How to completely erase a Java Swing JTable column and its data? - java

I'm trying to create a dynamic JTable in Java Swing where users can add/delete rows and columns as they want. Everything is good, except for deleting the column. I've been at this for hours now and I can't figure out how to completely erase a column and its values.
There are removeColumn(int) methods in the classes, but they only hide the column from view. I've also searched and found this answer, but when I try to create the CustomTableModel class and extend DefaultTableModel, I just get a ClassCastException.


Adding a column
Determine the new index of the column (how you do this is up to you)
Determine the new values for each row/column - you could also just as easily set the values to null to start with
Update the row data in the model
Update the column data in the model (ie columnCount and columnName)
Trigger a TableModelEvent.HEADER_ROW event so that the JTable updates itself with the new data
Removing a column
Determine the column index to be removed
Remove the column data for each row
Update the column data in the model (ie columnCount and columnName)
Trigger a TableModelEvent.HEADER_ROW event so that the JTable updates itself with the new data
Runnable example
This is a basic example of the concept. Personally I prefer to manage my data via POJOs (which is here the idea of "hiding columns" would be more practical, but that might not always be possible
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private MutableTableModel model;
private JTable table;
public TestPane() {
setLayout(new BorderLayout());
JButton addColumnButton = new JButton("Add column");
JButton removeColumnButton = new JButton("Remove column");
addColumnButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
List<Object> rows = new ArrayList<>(100);
for (int row = 0; row < 100; row++) {
rows.add(randomString());
}
String columnName = JOptionPane.showInputDialog(TestPane.this, "Column name");
if (columnName == null || columnName.isBlank()) {
columnName = randomString();
}
int columnIndex = table.getSelectedColumn();
if (columnIndex < 0) {
model.addColumn(columnName, rows);
} else {
model.addColumn(columnName, rows, columnIndex + 1);
}
}
});
removeColumnButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
int columnIndex = table.getSelectedColumn();
if (columnIndex < 0) {
JOptionPane.showMessageDialog(TestPane.this, "Now column selected");
} else {
model.removeColumn(columnIndex);
}
}
});
JPanel actionPanels = new JPanel(new GridBagLayout());
actionPanels.add(addColumnButton);
actionPanels.add(removeColumnButton);
add(actionPanels, BorderLayout.SOUTH);
String[] columnNames = new String[]{"One", "Two", "Three", "Four", "Five"};
List<List<Object>> rows = new ArrayList<>(100);
for (int row = 0; row < 100; row++) {
List<Object> rowData = new ArrayList<>(columnNames.length);
for (int col = 0; col < columnNames.length; col++) {
rowData.add(randomString());
}
rows.add(rowData);
}
model = new MutableTableModel(Arrays.asList(columnNames), rows);
table = new JTable(model);
add(new JScrollPane(table));
}
private Random random = new Random();
protected String randomString() {
int leftLimit = 48; // numeral '0'
int rightLimit = 122; // letter 'z'
int targetStringLength = 10;
String generatedString = random.ints(leftLimit, rightLimit + 1)
.filter(i -> (i <= 57 || i >= 65) && (i <= 90 || i >= 97))
.limit(targetStringLength)
.collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append)
.toString();
return generatedString;
}
}
public class MutableTableModel extends AbstractTableModel {
private ArrayList<List<Object>> rows = new ArrayList<>(32);
private ArrayList<String> columnNames = new ArrayList<>(8);
public MutableTableModel() {
}
public MutableTableModel(List<String> columnNames, List<List<Object>> rows) {
this.columnNames = new ArrayList<>(columnNames);
this.rows = new ArrayList<>(rows);
}
public void addColumn(String name) {
addColumn(name, columnNames.size() - 1);
}
public void addColumn(String name, int columnIndex) {
columnIndex = Math.max(0, Math.min(columnIndex, columnNames.size()));
int rowCount = getRowCount();
List<Object> rows = new ArrayList<>(rowCount);
for (int row = 0; row < rowCount; row++) {
rows.add(null);
}
addColumn(name, rows, columnIndex);
}
public void addColumn(String name, List<Object> rows) {
addColumn(name, rows, columnNames.size());
}
public void addColumn(String name, List<Object> newRows, int columnIndex) {
columnIndex = Math.max(0, Math.min(columnIndex, columnNames.size()));
columnNames.add(columnIndex, name);
int rowCount = getRowCount();
for (int row = 0; row < rowCount; row++) {
List<Object> rowData = rows.get(row);
Object value = null;
if (row < newRows.size()) {
value = newRows.get(row);
}
rowData.add(columnIndex, value);
}
fireTableStructureChanged();
}
public void removeColumn(int columnIndex) {
if (columnIndex < 0 || columnIndex >= columnNames.size()) {
return;
}
int rowCount = getRowCount();
for (int row = 0; row < rowCount; row++) {
List<Object> rowData = rows.get(row);
rowData.remove(columnIndex);
}
columnNames.remove(columnIndex);
fireTableStructureChanged();
}
#Override
public int getRowCount() {
return rows.size();
}
#Override
public int getColumnCount() {
return columnNames.size();
}
#Override
public String getColumnName(int column) {
if (column >= columnNames.size()) {
return super.getColumnName(column);
}
return columnNames.get(column);
}
#Override
public Object getValueAt(int rowIndex, int columnIndex) {
return rows.get(rowIndex).get(columnIndex);
}
}
}


Thanks to camickr for knocking my head back in place, I really just had to set the model to CustomTableModel so I could cast it back using getModel() as well. It now works using the answer in here. If you're using NetBeans, be sure to edit the autogenerated code yourself and change...
contentTable.setModel(new TableModel(
new Object [][] {
},
new String [] {
}
));
to
contentTable.setModel(new CustomTableModel(
new Object [][] {
},
new String [] {
}
));

Related

How can i add checkbox on my JTable?

This is a Drag and Drop Java Swing
Here's my code
prod.removeColumn(prod.getColumnModel().getColumn(0));
String sql = "select prod_id,prod_description,prod_wh_name,prod_fr_name from product order by prod_description asc";
PreparedStatement pst = con.prepareStatement(sql);
ResultSet rs = pst.executeQuery();
while(rs.next())
{
int columns = rs.getMetaData().getColumnCount();
Object[] row = new Object[columns];
for(int i = 1 ; i <=columns;i++)
{
row[i - 1] = rs.getObject(i);
}
((DefaultTableModel) prod.getModel()).insertRow(rs.getRow() -1,row);
}
I want to add a checkbox on the left side of every data in jtable(Prod Description), Any solution for that? and can select more than one? and how can i get the data of the selected item? Thanks in advance!

One way is to create a "wrapper" TableModel.
In this example a column containing check marks will be added to the left of the columns in any existing TableModel:
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
public class CheckBoxWrapperTableModel extends AbstractTableModel
{
private ArrayList<Boolean> checkBoxes = new ArrayList<>();
private DefaultTableModel model;
private String columnName;
public CheckBoxWrapperTableModel(DefaultTableModel model, String columnName)
{
this.model = model;
this.columnName = columnName;
for (int i = 0; i < model.getRowCount(); i++)
checkBoxes.add( Boolean.FALSE );
}
#Override
public String getColumnName(int column)
{
return (column > 0) ? model.getColumnName(column - 1) : columnName;
}
#Override
public int getRowCount()
{
return model.getRowCount();
}
#Override
public int getColumnCount()
{
return model.getColumnCount() + 1;
}
#Override
public Object getValueAt(int row, int column)
{
if (column > 0)
return model.getValueAt(row, column - 1);
else
{
Object value = checkBoxes.get(row);
return (value == null) ? Boolean.FALSE : value;
}
}
#Override
public boolean isCellEditable(int row, int column)
{
if (column > 0)
return model.isCellEditable(row, column - 1);
else
return true;
}
#Override
public void setValueAt(Object value, int row, int column)
{
if (column > 0)
model.setValueAt(value, row, column - 1);
else
{
checkBoxes.set(row, (Boolean)value);
}
fireTableCellUpdated(row, column);
}
#Override
public Class getColumnClass(int column)
{
return (column > 0) ? model.getColumnClass(column - 1) : Boolean.class;
}
public void removeRow(int row)
{
checkBoxes.remove(row);
fireTableRowsDeleted(row, row);
model.removeRow(row);
}
private static void createAndShowGUI()
{
// Create the table with check marks in the first column
DefaultTableModel model = new DefaultTableModel(5, 1);
for (int i = 0; i < model.getRowCount(); i++)
{
model.setValueAt("" + i, i, 0);
}
CheckBoxWrapperTableModel wrapperModel = new CheckBoxWrapperTableModel(model, "Select");
JTable table = new JTable(wrapperModel);
// Add button to delete selected rows
JButton button = new JButton( "Delete Selected Rows" );
button.addActionListener( new ActionListener()
{
#Override
public void actionPerformed(ActionEvent e)
{
for (int i = table.getRowCount() - 1; i >= 0; i--)
{
Boolean selected = (Boolean)table.getValueAt(i, 0);
System.out.println(selected + " : " + i);
if (selected)
{
wrapperModel.removeRow(i);
}
}
}
});
JFrame frame = new JFrame("SSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( new JScrollPane( table ) );
frame.add( button, BorderLayout.PAGE_END );
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater( () -> createAndShowGUI() );
/*
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
*/
}
}
This allows you to add the check box even if you don't have access to the original TableModel when it is created to add your own column of check boxes.

Move row with mouse in JTable

I have JTable with some rows. I want when move one row with mouse(drag and drop) that row to move together with mouse and table rows to be reorder when mouse move(like moving JTable's columns).
This jsfiddle is exactly what i want but i have to do it in java swing(or gif image below. Example is from here but I can't understand it).
My TransferHandler :
public class TableRowTransferHandler extends TransferHandler {
private final DataFlavor localObjectFlavor = new ActivationDataFlavor(Integer.class, "application/x-java-Integer;class=java.lang.Integer", "Integer Row Index");
private JTable table = null;
private static final Logger logger = Logger.getLogger(TableRowTransferHandler.class.getName());
public TableRowTransferHandler(JTable table) {
this.table = table;
}
#Override
protected Transferable createTransferable(JComponent c) {
assert (c == table);
return new DataHandler(table.getSelectedRow(), localObjectFlavor.getMimeType());
}
#Override
public boolean canImport(TransferHandler.TransferSupport info) {
boolean b = info.getComponent() == table && info.isDrop() && info.isDataFlavorSupported(localObjectFlavor);
table.setCursor(b ? DragSource.DefaultMoveDrop : DragSource.DefaultMoveNoDrop);
return b;
}
#Override
public int getSourceActions(JComponent c) {
return TransferHandler.COPY_OR_MOVE;
}
#Override
public boolean importData(TransferHandler.TransferSupport info) {
JTable target = (JTable) info.getComponent();
JTable.DropLocation dl = (JTable.DropLocation) info.getDropLocation();
int index = dl.getRow();
int max = table.getModel().getRowCount();
if (index < 0 || index > max) {
index = max;
}
target.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
try {
Integer rowFrom = (Integer) info.getTransferable().getTransferData(localObjectFlavor);
if (rowFrom != -1 && rowFrom != index) {
((Reorderable) table.getModel()).reorder(rowFrom, index);
if (index > rowFrom) {
index--;
}
target.getSelectionModel().addSelectionInterval(index, index);
return true;
}
} catch (UnsupportedFlavorException | IOException e) {
e.printStackTrace();
logger.log(Level.SEVERE, null, e);
}
return false;
}
#Override
protected void exportDone(JComponent c, Transferable t, int act) {
if ((act == TransferHandler.MOVE) || (act == TransferHandler.NONE)) {
table.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
}
}
}
That is a simple settings that i use to JTable:
childrenTable.setDragEnabled(true);
childrenTable.setDropMode(DropMode.INSERT);
childrenTable.setTransferHandler(new TableRowTransferHandler(childrenTable));
childrenTable.setRowSelectionAllowed(true);
childrenTable.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
At the moment when you move row with mouse between rows only have one bold line(Like this in red ellipse below in image). If it is impossible to do rows to move like this, i want this bold line to appear to whole row (not only in one cell).

Read the section from the Swing tutorial on Drag and Drop for the basics.
Here is some old code I found somewhere on the web with a custom TransferHandler to support a JTable:
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.event.*;
import java.io.IOException;
public class DnD_Demo extends JFrame {
public DnD_Demo() {
setTitle("DnD Demo (Version 3)");
JTextArea tips = new JTextArea("1. Select a row in Table A. " +
"Press the row again and drag. \n " +
"As you drag the cursor icon over Table B, the row that is currently under the cursor highlights " +
"- the new data will be inserted after the selected row. \n " +
"Drop the row onto Table B. Note that the row has been removed from Table A, " +
"and now appears in Table B. \n" +
"2. Select two rows from Table A and drop onto Table B. " +
"Now there are two new rows in Table B. ");
tips.setEditable(false);
tips.setBackground(new Color(255,255,204));
tips.setBorder(new LineBorder(Color.orange,5));
getContentPane().add(tips,BorderLayout.NORTH);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel(new GridLayout(2,1));
panel.add(createTable("Table A"));
panel.add(createTable("Table B"));
getContentPane().add(panel,BorderLayout.CENTER);
pack();
}
private JPanel createTable(String tableId) {
DefaultTableModel model = new DefaultTableModel();
model.addColumn("Column 0");
model.addColumn("Column 1");
model.addColumn("Column 2");
model.addColumn("Column 3");
model.addRow(new String[]{tableId+" 00", tableId+" 01", tableId+" 02", tableId+" 03"});
model.addRow(new String[]{tableId+" 10", tableId+" 11", tableId+" 12", tableId+" 13"});
model.addRow(new String[]{tableId+" 20", tableId+" 21", tableId+" 22", tableId+" 23"});
model.addRow(new String[]{tableId+" 30", tableId+" 31", tableId+" 32", tableId+" 33"});
JTable table = new JTable(model);
table.getTableHeader().setReorderingAllowed(false);
table.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION);
JScrollPane scrollPane = new JScrollPane(table);
scrollPane.setPreferredSize(new Dimension(400,100));
table.setDragEnabled(true);
table.setTransferHandler(new TableTransferHandler());
JPanel panel = new JPanel();
panel.add(scrollPane);
panel.setBorder(BorderFactory.createTitledBorder(tableId));
return panel;
}
public static void main(String[] args) {
new DnD_Demo().setVisible(true);
}
abstract class StringTransferHandler extends TransferHandler {
protected abstract String exportString(JComponent c);
protected abstract void importString(JComponent c, String str);
protected abstract void cleanup(JComponent c, boolean remove);
protected Transferable createTransferable(JComponent c) {
return new StringSelection(exportString(c));
}
public int getSourceActions(JComponent c) {
return COPY_OR_MOVE;
}
public boolean importData(JComponent c, Transferable t) {
if (canImport(c, t.getTransferDataFlavors())) {
try {
String str = (String)t.getTransferData(DataFlavor.stringFlavor);
importString(c, str);
return true;
} catch (UnsupportedFlavorException ufe) {
} catch (IOException ioe) {
}
}
return false;
}
protected void exportDone(JComponent c, Transferable data, int action) {
cleanup(c, action == MOVE);
}
public boolean canImport(JComponent c, DataFlavor[] flavors) {
for (int i = 0; i < flavors.length; i++) {
if (DataFlavor.stringFlavor.equals(flavors[i])) {
return true;
}
}
return false;
}
}
class TableTransferHandler extends StringTransferHandler {
public JTable target;
public int[] rows = null;
public int addIndex = -1; //Location where items were added
public int addCount = 0; //Number of items added.
protected String exportString(JComponent c) {
JTable table = (JTable)c;
rows = table.getSelectedRows();
int colCount = table.getColumnCount();
StringBuffer buff = new StringBuffer();
for (int i = 0; i < rows.length; i++) {
for (int j = 0; j < colCount; j++) {
Object val = table.getValueAt(rows[i], j);
buff.append(val == null ? "" : val.toString());
if (j != colCount - 1) {
buff.append(",");
}
}
if (i != rows.length - 1) {
buff.append("\n");
}
}
return buff.toString();
}
protected void importString(JComponent c, String str) {
target = (JTable)c;
DefaultTableModel model = (DefaultTableModel)target.getModel();
int index = target.getSelectedRow();
//Prevent the user from dropping data back on itself.
//For example, if the user is moving rows #4,#5,#6 and #7 and
//attempts to insert the rows after row #5, this would
//be problematic when removing the original rows.
//So this is not allowed.
if (rows != null && index >= rows[0] - 1 &&
index <= rows[rows.length - 1]) {
rows = null;
return;
}
int max = model.getRowCount();
if (index < 0) {
index = max;
} else {
index++;
if (index > max) {
index = max;
}
}
addIndex = index;
String[] values = str.split("\n");
addCount = values.length;
int colCount = target.getColumnCount();
for (int i = 0; i < values.length ; i++) {
model.insertRow(index++, values[i].split(","));
}
//If we are moving items around in the same table, we
//need to adjust the rows accordingly, since those
//after the insertion point have moved.
if (rows!= null && addCount > 0) {
for (int i = 0; i < rows.length; i++) {
if (rows[i] > addIndex) {
rows[i] += addCount;
}
}
}
}
protected void cleanup(JComponent c, boolean remove) {
JTable source = (JTable)c;
if (remove && rows != null) {
DefaultTableModel model =
(DefaultTableModel)source.getModel();
for (int i = rows.length - 1; i >= 0; i--) {
model.removeRow(rows[i]);
}
}
rows = null;
addCount = 0;
addIndex = -1;
}
}
}

I think that ListTransferHandler.java for item swapping of JList in the Swing tutorial will be also helpful.
Here is an example that I modified ListTransferHandler for JTable:
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import java.awt.event.*;
import java.io.IOException;
import java.util.*;
import java.util.List;
import javax.activation.*;
import javax.swing.*;
import javax.swing.table.*;
public final class TableRowsDnDTest {
private final TransferHandler handler = new TableRowTransferHandler();
private final String[] columnNames = {"String", "Integer", "Boolean"};
private final Object[][] data = {
{"AAA", 12, true}, {"aaa", 1, false},
{"BBB", 13, true}, {"bbb", 2, false},
{"CCC", 15, true}, {"ccc", 3, false},
{"DDD", 17, true}, {"ddd", 4, false},
{"EEE", 18, true}, {"eee", 5, false},
{"FFF", 19, true}, {"fff", 6, false},
{"GGG", 92, true}, {"ggg", 0, false}
};
private final TableModel model = new DefaultTableModel(data, columnNames) {
#Override public Class<?> getColumnClass(int column) {
switch (column) {
case 0:
return String.class;
case 1:
return Number.class;
case 2:
return Boolean.class;
default:
return super.getColumnClass(column);
}
}
};
private final JTable table = new JTable(model);
public JComponent makeUI() {
table.getSelectionModel().setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
table.setTransferHandler(handler);
table.setDropMode(DropMode.INSERT_ROWS);
table.setDragEnabled(true);
table.setFillsViewportHeight(true);
//table.setAutoCreateRowSorter(true); //XXX
//Disable row Cut, Copy, Paste
ActionMap map = table.getActionMap();
Action dummy = new AbstractAction() {
#Override public void actionPerformed(ActionEvent e) { /* Dummy action */ }
};
map.put(TransferHandler.getCutAction().getValue(Action.NAME), dummy);
map.put(TransferHandler.getCopyAction().getValue(Action.NAME), dummy);
map.put(TransferHandler.getPasteAction().getValue(Action.NAME), dummy);
JPanel p = new JPanel(new BorderLayout());
p.add(new JScrollPane(table));
p.setBorder(BorderFactory.createTitledBorder("Drag & Drop JTable"));
return p;
}
public static void main(String... args) {
EventQueue.invokeLater(() -> {
JFrame f = new JFrame();
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.getContentPane().add(new TableRowsDnDTest().makeUI());
f.setSize(320, 240);
f.setLocationRelativeTo(null);
f.setVisible(true);
});
}
}
//Demo - BasicDnD (Drag and Drop and Data Transfer) https://docs.oracle.com/javase/tutorial/uiswing/dnd/basicdemo.html
//Demo - DropDemo (Drag and Drop and Data Transfer) https://docs.oracle.com/javase/tutorial/uiswing/dnd/dropmodedemo.html
//#see https://docs.oracle.com/javase/tutorial/uiswing/examples/dnd/DropDemoProject/src/dnd/ListTransferHandler.java
//#see https://github.com/aterai/java-swing-tips/blob/master/DnDReorderTable/src/java/example/TableRowsDnDTest.java
class TableRowTransferHandler extends TransferHandler {
private final DataFlavor localObjectFlavor;
private int[] indices;
private int addIndex = -1; //Location where items were added
private int addCount; //Number of items added.
protected TableRowTransferHandler() {
super();
localObjectFlavor = new ActivationDataFlavor(Object[].class, DataFlavor.javaJVMLocalObjectMimeType, "Array of items");
}
#Override protected Transferable createTransferable(JComponent c) {
JTable table = (JTable) c;
DefaultTableModel model = (DefaultTableModel) table.getModel();
List<Object> list = new ArrayList<>();
indices = table.getSelectedRows();
for (int i : indices) {
list.add(model.getDataVector().get(i));
}
Object[] transferedObjects = list.toArray();
return new DataHandler(transferedObjects, localObjectFlavor.getMimeType());
}
#Override public boolean canImport(TransferHandler.TransferSupport info) {
JTable table = (JTable) info.getComponent();
boolean isDropable = info.isDrop() && info.isDataFlavorSupported(localObjectFlavor);
table.setCursor(isDropable ? DragSource.DefaultMoveDrop : DragSource.DefaultMoveNoDrop);
return isDropable;
}
#Override public int getSourceActions(JComponent c) {
return TransferHandler.MOVE;
}
#Override public boolean importData(TransferHandler.TransferSupport info) {
if (!canImport(info)) {
return false;
}
TransferHandler.DropLocation tdl = info.getDropLocation();
if (!(tdl instanceof JTable.DropLocation)) {
return false;
}
JTable.DropLocation dl = (JTable.DropLocation) tdl;
JTable target = (JTable) info.getComponent();
DefaultTableModel model = (DefaultTableModel) target.getModel();
int index = dl.getRow();
int max = model.getRowCount();
if (index < 0 || index > max) {
index = max;
}
addIndex = index;
target.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
try {
Object[] values = (Object[]) info.getTransferable().getTransferData(localObjectFlavor);
addCount = values.length;
for (int i = 0; i < values.length; i++) {
int idx = index++;
model.insertRow(idx, (Vector) values[i]);
target.getSelectionModel().addSelectionInterval(idx, idx);
}
return true;
} catch (UnsupportedFlavorException | IOException ex) {
ex.printStackTrace();
}
return false;
}
#Override protected void exportDone(JComponent c, Transferable data, int action) {
cleanup(c, action == TransferHandler.MOVE);
}
//If the remove argument is true, the drop has been
//successful and it's time to remove the selected items
//from the list. If the remove argument is false, it
//was a Copy operation and the original list is left
//intact.
protected void cleanup(JComponent c, boolean remove) {
if (remove && indices != null) {
c.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
DefaultTableModel model = (DefaultTableModel)((JTable) c).getModel();
//If we are moving items around in the same list, we
//need to adjust the indices accordingly, since those
//after the insertion point have moved.
if (addCount > 0) {
for (int i = 0; i < indices.length; i++) {
if (indices[i] >= addIndex) {
indices[i] += addCount;
}
}
}
for (int i = indices.length - 1; i >= 0; i--) {
model.removeRow(indices[i]);
}
}
indices = null;
addCount = 0;
addIndex = -1;
}
}

Java JTable mistake in copying rows

Good day!
There is a problem in downloaded program. You can copy a row by clicking on it by right mouse button, but after that when you change data in one cell data will be changed in every cell in column. Please, help me to understand, what I've missed.
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.AbstractTableModel;
public class Main extends JFrame{
JMenuItem obrc;
JTable table;
DataModel tm;
JScrollPane scrollTable;
Main() {
super("Example JTable");
Container c = getContentPane();
ArrayList<String> columnNames = new ArrayList<String>();
columnNames.add("Type"); columnNames.add("Sort"); columnNames.add("Thickness"); columnNames.add("Width");
tm = new DataModel(columnNames);
table = new JTable(tm);
c.add(new JScrollPane(table), BorderLayout.CENTER);
setSize(400, 300);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
table.getColumnModel().getColumn(0).setPreferredWidth(40);
table.getColumnModel().getColumn(1).setPreferredWidth(40);
table.addMouseListener(new MouseAdapter(){
public void mouseClicked(MouseEvent event) {
if (SwingUtilities.isRightMouseButton(event)) {
JPopupMenu obrcd = new JPopupMenu();
obrc = new JMenuItem("Copy");
obrc.addActionListener(new MenuListener());
obrcd.add(obrc);
obrcd.show(c, event.getX(), event.getY());
}
}
});
}
public class MenuListener implements ActionListener {
public void actionPerformed(ActionEvent e) {
int[] nums = table.getSelectedRows();
if (nums.length != 0) {
if (e.getSource() == obrc) {
ArrayList<Object[]> list = tm.getRows(nums);
tm.addRows(list);
}
else JOptionPane.showMessageDialog(null,
"Select at least one row", "Warning", JOptionPane.ERROR_MESSAGE);
}
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new Main();
}
});
}
class DataModel extends AbstractTableModel{
ArrayList<Object[]> data = new ArrayList<Object[]>();
ArrayList<String> columnNames = new ArrayList<String>();
public DataModel(ArrayList<String> cNames){
super();
columnNames = cNames;
Object[] dat = new Object[4];
dat[0] = "board";
dat[1] = "1";
dat[2] = "25";
dat[3] = "150";
data.add(dat);
}
public boolean isCellEditable(int rowIndex, int columnIndex)
{
return true;
}
public Object getValueAt(int rowIndex, int columnIndex){
Object[] row = data.get(rowIndex);
return row[columnIndex];
};
public void setValueAt(Object newValue, int rowIndex, int columnIndex){
data.get(rowIndex)[columnIndex] = newValue;
fireTableDataChanged();
}
public int getRowCount()
{
return data.size();
};
public int getColumnCount()
{
return columnNames.size();
};
public String getColumnName(int column)
{
return columnNames.get(column);
}
public ArrayList<Object[]> getRows(int[] nums) {
ArrayList<Object[]> newdata = new ArrayList<Object[]>();
for (int i = 0; i < nums.length; i++) {
newdata.add(data.get(nums[i]));
}
return newdata;
}
public void addRows (ArrayList<Object[]> rows) {
for (int i = 0; i < rows.size(); i++) data.add(rows.get(i));
fireTableDataChanged();
}
}
}

Problem when you are adding new rows
public void addRows (ArrayList<Object[]> rows) {
for (int i = 0; i < rows.size(); i++) data.add(rows.get(i));
fireTableDataChanged();
}
Your copied row(s) will point to same object(s) with selected row(s). You need clone to new object:
public void addRows (ArrayList<Object[]> rows) {
for (int i = 0; i < rows.size(); i++) {
Object[] clone = rows.get(i).clone();
data.add(clone);
}
fireTableDataChanged();
}

Getting single INT value from jTable

I have a table with two values: A and B
Is it possible to get A as int using getSelectedRow()?
At this moment I got this, it cannot find symbol for variable A
DefaultTableModel tm = (DefaultTableModel)jTabela.getModel();
int A = Integer.parseInt( tm.getValueAt(jTabela.A, getSelectedRow()).toString() );

You're putting the row number into the wrong parameter. Per the JTable API the getValueAt(...) method takes two int parameters, the first of which is the row index and the second is the column index. So you'll want something like:
DefaultTableModel tm = (DefaultTableModel)jTabela.getModel();
int row = tm.getSelectedRow();
if (row == -1) {
return;
}
Object value = jTabela.getValueAt(row, whateverYourColumnIs);
int intValue = value != null ? Integer.parseInt(value.toString()) : 0;
For example:
import java.awt.BorderLayout;
import java.util.Vector;
import javax.swing.*;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.table.DefaultTableModel;
#SuppressWarnings("serial")
public class TableExample extends JPanel {
private static final String[] COLUMNS = {"Name", "Value"};
private DefaultTableModel model = new DefaultTableModel(COLUMNS, 0) {
public java.lang.Class<?> getColumnClass(int columnIndex) {
Object value = getValueAt(0, columnIndex);
if (value == null) {
return super.getColumnClass(columnIndex);
} else {
return value.getClass();
}
};
};
private JTable table = new JTable(model);
public TableExample() {
for (int i = 0; i < 10; i++) {
String name = "Row " + (i + 1);
int value = (i + 1) * 10;
Vector<Object> row = new Vector<>();
row.add(name);
row.add(value);
model.addRow(row);
}
table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
table.getSelectionModel().addListSelectionListener(new ListSelectionListener() {
#Override
public void valueChanged(ListSelectionEvent e) {
if (e.getValueIsAdjusting()) {
return;
}
int row = table.getSelectedRow();
if (row == -1) {
return;
}
Object value = table.getValueAt(row, 1); // numbers are in row 1
if (value != null) {
System.out.println("Selected value: " + value);
int intValue = Integer.parseInt(value.toString());
// can use value here
}
}
});
setLayout(new BorderLayout());
add(new JScrollPane(table));
}
private static void createAndShowGui() {
JFrame frame = new JFrame("Table Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new TableExample());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

Adding icons to jTable in different rows

I have a jTable that I have created to display the names of countries and the flag icons in the cells next to the names. How can I display each icon in the same column but different rows using the ImageIcon class, without displaying just a string?
The following is what I have written to display the France flag icon at a certain place in the jTable but it just displays the string
ImageIcon icon = new ImageIcon("http://www.stoma.fr/assets/images/French_Flag_Small_Icon.jpg");
jTable.setValueAt(icon, 1, 2);

This is solved easily by simply making sure that the column for the icons returns Icon.class in the table model's getColumnClass(...) method. Fortunately JTables know how to display icons without any extra work if you do this. For example.
A modification of my code from there uses this table model:
DefaultTableModel model = new DefaultTableModel(COL_NAMES, 0) {
#Override
public Class<?> getColumnClass(int column) {
if (getRowCount() > 0) {
Object value = getValueAt(0, column);
if (value != null) {
return getValueAt(0, column).getClass();
}
}
return super.getColumnClass(column);
}
};
The whole program:
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
public class ImageColumnTest2 {
public static final String IMAGE_SHEET_PATH = "http://speckycdn.sdm.netdna-cdn.com/"
+ "wp-content/uploads/2010/08/flag_icons_04.jpg";
public static final String[] COUNTRIES = {
"Denmark", "China", "Chile", "Canada", "Belgium", "Austria",
"Argentina", "France", "Malaysina", "Lebanon", "Korea", "Japan",
"Italy", "Ireland", "India", "Hong Kong", "Greece", "Germany"
};
public static final int COLS = 6;
public static final int ROWS = 3;
private static final String[] COL_NAMES = {"Country", "Flag"};
private JTable table = new JTable();
private JScrollPane mainPane = new JScrollPane(table);
public ImageColumnTest2() throws IOException {
DefaultTableModel model = new DefaultTableModel(COL_NAMES, 0) {
#Override
public Class<?> getColumnClass(int column) {
if (getRowCount() > 0) {
Object value = getValueAt(0, column);
if (value != null) {
return getValueAt(0, column).getClass();
}
}
return super.getColumnClass(column);
}
};
URL url = new URL(IMAGE_SHEET_PATH);
BufferedImage img = ImageIO.read(url);
int x1 = 15; // sorry about the magic numbers
img = img.getSubimage(x1, 0, img.getWidth() - 2 * x1, img.getHeight());
int y1 = 20 ; // ditto!
int w = img.getWidth() / COLS;
int h = img.getHeight() / ROWS;
for (int row = 0; row < ROWS; row++) {
int y = (row * img.getHeight()) / ROWS;
for (int col = 0; col < COLS; col++) {
int x = (col * img.getWidth()) / COLS;
BufferedImage subImg = img.getSubimage(x, y, w, h);
subImg = subImg.getSubimage(x1, 0, subImg.getWidth() - 2 * x1, subImg.getHeight() - y1);
ImageIcon icon = new ImageIcon(subImg);
String country = COUNTRIES[col + row * COLS];
Object[] rowData = {country, icon};
model.addRow(rowData);
}
}
table.setModel(model);
table.setRowHeight(((ImageIcon)model.getValueAt(0, 1)).getIconHeight());
}
public JComponent getMainComponent() {
return mainPane;
}
private static void createAndShowGui() {
ImageColumnTest2 imgColumnTest = null;
try {
imgColumnTest = new ImageColumnTest2();
} catch (MalformedURLException e) {
e.printStackTrace();
System.exit(-1);
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
JFrame frame = new JFrame("ImageColumnTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(imgColumnTest.getMainComponent());
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Which displays as:

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