Develop Reference

Copying (some columns of) a JTable to a new JTable

I have a JTable displayed in a frame. This table must remain unmodified for
later processing. At some point I want to show a column reduced version of this
table in a dialog. So I make a copy of the original table in creating a new
TableModel and TableColumnModel, thereby skipping the columns not needed.
Everything is fine until the dialog is set to visible. Then I run into an
endless error loop, starting with an "ArrayIndexOutOfBoundsException: 3 >= 2".
If 3 is the index to a table row, then it's indeed too large.
As the reduced table has only two columns, a column index of 2 would already exceed. Checking the columns with
getColumnCount() shows that the values are ok.
I suspect my copyTable method to be the culprit, but have no idea where the 3
index is coming from.
Instead of filling the rows of the table's model one by one, I succeeded using DefaultTableModel.addColumn(Object columnName, Object[] columnData) as suggested here. Then, however, I lose the columns' width information. Hence I would still like to know my fault in the current code.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
public class CopyTable extends JFrame {
public static final long serialVersionUID = 100L;
public CopyTable() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
JTable table= createTable();
JScrollPane scroll= new JScrollPane(table);
add(scroll, BorderLayout.CENTER);
JButton b= new JButton("Show dialog");
b.addActionListener(e -> createAndShowDialog(table));
add(b, BorderLayout.SOUTH);
setSize(table.getColumnModel().getTotalColumnWidth()+11, 240);
setVisible(true);
}
static public void main(String args[]) {
EventQueue.invokeLater(CopyTable::new);
}
// #param columns Indices of columns to be copied into the new table.
public JTable copyTable(JTable table, int... columns) {
DefaultTableModel tblModel= new DefaultTableModel(0, columns.length);
DefaultTableModel oldModel= (DefaultTableModel)table.getModel();
Object[] row= new Object[columns.length];
int iRow= 0;
while (iRow<oldModel.getRowCount()) {
for (int i=0; i<columns.length; i++) {
row[i]= oldModel.getValueAt(iRow, columns[i]);
}
tblModel.addRow(row);
iRow++;
}
DefaultTableColumnModel colModel= new DefaultTableColumnModel();
DefaultTableColumnModel oldColModel=
(DefaultTableColumnModel)table.getColumnModel();
for (int i=0; i<columns.length; i++) {
colModel.addColumn(oldColModel.getColumn(columns[i]));
/* Creating a new column didn't help.
TableColumn tc= new TableColumn();
tc= oldColModel.getColumn(columns[i]);
colModel.addColumn(tc);
*/
}
return new JTable(tblModel, colModel);
}
private void createAndShowDialog(JTable table) {
JTable tbl = copyTable(table, 0, 3); // Copy only columns 0 and 3.
JOptionPane.showMessageDialog(this, ""+tbl.getModel().getRowCount()+", "+
tbl.getModel().getColumnCount()+", "+
tbl.getColumnModel().getColumnCount(),
"Checking row/column count",
JOptionPane.INFORMATION_MESSAGE);
JDialog dlg= new JDialog(this, "Reduced table", true);
dlg.setLocationRelativeTo(this);
JScrollPane scroll = new JScrollPane(tbl);
dlg.add(scroll, BorderLayout.CENTER);
dlg.pack();
dlg.setVisible(true);
}
private JTable createTable() {
String headers[] = {"Fruit", "Colour", "Count", "Price"};
Object data[][] = {
{"Apple", "Green", 6, .3},
{"Banana", "Yellow", 3, .4},
{"Cherry", "Red", 10, 1.1}
};
DefaultTableModel model = new DefaultTableModel(data, headers) {
public Class<?> getColumnClass(int column) {
Class<?> returnValue;
if (column>=0 && column<getColumnCount() && getValueAt(0,column)!=null)
returnValue= getValueAt(0, column).getClass();
else
returnValue= Object.class;
return returnValue;
}
};
JTable tbl= new JTable(model);
TableColumnModel tcm= tbl.getColumnModel();
int[] width= new int[] {60, 50, 40, 40};
for (int i=0; i<headers.length; i++) {
tcm.getColumn(i).setPreferredWidth(width[i]);
tcm.getColumn(i).setWidth(width[i]);
}
return tbl;
}
}
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 3 >= 2
at java.base/java.util.Vector.elementAt(Vector.java:466)
at java.desktop/javax.swing.table.DefaultTableModel.getValueAt(DefaultTableModel.java:661)
at java.desktop/javax.swing.JTable.getValueAt(JTable.java:2763)
at java.desktop/javax.swing.JTable.prepareRenderer(JTable.java:5780)
at java.desktop/javax.swing.plaf.basic.BasicTableUI.paintCell(BasicTableUI.java:2207)
at java.desktop/javax.swing.plaf.basic.BasicTableUI.paintCells(BasicTableUI.java:2109)
at java.desktop/javax.swing.plaf.basic.BasicTableUI.paint(BasicTableUI.java:1905)
at java.desktop/javax.swing.plaf.ComponentUI.update(ComponentUI.java:161)
at java.desktop/javax.swing.JComponent.paintComponent(JComponent.java:852)
java 18

There is no need to copy the TableModel (they are shareable by design) - all you need is a new TableColumnModel containing clones of the original: note that the relevant coordinate system is the model index.
Example:
TableColumnModel sourceColumnModel = sourceTable.getColumnModel();
DefaultTableColumnModel reducedColumnModel = new DefaultTableColumnModel();
for (int i = 0; i < sourceColumnModel.getColumnCount(); i++) {
TableColumn sourceColumn = sourceColumnModel.getColumn(i);
int modelIndex = sourceColumn.getModelIndex();
if (modelIndex % 2 == 0) { // replace with your condition
TableColumn column = new TableColumn(modelIndex, sourceColumn.getPreferredWidth());
column.setHeaderValue(sourceColumn.getHeaderValue());
reducedColumnModel.addColumn(column);
}
}
JTable reducedTable = new JTable(sourceTable.getModel(), reducedColumnModel);

#g00se
Your solution works. Thank you. The only drawback is that removing columns from the TableColumnModel doesn't remove them from the TableModel. So I added the following to your code
int icnt= oldModel.getRowCount();
for (int j=0; j<icnt; j++) {
Vector<?> vec= (Vector<?>)data.get(j);
for (int i=columns.length-1; i>=0; i--) {
vec.removeElementAt(columns[i]);
}
data.setElementAt(vec, j);
}
((DefaultTableModel)result.getModel()).setDataVector(data, headers);
return result;
But due to lack of Generics knowledge, I cannot make the code compile. Still an idea for that?
Just copying/creating a new model would avoid any removal. So I am still curious as for my original error.
Edit
----------------------------------------------------------
Generics:
Vector<Vector<Object>> data = ...
...
Vector<Object> vec= data.get(j);
----------------------------------------------------------
Finally I got my original version to work. colModel.addColumn(oldColModel.getColumn(columns[i])); passes only a reference of the column. But one has to create a new instance for each column in the new table.
// #param columns Indices of columns to be copied into the new table.
public JTable copyTable(JTable table, int... columns) {
DefaultTableModel oldModel= (DefaultTableModel)table.getModel();
DefaultTableModel tblModel= new DefaultTableModel(0, columns.length) {
public Class<?> getColumnClass(int column) {
Class<?> returnValue;
if (column>=0 && column<getColumnCount() && getValueAt(0,column)!=null)
returnValue= getValueAt(0, column).getClass();
else
returnValue= Object.class;
return returnValue;
}
};
Object[] row= new Object[columns.length];
int icnt= oldModel.getRowCount();
for (int i=0; i<icnt; i++) {
for (int j=0; j<columns.length; j++) {
row[j]= oldModel.getValueAt(i, columns[j]);
}
tblModel.addRow(row);
}
DefaultTableColumnModel oldColModel=
(DefaultTableColumnModel)table.getColumnModel();
DefaultTableColumnModel colModel= new DefaultTableColumnModel();
for (int i=0; i<columns.length; i++) {
// colModel.addColumn(oldColModel.getColumn(columns[i])); // Endless err loop
TableColumn tc= oldColModel.getColumn(columns[i]);
TableColumn tcNew= new TableColumn(i, tc.getPreferredWidth(),
tc.getCellRenderer(), tc.getCellEditor());
tcNew.setHeaderValue(tc.getHeaderValue());
colModel.addColumn(tcNew);
}
return new JTable(tblModel, colModel);
}
private void createAndShowDialog(JTable table) {
JTable tbl = copyTable(table, 0, 1, 3); // Copy only columns 0, 1 and 3.
JDialog dlg= new JDialog(this, "Reduced table", true);
JScrollPane scroll = new JScrollPane(tbl);
scroll.setPreferredSize(
new Dimension(tbl.getColumnModel().getTotalColumnWidth(), 80));
dlg.add(scroll, BorderLayout.CENTER);
dlg.pack();
dlg.setLocationRelativeTo(this);
dlg.setVisible(true);
}

I can't say I know quite why you get that exception, but this is a possible problem-free alternative, involving cloning the table then removing unwanted columns. This is based on the intuitive ascending ordering of required columns. Obviously the logic could be made easier by passing an array of columns to be removed rather than retained.
// #param columns Indices of columns to be copied into the new table.
public JTable copyTable(JTable table, int... columns) {
DefaultTableModel oldModel = (DefaultTableModel) table.getModel();
#SuppressWarnings("unchecked")
Vector<? extends Vector> data = (Vector<? extends Vector>) oldModel.getDataVector().clone();
Vector<Object> headers = new Vector<>();
TableColumnModel cmSource = table.getColumnModel();
for (int i = 0; i < table.getColumnModel().getColumnCount(); i++) {
headers.add(cmSource.getColumn(i).getIdentifier());
}
JTable result = new JTable(data, headers);
TableColumnModel cmTarget = result.getColumnModel();
Set<Integer> columnsToCopy = new HashSet<>();
for (int i = columns.length; --i >= 0;) {
columnsToCopy.add(columns[i]);
}
for (int i = cmTarget.getColumnCount(); --i >= 0;) {
if (!columnsToCopy.contains(i)) {
cmTarget.removeColumn(cmTarget.getColumn(i));
}
}
return result;
}

JTable select and deselect not working

I have a problem with my JTable. Firstly I selected some entries in my table. However when I deselect some of them, the table could not understand it.
Example scenario: I select job1 and 2 for the testing after that I change my mind and de-select job2. But in the result I saw job1 job1 and job2 ( job 1 seen 2 times and even though I dis-select job 2 I saw them.) Or after selected all the jobs ( choose all button) I want to deselect all of them (Clear button) when I click clear all the table seems empty. It is good but somehow the background of the program still protect the all old selection. How can I solve this?
Try:
I created the row of my table by read csv file.
public class JobSelectionListPanel extends JPanel {
private static final long serialVersionUID = 5198916547962359735L;
private static JobSelectionListPanel INSTANCE = new JobSelectionListPanel();
public static JobSelectionListPanel getInstance() {
return INSTANCE;
}
private JTable table;
private JButton next, back, btnClear, btnNewButton, btnChooseAll;
private JobList fnnJobList = new JobList();
private JobSelectionListPanel() {
table = new JTable();
JScrollPane scrollPane = new JScrollPane(table);
table.setBorder(new CompoundBorder());
// Read all FNN jobs from file
try {
fnnJobList.readFromFile("rules.csv");
} catch (IOException e1) {
System.out.println("You are not able to read the rules.csv file");
}
// Create ArrayList of JobNames
Object[][] initialData = new Object[fnnJobList.size()][1];
int i = 0;
for (Job jobDes : fnnJobList) {
initialData[i][0] = (Object) jobDes.getJobname();
i++;
}
String[] columnNames = new String[] { "", "Your preferences" };
table.setModel(new DefaultTableModel(initialData, columnNames) {
private static final long serialVersionUID = 1L;
#SuppressWarnings("rawtypes")
Class[] columnTypes = new Class[] { Object.class, Boolean.class };
#SuppressWarnings({ "unchecked", "rawtypes" })
public Class getColumnClass(int columnIndex) {
return columnTypes[columnIndex];
}
});
table.getColumnModel().getColumn(1).setPreferredWidth(80);
table.getColumnModel().getColumn(1).setMinWidth(40);
table.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
table.setCellSelectionEnabled(true);
I user want to choose all rows then I implemented this.
btnChooseAll = new JButton("Choose all");
btnChooseAll.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
DefaultTableModel chooseAllData = (DefaultTableModel) table.getModel();
if (DeviceGroups.DeviceAList.size() == 0 || DeviceGroups.DeviceBList.size() == 0
|| DeviceGroups.DeviceCList.size() == 0 || DeviceGroups.DeviceDList.size() == 0)
JOptionPane.showMessageDialog(null,
"You should choose at least 1 device for each test device to apply this test case", "Invalid OPTION",
JOptionPane.ERROR_MESSAGE);
else
for (int i = 0; i < chooseAllData.getRowCount(); i++) {
for (int j = 1; j < chooseAllData.getColumnCount(); j++) {
chooseAllData.setValueAt(true, i, j);
}
}
}
});
For clear all preferences :
btnClear = new JButton("Clear all");
// Clear button create a model of JTable and delete all the rows of table!!
btnClear.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
DefaultTableModel clearTableData = (DefaultTableModel) table.getModel();
for (int i = 0; i < clearTableData.getRowCount(); i++) {
for (int j = 1; j < clearTableData.getColumnCount(); j++) {
clearTableData.setValueAt(null, i, j);
}
}
}
});

I see the following problem in your code: mixing up view indexes and model indexes. This is the offending snippet:
for (int i = 0; i < table.getRowCount(); i++) {
if (table.getValueAt(i, 1) != null) {
if (((Boolean) table.getValueAt(i, 1)).booleanValue()) {
String jobName = (((DefaultTableModel) table.getModel()).getValueAt(i, 0).toString());
You are using the i variable to denote view row indices, since you are checking values in this statement: table.getValueAt(i, 1) != null.
But then a bit further you are using i to index the model:
String jobName = ((DefaultTableModel) table.getModel()).getValueAt(i, 0).toString();
If i is to be a view index, you need to convert it to a model index before indexing the model:
String jobName = ((DefaultTableModel) table.getModel()).getValueAt(table.convertRowIndexToModel(i), 0).toString();
Also, when columns would be switched around in the view (ie on screen in your GUI), the following will probably not work as intended:
table.getValueAt(i, 1) != null
You most likely mean to say, get the second column value in the model, not the view. Best rewrite then as
table.getValueAt(i, table.convertColumnIndexToView(1)) != null

Validate if jtable is empty?

I need to know how to check if there is data in a JTable something like
if(jTextField1.getText().isEmpty()):
then (if jTable1.isEmpty())
...
how I do that?

JTables are not simple components like the jtextfield, like other swing components they have an underlying Data Model, check this example from the javadoc:
TableModel dataModel = new AbstractTableModel() {
public int getColumnCount() { return 10; }
public int getRowCount() { return 10;}
public Object getValueAt(int row, int col) { return new Integer(row*col); }
};
JTable table = new JTable(dataModel);
Like in every UI object that follows the MVC pattern, you don't use the graphical component to understand the values it has, you use the data model. In you case, save a reference to the Data Model of the JTable you created and call getRowCount to know how much data you have previously loaded.
Also, check the official docs here.

I validate if the jtable is empty with
this code.
private int calculate() {
Vector<Integer> myvector = new Vector();
TableModel mode = new DefaultTableModel();
mode = jTable2.getModel();
int n = mode.getRowCount();
for (int i = 0; i < n; i++) {
if (mode.getValueAt(i, 3) != null) {
myvector.add((Integer) mode.getValueAt(i, 3));
}
}
return myvector.size();
}
//then I validate with a button
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
int numofvalidrows;
numofvalidrows = calculate();
if (numofvalidrows == 0) //if the size of the vector is 0 then the jtable is empty
{
System.out.println("You need to add people to the jtable, because the table is empty");
} else {
// I get the values of the jtable with
for (int i = 0; i < n; i++) {
if (model.getValueAt(i, 3) != null) { //whith this "if" I print only data, not print null of the empty cells in jtable
System.out.print(model.getValueAt(i, 3))
}
}
}
}

Java Swing JTable: cannot access the values in the table due to incorrect usage/creation of table model

I am just beginning to program using Java Swing. I am not very familiar with each of the many Java Swing Classes, and have ran into a stumbling block regarding the creation of a Table.
I am trying to figure out how to add a table to a Java Swing Program I am making. I have looked at docs.oracle.com to try and figure it out but I am getting an error when I try to access the values of the table. I will include my code to help show what I am currently trying to do and where the error is.
This is my code for making the table and the table model (I think the problem is that my table model is not working correctly):
/*Create the Table Entry*/
columnNames = new String[listoffields.size()+1];
columnNames[0] = "Record Number";
for(int a = 1; a < columnNames.length;a++){
columnNames[a] = listoffields.get(a-1).getTitle();
}
int count = 1;
data = new Object[numrecords][listoffields.size()+1];
for(int a = 0; a < numrecords;a++){
for(int b = 0; b < listoffields.size()+1;b++){
if(b == 0){
data[a][b] = count;
count++;
}
else{
data[a][b] = "";
}
}
}
/* create the table */
JTable table = new JTable(data,columnNames);
table.setCellSelectionEnabled(true);
table.setModel(new AbstractTableModel() {
public String getColumnName(int col) {
return columnNames[col].toString();
}
public int getRowCount() { return data.length; }
public int getColumnCount() { return columnNames.length; }
public Object getValueAt(int row, int col) {
return data[row][col];
}
public boolean isCellEditable(int row, int col) {
return (col >= 1);
}
public void setValueAt(Object value, int row, int col) {
data[row][col] = value;
fireTableCellUpdated(row, col);
}
});
JScrollPane scrollPane = new JScrollPane(table);
table.setFillsViewportHeight(true);
/* addthe table to the JTable tableentry*/
tabelentry.setLayout(new BoxLayout(ProjectFrame.tabelentry, BoxLayout.Y_AXIS));
tabelentry.add(scrollPane);
tabelentry.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
After the table is displayed and I edit the blank values for each cell, I click a submit button that submits the cell. However, the following error is encountered:
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 0 >= 0
at java.util.Vector.elementAt(Unknown Source)
at javax.swing.table.DefaultTableModel.getValueAt(Unknown Source)
at Client.GUIComponents.ProjectFrame$1.submit(NameOfFile.java:LineNumber)
The error is encountered when trying to submit as follows:
public void submit(){
String recordvalues = ""; //contains a String representation of what I want to submit
for(int a = 0; a < numberoffields;a++){
for(int b = 0; b < numberofrecords;b++){
if(a != 0){ //I want to skip the first column
recordvalues = recordvalues + (String) tabelentry.getModel().getValueAt(b, a) + ","; //The error is at this line in the code
}
}
}
}
I provided my code to give an example of the current problems I am encountering and what I have currently tried. To generalize my question, I am wondering how to correctly write a table model class so that I can access the values at each of the cells in the table. Any assistance would be helpful. Thanks a ton!

My immediate thought is that you're creating two different table models.
JTable table = new JTable(data,columnNames);
table.setCellSelectionEnabled(true);
table.setModel(new AbstractTableModel() {...
new JTable(data,columnNames) is actually creating it's own DefaultTableModel based on the information you are providing it. Try removing the table.setModel(new AbstractTableModel() {... code
The other, associated, problem is, I don't know how data and columnNames are declared.
Have a read through How to Use Tables for more details
Updated
The other problem, as pointed about by Hovercraft, is you adding one table to another and then accessing the wrong model.
The table creation should look more like...
tableEntry = new JTable(data,columnNames);
JScrollPane scrollPane = new JScrollPane(tableEntry );
tableEntry .setFillsViewportHeight(true);
// Don't forget to add the scroll pane to you view !!
Then you submit method should look more like...
public void submit(){
String recordvalues = ""; //contains a String representation of what I want to submit
TableModel model = tableEntry.getModel();
for(int a = 0; a < model.getColumnCount();a++){
for(int b = 0; b < model.getRowCount();b++){
if(a != 0){ //I want to skip the first column
recordvalues = recordvalues + (String) model.getValueAt(b, a) + ","; //The error is at this line in the code
}
}
}
}

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 0 >= 0
This exception means that the column size of your table is 0, I think it's because you don't add columns into your TableModel.
Try to create several TableColumn Column = new TableColumn(); then add these columns to your table

JTable hide and show columns

I want to add some columns to a table (Swing JTable). Some of them will have a default size (e.g. 250), others will be hidden (so their size will be 0). I use this code:
model = new DefaultTableModel();
table = new JTable(model);
setAutoResizeMode(AUTO_RESIZE_OFF);
for (int i = 1; i < COLUMN_NAMES.length; i++) {
model.addColumn(COLUMN_NAMES[i]);
if (show[i]) show(index);
else hide(index);
}
........
private void hide(int index) {
TableColumn column = getColumnModel().getColumn(index);
column.setMinWidth(0);
column.setMaxWidth(0);
column.setWidth(0);
column.setPreferredWidth(0);
doLayout();
}
private void show(int index) {
final int width = 250;
column.setMinWidth(15);
column.setMaxWidth(width);
column.setWidth(width);
column.setPreferredWidth(width);
doLayout();
}
the problem is when the table is displayed, all the columns are showed (none is hidden) and their size is not 250 but they have all the same size.
How can I get the wanted effect?

I think you have named your methods incorrectly, when you want to hide a column you will set
column.setMinWidth(0);
column.setMaxWidth(0);
column.setPreferredWidth(0);
but in your code you are doing this when you want to show a column which is exactly opposite.
Also there is no need to call this "setWidth" method on a TableColumn, read TableColumn#setWidth(int).

JTable#removeColumn remove Column only from JTable view, more in this example

instead of re-inventing the wheel you might consider to use JXTable (in the SwingX project) which supports hidden columns, comlete with a ui-control to allow users hiding/showing them dynamically - and a bunch of other useful thingies :).

try this something like this for example:
myTableModel = new DefaultTableModel();
myTableModel.setColumnIdentifiers(new Object[]{"ID", "Name"});
JTable myTable = new JTable(myTableModel);
// remember to save the references
TableColumn myTableColumn0 = guiLoteryNumbersTable.getColumnModel().getColumn(0);
TableColumn myTableColumn1 = guiLoteryNumbersTable.getColumnModel().getColumn(1);
//...
// remove temporary the column ("hide")
myTable.getColumnModel().removeColumn(myTableColumn1);
// then you restore that column when you need it ("show")
myTable.getColumnModel().addColumn(myTableColumn1);
That's the best way I know to hide a column.

HashMap<String,TableColumn> hashMap_columns = new HashMap<String,TableColumn>();
DefaultTableColumnModel defaultTableColumnModel = (DefaultTableColumnModel)jtable.getColumnModel();
Enumeration<TableColumn> enumeration = defaultTableColumnModel.getColumns();
while (enumeration.hasMoreElements())
{
TableColumn tableColumn = enumeration.nextElement();
hashMap_columns.put((String)tableColumn.getIdentifier(),tableColumn);
}
public void setColumnVisible(String identifier, boolean setVisible)
{
TableColumn tableColumn = hashMap_columns.get(identifier);
if (setVisible)
{
// using a sorted map removes the need to check column index/position
SortedMap<Integer,TableColumn> sortedMap = new TreeMap<Integer,TableColumn>();
// retreive all visible columns
Enumeration<TableColumn> enumeration = defaultTableColumnModel.getColumns();
while (enumeration.hasMoreElements())
{
TableColumn column = enumeration.nextElement();
sortedMap.put(column.getModelIndex(),column);
}
// add the column of interest to the sorted map
sortedMap.put(tableColumn.getModelIndex(),tableColumn);
// remove all visible columns
for (TableColumn column: sortedMap.values())
{
defaultTableColumnModel.removeColumn(column);
}
// add all previously visible columns as well as the column of interest
for (TableColumn column: sortedMap.values())
{
defaultTableColumnModel.addColumn(column);
}
}
else
{
defaultTableColumnModel.removeColumn(tableColumn);
}
}

public class TableColumnHider {
private final JTable table;
private final TableColumnModel tcm;
private final Map hiddenColumns;
public TableColumnHider(JTable table) {
this.table = table;
tcm = table.getColumnModel();
hiddenColumns = new HashMap();
}
public void hide(String columnName, String keySig) {
int index = tcm.getColumnIndex(columnName);
TableColumn column = tcm.getColumn(index);
hiddenColumns.put(columnName, column);
hiddenColumns.put(keySig + columnName, new Integer(index));
tcm.removeColumn(column);
}
public void show(String columnName, String keySig) {
Object o = hiddenColumns.remove(columnName);
if (o == null) {
return;
}
tcm.addColumn((TableColumn) o);
o = hiddenColumns.remove(keySig + columnName);
if (o == null) {
return;
}
int column = ((Integer) o).intValue();
int lastColumn = tcm.getColumnCount() - 1;
if (column < lastColumn) {
tcm.moveColumn(lastColumn, column);
}
}
}