Sorry for being so amateur, I created a 'button' on a frame so that when we click the button for the first time, A ROW will be inserted on the frame. But ALL I WANT is that when I click the button THE SECOND TIME, the ROW IS REFRESHED (Not creating a new row!), I know that '.addRow(new Object[] { "", "", ""});' is the cause , because the object is created every time I click the button, so how could I possibly modify the code? Thanks for your attention.
*My weak brain said that if only I can empty 'model' object (or destroying the object, something like that), then I would find the solution, but how I could possibly empty/destroy that 'model' object?
import javax.swing.*;
import java.awt.event.*;
import javax.swing.table.DefaultTableModel;
public class MyTable extends JFrame {
private JTable table;
private DefaultTableModel model;
private JScrollPane scroll;
private JButton createRow;
private String headers[] = {"a", "b", "c"};
public MyTable() {
createRow = new JButton("Create Row");
model = new DefaultTableModel();
model.setColumnIdentifiers(headers);
table = new JTable();
table.setModel(model);
scroll = new JScrollPane(table);
add(createRow, java.awt.BorderLayout.NORTH);
add(scroll, java.awt.BorderLayout.CENTER);
createRowOn();
}
// while button is pressed then create A ROW
public void createRowOn() {
createRow.addActionListener(
new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getSource() == createRow) {
model.addRow(new Object[]{"", "", ""});
}
}
});
}
public static void main(String args[]) {
MyTable t = new MyTable();
t.setVisible(true);
t.setSize(300, 300);
}
}
Sorry for being so amateur
please read Oracle tutorial How to use Tables, especially part Creating Table Model
I created a 'button' on frame so that when we click the button for the
first time, A ROW will be inserted on frame. But all i want that when
i click the button on THE SECOND TIME , the ROW IS REFRESHED (Not
creating a new row !) , i suspect 'new Object[] { "", "", ""}' is the
cause , because the object is created everytime i click the button, so
how could i possibly modify the code ?
not clear from question (nothing is added to JTable) if you want to:
add a new row (model.addRow)
remove all rows (setDataVector/setRowCount)
reset value in JTables view (setValueAt)
but everything is described in Oracle tutorial, rest in the DefaultTableModel
Related
This question already has answers here:
Add Jbutton to each row of a Jtable
(1 answer)
Listening to key events for a component hierarchy
(4 answers)
Closed 5 years ago.
I have a program with an editable JTable. I am attempting to create a key binding for the table that will delete the rows selected by the user when the Delete key is pressed. This is the code for my key binding:
inventoryTable.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(KeyEvent.VK_DELETE, 0), "delete");
inventoryTable.getActionMap().put("delete", new RemoveSelectedAction());
However, when I press the Delete key while one or more rows are selected, no rows are deleted, and the selected cell displays its editor.
Having looked at the answers here and here, I suspect the problem is this: because my table is editable, the selected cell is intercepting the keypress before it reaches the JTable's key binding.
Am I correct in my assessment of why the Delete key is not behaving as desired?
How do I get the keypress to reach the JTable's binding?
UPDATE: When I changed my table model's isCellEditable method to return false for all cells, the key binding worked as expected, so I am now almost certain that the problem is the keypress being intercepted by the selected cell.
This is the code that produces the problem:
import javax.swing.*;
import java.awt.event.*;
public class TableDeleteRowsTest extends JFrame
{
public TableDeleteRowsTest()
{
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
String[] columnNames = { "A", "B", "C" };
Object[][] data = {
{ "foo", "bar", "baz" },
{ 1, 2, 3 }
};
JPanel contentPane = new JPanel();
JTable table = new JTable(data, columnNames);
table.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(
KeyStroke.getKeyStroke(KeyEvent.VK_DELETE, 0), "delete");
table.getActionMap().put("delete", new AbstractAction()
{
public void actionPerformed(ActionEvent e)
{
System.out.println("In the actual program, this will delete the rows currently selected by the user.");
}
});
contentPane.add(table);
contentPane.setOpaque(true);
setContentPane(contentPane);
}
public static void createAndShowGUI()
{
TableDeleteRowsTest test = new TableDeleteRowsTest();
test.pack();
test.setVisible(true);
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
}
}
2015.5.5 22:11 updated. I found that, when I create a sorter and call setRowSorter() method in the MyTable's construction, afterwards, it
will keep the original line number(in which the data still refresh
correctly but not easy to discover)even though the dataModel inside is
already changed many times which can be proven as
printf(getModel().getRowCount()). What's more,
MyTable.getAutoCreateRowSorter() always return true. I must explicitly
call setAutoCreateRowSorter(true) to fix the issue it if I called
setRowSorter(). I am happy but this is still wierd.
[2015.5.5 6:19 updated] I have found a way to access: make a "setRow" with the combination of insertRow() and removeRow() and everytime I
update, I setrRow all the rows in the table. It reflect immediately in
the UI. BUT there will be a series of error begin with "AWT-EventQueue-0" java.lang.IndexOutOfBoundsException: Invalid index" and I　guess it's about some kiind of swing thread problem because I can see "RepaintManager" or "paint" in the error. It occurs especially when I move the scrollbar when it's running.(but it still occur if I don't move it)
I have a JTable in a JScrollPane in a JFrame. I initial a MyTableModel with a data and use it to Create a JTable.Like this
MyTableModel extends DefaultTableModel{
Data data;
//object
MyTableModel (Data a){
data = a;
// do something to initial the table model,like build object[][] and add rows.
}
}
class main{
MyTableModel tm = new MyTableModel(data);
Jtable table = new JTable(tm);
JScrollpane jsp = new JScrollpane(table);
JFrame window = new JFrame();
window.getxxxpane().add(jsp);
}
So, as my data is always changing/updating and the changed row is plural and impossible to caculate.
while(true){
data.change();
refreshing the table to display the data immediately;
}
my idea is to simply build a new MyTableModel object and set it as the table's model like:
table.setModel(new MyTableModel(data)); //data had been changed.
which doesn't work.
and I tried this:
tm = MyTableModel(data);
tm.fireTableDataChanged();
which doesn't work either.
and the combination as well:
MyTableModol nm = new MyTableModel(data); //data had been changed
table.setModel(nm);
nm.fireTableDataChanged();
Could someone please give me some clue to change the TableModel object in an unchangable Jtable and update everytime.I dont want to change the tableModel Object because the calculation is huge, instead ,i Want to always create a new object with the construction method's parameter(changed data).
the most worst method is to remove the JScrollpane and rebuild one table/tablemodel/jscrollpane and re-add it, in which I have to call window.setVisible(true). window.repait() doesn't work,either,unless I move it.
I create a space-wasting but runnable program for demostration ,which most of them are nonsense.
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Formatter;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTabbedPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
class TM extends DefaultTableModel {
int[] inside;
static String[] columnNames = { "Hellium", "Radon",
};
TM(int[] data) {
super(columnNames, 0);
this.inside = data;
update();
}
void update() {
Object[][] data = new Object[2][columnNames.length];
for (int i = 0; i < 2; ++i) {
data[i][0] = inside[0];
data[i][1] = inside[1];
// setValueAt(aValue, row, column);
addRow(data[i]);
}
fireTableDataChanged();
}
}
class idkName {
TM tm;
JButton jb, jb2;
int data[] = { 1, 2 };
int data2[] = { 9, 10 };
JTable table;
JScrollPane jsp;
JFrame twindow;
idkName() {
JFrame window = new JFrame();
window.setSize(400, 400);
window.setLayout(new BorderLayout());
jb = new JButton("show");
jb2 = new JButton("change model");
window.add(jb, BorderLayout.EAST);
window.add(jb2, BorderLayout.WEST);
twindow = new JFrame();
jb.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent arg0) {
tm = new TM(data);
table = new JTable(tm);
jsp = new JScrollPane(table);
twindow.getContentPane().add(jsp);
twindow.setSize(500, 500);
twindow.setVisible(true);
}
});
window.setVisible(true);
jb2.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
// tm = new TM(data2);
tm = new TM(data2);
System.out.println(""+tm.getValueAt(0,0));
tm.fireTableDataChanged();
twindow.setVisible(true);
}
});
}
}
public class main2 {
TM tm;
public static void main(String[] args) {
idkName i = new idkName();
}
}
If you're going to extend DefaultTableModel, then when the data is changed, you need to update it in DefaultTableModel's internal representation using the setValueAt or setDataVector methods. If you have extensive changes (which it sounds like you do), use the setDataVector method to change all the cells and the table structure at once. Your example code looks like it's missing some updates because it's not pushing the new values in to the DefaultTableModel's data vectors.
But since you have a lot of updates, you're probably better off avoiding DefaultTableModel and just extending AbstractTableModel, using your own custom data storage, and calling the appropriate fireXxx() methods whenever your data changes. This will probably be more efficient in terms of both data conversion and number of events raised.
And then make sure all the event and value change work is done on the AWT event thread, using SwingWorkers or other threading support.
I have a code which displays Table in applets & consists of two columns:-
image icon
description
Here's my code:
import javax.swing.table.*;
public class TableIcon extends JFrame
{
public TableIcon()
{
ImageIcon aboutIcon = new ImageIcon("about16.gif");
ImageIcon addIcon = new ImageIcon("add16.gif");
ImageIcon copyIcon = new ImageIcon("copy16.gif");
String[] columnNames = {"Picture", "Description"};
Object[][] data =
{
{aboutIcon, "About"},
{addIcon, "Add"},
{copyIcon, "Copy"},
};
DefaultTableModel model = new DefaultTableModel(data, columnNames);
JTable table = new JTable( model )
{
// Returning the Class of each column will allow different
// renderers to be used based on Class
public Class getColumnClass(int column)
{
return getValueAt(0, column).getClass();
}
};
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane( table );
getContentPane().add( scrollPane );
}
public static void main(String[] args)
{
TableIcon frame = new TableIcon();
frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
frame.pack();
frame.setVisible(true);
}
}
Now what i want to know is how can I implement selection listener or mouse listener event on my table , such that it should select a particular image from my table and display on text area or text field(my table contains path of image file)?
Can I add text field on table & table on frame? Please feel free to ask queries if required.
In my code I have a table where I set single selection mode; in my case, listener described in How to Write a List Selection Listener (with a for loop from getMinSelectionIndex to getMaxSelectionIndex) is not useful because releasing mouse button I'm sure I have just one row selected.
So I've solved as follows:
....
int iSelectedIndex =-1;
....
JTable jtable = new JTable(tableModel); // tableModel defined elsewhere
jtable.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
ListSelectionModel selectionModel = jtable.getSelectionModel();
selectionModel.addListSelectionListener(new ListSelectionListener() {
public void valueChanged(ListSelectionEvent e) {
handleSelectionEvent(e);
}
});
....
protected void handleSelectionEvent(ListSelectionEvent e) {
if (e.getValueIsAdjusting())
return;
// e.getSource() returns an object like this
// javax.swing.DefaultListSelectionModel 1052752867 ={11}
// where 11 is the index of selected element when mouse button is released
String strSource= e.getSource().toString();
int start = strSource.indexOf("{")+1,
stop = strSource.length()-1;
iSelectedIndex = Integer.parseInt(strSource.substring(start, stop));
}
I think this solution, that does not require a for loop between start and stop to check which element is selectes, is more suitable when table is in single selection mode
How about this?
protected void handleSelectionEvent(ListSelectionEvent e) {
if (e.getValueIsAdjusting())
return;
final DefaultListSelectionModel target = (DefaultListSelectionModel)e.getSource();
iSelectedIndex = target.getAnchorSelectionIndex();
}
Read the section from the Swing tutorial on How to Write a List Selection Listener.
You can't add a text field to the table, but you can add a textfield and a table to the same frame.
Why won't table cell 0,1 change from aaa to XXXX?
import java.awt.*;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
class MainFrame {
public static void main(String[] args) {
JFrame f = new JFrame("Refreshing JTable");
JPanel p = new JPanel(new GridBagLayout());
DefaultTableModel productsModel;
JTable productsTable;
f.setSize(800, 600);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
String[] tableTitle = new String[] {"ID", "Name"};
String[][] tableData = {{"1", "AAA"},{"2", "BBB"}};
productsModel = new DefaultTableModel(tableData, tableTitle);
productsTable = new JTable(productsModel) {
public boolean isCellEditable(int r, int c) {
return false;
}
};
JScrollPane scrollpane = new JScrollPane(productsTable);
tableData[0][1] = "XXXX";
f.add(p);
p.add(scrollpane);
f.validate();
f.setVisible(true);
}
}
REASON:
Apparently trying to update the array where data is stored will result in JTable not changing. Either DefaultTableModel needs to be updated or the whole table needs to be redrawn.
EDIT (possible Solution) One way is using Timer:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
class MainFrame {
static JFrame f = new JFrame("Refreshing JTable");
static JPanel p = new JPanel(new GridBagLayout());
static DefaultTableModel productsModel;
static JTable productsTable;
public static void main(String[] args) {
runGui();
}
#SuppressWarnings("serial")
public static void runGui() {
f.setSize(800, 600);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
String[] tableTitle = new String[] {"ID", "Name"};
String[][] tableData = {{"1", "AAA"},{"2", "BBB"}};
productsModel = new DefaultTableModel(tableData, tableTitle);
productsTable = new JTable(productsModel) {
public boolean isCellEditable(int r, int c) {
return false;
}
};
JScrollPane scrollpane = new JScrollPane(productsTable);
tableData[0][1] = "XXXX";
Timer t = new Timer(2000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
addColumns();
remakeData();
productsTable.setModel(productsModel);
}
});
t.start();
f.add(p);
p.add(scrollpane);
f.validate();
f.setVisible(true);
}
private static void addColumns() {
productsModel.setColumnCount(0);
productsModel.addColumn("ID");
productsModel.addColumn("Name");
}
private static void remakeData() {
productsModel.setRowCount(0);
productsModel.insertRow(productsModel.getRowCount(), new Object[] {"1", "Dummy item 1"});
productsModel.insertRow(productsModel.getRowCount(), new Object[] {"2", "Dummy itme 2"});
productsModel.insertRow(productsModel.getRowCount(), new Object[] {"3", "Dummy item 3"});
productsModel.insertRow(productsModel.getRowCount(), new Object[] {"4", "Dummy item 4"});
productsModel.insertRow(productsModel.getRowCount(), new Object[] {"5", "Dummy item 5"});
}
}
EDIT(much better solution, the way it worked for me flawlessly) Using a static method. Since I'm adding new data in array through another Frame, I created a static method in MainFrame, which I call every time I add/update/delete Object in array. This method will redo the whole model after update and will therefore refresh table.
One problem with the SSCCE posted on your related thread is that the code changes the array which originally formed the table model, whereas it should be changing the table model itself.
The solution to your problem (and the previous one) is rather simple, but unfortunately a bit too long to post it in a comment
You make sure you do some reading on how a JTable actually works. A good starting point is the Swing tutorial and perhaps even the class javadoc of the most important classes JTable and TableModel. Another good read about Swing and the use of MVC is this document. It is much broader then only JTables but will provide you with more insight in how all Swing components are designed, and how you should use them.
After reading that tutorial, you should understand that if you want to update the data which is shown in the table, you update the model of your table. The model will fire events which are received by the table, and the table will make sure it updates itself. After all, the table is only a view on the data (=the TableModel) so updates on the take should take place on the model side. If this is not clear, go back to step 1
Now take a look at your code and remove the listener. Instead, update the model on the table and see how the table updates itself.
If this does not work, you come back to this site with an SSCCE which you post. That way we can see that you tried something, what you tried and most likely what is wrong in your code. This SSCCE should include your code of the TableModel you use and the code that updates your TableModel since that is the most likely location for your problem.
Brief description of a problem.
Assume we have JTable and user interacting with it in some way. TableModel of this table is constantly changing. How to ensure that when user tries to get some info from the table by referencing some constant column and currently selected row (by its rowIndex he got from JTable), he will not get into situation when TableModel is changed and his rowIndex obtained from JTable is no longer corresponding to same value in TableModel.
Following is initial question which explains problem in more detail:
Consider following situation:
There is JTable which shows user info about currently running requests in some system
When new request enters system, new row is being added to the table
user can interact with table by right-clicking on a row (single row selection model is used in table) and choosing option from the menu (like: abort, postpone, retry, etc.)
there is separate class which implements ActionListener interface (listens to the table) and handles all user interactions
When user does some action on the table this class checks currently selected row and assigns some values for user's action (basically it takes index of selected row and then calls tableModel.getValueAt(indexOfSelectedRow, someValuableDataColumnIndex))
Now consider scenario when system is under stress test and requests are being submitted constantly with big frequency. This, in my case, leads to a bug, when sometimes class which handles user's actions gets wrong info from table model (action was called on one row, but action is done for another, usually next one). I believe this happens because during some inits in action handling class table model is changed because of new request accepted.
Question is, how to fix this. I am thinking about two approaches:
use something like invokeAndWait() for initialization in my user actions' handling class (don't like this idea, because imo it will lead to other unpredictable bugs)
creating separate listener class which will listen to user selections in the table and store data from selected row as soon as it was selected separately from TableModel. This way actions handling class will take data not from table model which is being changed, but from selected row, which is constant during the described scenario. (not sure this idea will work)
Please, comment on my ideas, and suggest yours.
I am sorry for absence of any code here, but original code will take way too much space, and model example isn't something what can be done easily here.
I don't think inserting rows in a table changes the selection, so as long as you are updating the TableModel on the EDT, the selected row is still same when the user shows the popup and chooses and action from the popup.
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
public class TestJTableInsert {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
final DefaultTableModel model = new DefaultTableModel(0, 1);
new Timer(500, new ActionListener() {
private final Random random = new Random();
private int data = 1;
#Override
public void actionPerformed(ActionEvent e) {
model.insertRow(random.nextInt(model.getRowCount() + 1),
new Object[] { data++ });
}
}).start();
final JTable table = new JTable(model);
JPopupMenu popup = new JPopupMenu();
popup.add(new AbstractAction("Which row is this?") {
#Override
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(table,
"This is row " + table.getValueAt(table.getSelectedRow(), 0));
}
});
table.setComponentPopupMenu(popup);
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(new JScrollPane(table));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
model example isn't something what can be done easily here.
Here's a starter to demonstrate that the selection is kept constant (in the sense that it always points to the same "real" row:
final DefaultTableModel model = new DefaultTableModel(0, 1);
for (int i = 0; i < 50; i++) {
model.addRow(new Object[] {i});
};
final JXTable table = new JXTable(model);
table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
table.setRowSelectionInterval(25, 25);
Action l = new AbstractAction("random insert") {
Random random = new Random();
#Override
public void actionPerformed(ActionEvent e) {
int row = random.nextInt(model.getRowCount());
model.insertRow(row, new Object[] {"inserted at: " + row});
table.scrollRowToVisible(table.getSelectedRow());
}
};
new Timer(100, l).start();