell: " + dialogTable.getSelectedRow() + ", " + dialogTable.getSelectedColumn();
System.out.println(str);
Object value = dialogTable.getValueAt(row, col);
System.out.println(String.valueOf(value));
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
Forum osFrame = new Forum();
}
});
}
public Forum() {
tableModel = new MyTableModel();
dialogTable = new JTable(tableModel) {
private static final long serialVersionUID = 1L;
@Override
public Component prepareRenderer(TableCellRenderer renderer, int row, int column) {
Component comp = super.prepareRenderer(renderer, row, column);
JComponent jc = (JComponent) comp;//for Custom JComponent
if (!isRowSelected(row)) {
int modelRow = convertRowIndexToModel(row);
boolean type = (Boolean) getModel().getValueAt(modelRow, 2);
boolean type1 = (Boolean) getModel().getValueAt(modelRow, 3);
comp.setForeground(Color.black);
if ((type) && (!type1)) {
comp.setBackground(clr1);
} else if ((!type) && (type1)) {
comp.setBackground(Color.orange);
} else if ((!type) || (!type1)) {
comp.setBackground(Color.red);
} else {
comp.setBackground(row % 2 == 0 ? getBackground() : getBackground().darker());
}
dialogTable.convertRowIndexToView(0);
} else {
comp.setForeground(Color.blue);
}
if (!isCellEditable(row, column)) {
comp.setForeground(Color.red);
comp.setBackground(Color.magenta);
}
return comp;
}
};
tableScroll = new JScrollPane(dialogTable, ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED);
tableScroll.setBorder(null);
dialogTable.getTableHeader().setReorderingAllowed(false);
dialogTable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
lsDialog = dialogTable.getSelectionModel();
dialogTable.putClientProperty("terminateEditOnFocusLost", Boolean.TRUE);
dialogTable.setRowHeight(20);
dialogTable.setRowMargin(2);
dialogTable.setPreferredScrollableViewportSize(dialogTable.getPreferredSize());
ListSelectionModel rowSelMod = dialogTable.getSelectionModel();
//ListSelectionModel colSelMod = dialogTable.getColumnModel().getSelectionModel();
rowSelMod.addListSelectionListener(this);
//colSelMod.addListSelectionListener(this);
fatherCenter = new JPanel();
fatherCenter.setLayout(new BorderLayout(10, 10));
fatherCenter.add(tableScroll, BorderLayout.CENTER);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout(10, 10));
frame.add(fatherCenter);
frame.setPreferredSize(new Dimension(400, 660));
frame.pack();
frame.setLocation(150, 150);
frame.setVisible(true);
addData();
}
private class MyTableModel extends AbstractTableModel {
private static final long serialVersionUID = 1L;
private Vector<Vector<Object>> _data;
private Vector<String> _colNames;
private boolean[] _columnsVisible = {true, true, true, true, true};
public MyTableModel() {
_colNames = new Vector<String>();
_data = new Vector<Vector<Object>>();
}
public MyTableModel(Vector<String> colnames) {
_colNames = colnames;
_data = new Vector<Vector<Object>>();
}
public void resetTable() {
_colNames.removeAllElements();
_data.removeAllElements();
}
public void setColumnNames(Vector<String> colNames) {
_colNames = colNames;
fireTableStructureChanged();
}
public void addRow(Vector<Object> data) {
_data.add(data);
fireTableRowsInserted(_data.size() - 1, _data.size() - 1);
}
public void removeRowAt(int row) {
_data.removeElementAt(row);
fireTableRowsDeleted(row - 1, _data.size() - 1);
}
@Override
public int getColumnCount() {
return _colNames.size();
}
@Override
public Class<?> getColumnClass(int colNum) {
switch (colNum) {
case 0:
return Integer.class;
case 1:
return Double.class;
case 2:
return Boolean.class;
case 3:
return Boolean.class;
default:
return String.class;
}
}
@Override
public boolean isCellEditable(int row, int colNum) {
switch (colNum) {
case 2:
return false;
default:
return true;
}
}
@Override
public String getColumnName(int colNum) {
return _colNames.get(colNum);
}
@Override
public int getRowCount() {
return _data.size();
}
@Override
public Object getValueAt(int row, int col) {
Vector<Object> value = _data.get(row);
return value.get(col);
}
@Override
public void setValueAt(Object newVal, int row, int col) {
Vector<Object> aRow = _data.elementAt(row);
aRow.remove(col);
aRow.insertElementAt(newVal, col);
fireTableCellUpdated(row, col);
}
public void setColumnVisible(int index, boolean visible) {
_columnsVisible[index] = visible;
fireTableStructureChanged();
}
}
}
答案 1 :(得分：1)
您在getColumnClass方法中遇到的问题也会返回Object，因为您还会获得String列。
您可以通过下一种方式确定该方法：
@Override
public Class<?> getColumnClass(int arg0) {
return longValues[arg0].getClass();
}
或以其他方式返回列的类。但是你必须在修改你的模型的同时确定这个类。