JTable column resize dilemma?

Hi:
I have a JTable instance jTable resides in a JScrollPane that loads data from a file. However the horizontal scroll bar does not come out even if there are way too many columns. I searched online and find out I have to do this:
jTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
Now I have another problem. Every column are the same size, even if some column clearly have longer string.
Sure I can write an algorithm calculating suitable column width, but, is there a better way? I mean JTable's auto resizing algorithm clearly know which column should be wider but it is just a little stupid for trying to squeeze everything in a tiny space even though there is a horizontal scroll bar...
Can't we let the JTable figure out the right width without the width constraint?
thanks

Can't we let the JTable figure out the right width without the width constraint?There are solutions in the forum for dynamically determining the width of a column.

Similar Messages

Jtable column resize

Hi all!
i'm using:
jTable1.getColumnModel().getColumn(1).setPreferredWidth(7);
to resize jtable column width but it's not working, do you know what can be happening?
thanks!

All you've done is say what size you would prefer.
You then have to force the component to repaint, with something like
            jTable1.invalidate();
            jTable1.doLayout();
            jTable1.repaint();Ps. I posted a nice utility class to automaticaly fit the JTable columns to the exact size required here.
http://forum.java.sun.com/thread.jspa?forumID=54&messageID=2532529&threadID=527301
regards,
Owen

JTable column resize listener

Hi friends !
I want to trap the event when user resizes the width of any column. Which listener will help me for this.
Thanks in advance.
Ramesh

Thanks a lot camickr !!
It worked fine !! I did it like this
table.getColumnModel().addColumnModelListener(new TableColumnModelListener(){
     public void columnMarginChanged(ChangeEvent e)
               // Your code goes here..
     public void columnSelectionChanged(ListSelectionEvent e){}
     public void columnAdded(TableColumnModelEvent e){}
     public void columnMoved(TableColumnModelEvent e){}
     public void columnRemoved(TableColumnModelEvent e){}
});Thanks a lot again !!

Resize JTable Columns without Column Header

Hi all.
I have a JTable that doesn't display a column header.
I would like to allow the user to resize the columns by dragging a mouse at the column edges at any point down the table.
It is not obvious how I can accomplish this.
Does anyone have any ideas?
Thanks, Paul.

That doesn't work, though, since the table has its own listenersIt's not just that. The header's mouse listeners work with instance fields of BasicTableHeaderUI and detection (using e.getPoint) of the header cell and column.
I would start with copying the entire code of BasicTableHeaderUI to a class of my own, then first eliminate anything that obviously isn't related to column dragging/resizing, then refactor, refactor, refactor to make the listener codes work with a table instead of a header. But like I said, easier said than done, particularly when having to deal with the various JTable column resize modes.
db

JTable in JPanel last Column resize clips JTable doesnt repaint JPanel

I have a JTable in a JPanel, when I drag the last column of the JTableHeader (u can see the column resizing as the text of the Table HeaderColumn moves with the drag) the JTable is outside the JPanel. Only when u click on another component and then click back on the JTableHeader does it repaint.
I have tried jPanel.revalidate(); in the mouseDragged event of MouseMotionListener on the JTableHeader and all manner or repaints and fireTableStructureChanged. But I dont understand the order of events.
The last bug to fix!!!
NB I dont want to use scrollpane as its not necessary and as many tables are synchronized with one table it makes repaints less smooth
Thanks Paul

Well, I didn't find an answer but I did find a solution.
The JPanel is the problem. I use it to help with layout which is not obvious in this example.
As you can see in the code the JTable is placed in a JScrollPane which is place in a JPanel which is placed in a JTabbedPane.
If I use Box instead of JPanel the JTable in the JScrollPane in the Box in the TabbedPane in the JFrame resizes correclty.
So although JPanel is resizable with setSize it does not get resized when it's JFrame gets resized.
I would still like to know why?
////////KBS
JTabbedPane myTP = new JTabbedPane();
Box myOne = Box.createHorizontalBox();
Box myTwo = Box.createHorizontalBox();
myOne.add(pane);
myTP.add("One", myOne);
myTP.add("Two", myTwo);
////////KBS

Resize JTable columns by double-clicking header

I want to implement column resizing in a JTable so that when the user double clicks on the column header with the mouse in the "resize zone" the column automatically adjusts to the width of the longest text in the column. this is how many applications behave (e.g. windows explorer) but I don't think I've ever seen a swing app that does this. I've looked in the API docs for JTable and JTableHeader and I can't see any way of finding out if the mouse is over the edge of a column header. does anyone know of a way to do this?

Is this laf independant?import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
public class Test extends JFrame {
public Test() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container content = getContentPane();
    String[] head = {"One","Two","Three"};
    String[][] data = {{"R1-C1","R1-C2","R1-C3"},
            {"R2-C1","R2-C2","R2-C3"},
            {"R3-C1","R3-C2","R3-C3"}};
    JTable jt = new JTable(data, head);
    JScrollPane jsp = new JScrollPane(jt);
    content.add(jsp, BorderLayout.CENTER);
    JTableHeader jth = jt.getTableHeader();
    jth.addMouseListener(new MouseAdapter() {
      public void mouseClicked(MouseEvent me) {
        JTableHeader jth = (JTableHeader)me.getSource();
        int col = jth.columnAtPoint(me.getPoint());
        Rectangle r = jth.getHeaderRect(col);
        if (jth.getCursor().equals(Cursor.getPredefinedCursor(Cursor.E_RESIZE_CURSOR))) {
          System.out.println("Cursor, col="+col);
    setSize(300, 300);
    setVisible(true);
public static void main(String args[]) { new Test(); }
}

What method should be used for resizing the particular JTable Column width

I have a four table. Only one table which are on top have a table header. I want that when user resize the topmost table with a mouse other table colume also be resized automatically. So I want to know that what method should be used for resizing the particular JTable Column width.
Thanks
Lalit

maybe you can implement a interface ComponentListener as well as ComponentAdapter with your topmost Table.
for example:
toptable.addComponentListener(
new ComponentAdapter(){
public void componentResized(ComponentEvent e){
table1.setSize(....);
table2.setSize(....);
/*Optionally, you must also call function revalidate
anywhere;*/
);

User cannot resize jTables� columns

Hello,
Using NetBeans IDE 3.5.1, I built a jTable, controlled by a
JScrollpane.
My problem is that the user cannot resize the jTables� columns.
Maximum details:
1.     jtablewidth is set to a fixed value according to internal data:
JTable1.setPreferredSize( new Dimension(tableWidth, i_TableHeight));
2.     columnwidth is set according to internal data:
Col = JTable1.getColumnModel().getColumn(i);
Col.setWidth(width);
Col.setResizable(true);
Col.setMinWidth(width);
3.     jTable header details:
JTableHeader anHeader = JTable1.getTableHeader();
anHeader.setReorderingAllowed(false);
anHeader.setResizingAllowed(true);
4.     JTable1.getTableHeader().setResizingAllowed(true);.
5.     Initial declerations:
a.     JTable1.setAutoResizeMode(javax.swing.JTable.AUTO_RESIZE_OFF);
     JTable1.setColumnSelectionAllowed(true);
     JTable1.setDragEnabled(true);
     JTable1.setPreferredScrollableViewportSize(new
java.awt.Dimension(650, 500));
     JTable1.setPreferredSize(new java.awt.Dimension(1200, 409));
     JTable1.setRequestFocusEnabled(false);
b.     JScrollPane1.setMaximumSize(new java.awt.Dimension(750, 412));
     JScrollPane1.setPreferredSize(new java.awt.Dimension(750,
412));
     JScrollPane1.setViewportView(JTable1);
     JScrollPane1.setAutoScolls(false);
c.     Jtable.autoCreateColumnsFromModel (true);
Thanks alot,
Itay

Columns resizing works by default. You don't need to do anything special.
If you need further help then you need to create a [url http://homepage1.nifty.com/algafield/sscce.html]Short, Self Contained, Compilable and Executable, Example Program that demonstrates the incorrect behaviour, because I can't guess exactly what you are doing based on the information provided.
And don't forget to use the [url http://forum.java.sun.com/help.jspa?sec=formatting]Code Formatting Tags so the code retains its original formatting.

How to resizea JTable column to fit to text programatically?

hi evreyone,
i'm trying to resize a JTable column width to fit to the contained text programatically.my approach was that i made a comparison between the length of String objects contained in my column and got the biggest String length value but i want to know how can i resize the column to fit to this biggest String object

You're going the wrong way about it - don't go calculating string lengths. Get the TableCellRenderer, query it for the renderer component for each cell in the column, obtain its preferred size and keep a record of the greatest width value.

JTable: resizing all columns as 1 column resizes

I have a JTable with 480 columns inside of a JScrollPane (AUTO_RESIZE_ALL_COLUMNS needs to be off for the JTABLE to display correctly in the JScrollPane). When the user resizes one column I would like the rest of the columns to resize too, so that the column widths of each column are equal.
Thank you in advance,
Brent

[...] I
I have the JScrollPane listening to a histogram of the
balances so the user can click on a month in the
histogram and the JScrollPane (actually JViewport)
will move to display the appropriate column in the
JTable. If the column sizes are not uniform then I
cannot be sure that I'm moving the JViewport to
display the correct JTable column(s).
I thing the GUI is a great design for what must be
done. And thank you for your help and comments.That still sounds pretty klunky. I don't see any user navigating around a 480 column table. They click in your histogram to go to a column, they click somewhere or do keyboard navigation and the display scrolls them a few columns/rows away... they are now lost in a sea of cells and have to go back to the histogram again to try and get back, etc. Having delt with similar situations, there are better ways. Read the last two days dilbert cartoons carefully. :-)
But anyway...
You don't have to have all the columns the same width to make a column visible in the viewport. You can just get the appropriate column's rect by either of these methods:Rectangle r = myTable.getTableHeader().getHeaderRect( col );
Rectangle r = myTable.getCellRect( row, col, true );And then tell the viewport to make sure that rect is visible:myViewport.scrollRectToVisible( r );Much easier than hacking around with custom column resizing logic.

JTable Header resizing codes ?

Does anyone have reusable codes that can accept the column names then resize the JTable columns automatically. By using the column names width the table headers are automatically computed to column preferred size.

Please refer to http://www2.gol.com/users/tame/swing/examples/SwingExamples.html for a possible solution.

JTable column auto-maximum width

Hi,
Does anyone have an idea on how to make the JTable to support column auto-maximum width resize, like we always see in a microsoft's table component, you double click on the column seperater and the column resized to its maximum size according to the content in it.
Thanks
Yutong

Hi again,
I wrote two methods to solve this kind of problem... take a look at them and tell me what you think about it...
   /** Adjusts the widths of a JTable columns
    * @param table    the table
   public static void resizeTableColumns(JTable table) {
      table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
      TableColumn c = null;
      FontMetrics fm = table.getFontMetrics(table.getFont());
      for (int i=0; i<table.getColumnCount(); i++) {
         c = table.getColumn(table.getColumnName(i));
         c.setPreferredWidth(determineColumnWidth(c, table.getModel(), fm));
   /** Returns the preferred width of a JTable column. The resulting width
    * is 5 pixels wider than the biggest column
    * @param col    the column
    * @param model the table model
    * @param fm     the font metrics
    public static int determineColumnWidth(TableColumn col, TableModel model,
                                          FontMetrics fm) {
      String value = (String)col.getHeaderValue();
      int headerWidth = fm.stringWidth("." + value.trim() + ".");
      int columnNumber = col.getModelIndex();
      int max = headerWidth;
      int columnWidth = 0;
      int nrows = model.getRowCount();
      String cell = "";
      for (int i=0; i<nrows; i++) {
         value = (String)model.getValueAt(i, columnNumber);
         columnWidth = fm.stringWidth("." + value.trim() + ".");
         if (columnWidth > max) max = columnWidth;
      return max + 5;

JTable Column Resizig Event

Hi
Can anyone tell the event that is fired when the column of a jtable is resized
rgrds
sharmila

This is just a guess
I have not tried it out
Try addPropertyChangeListener() of class javax.swing.table.TableColumn
and in that as the size changes for that write appropriate code
CSJakharia

Help with JTable column width

Hi,
I'm trying to resize my JTable columns with this code, but it's not working. What I am doing wrong?
for (int i = 0; i < table.getColumnModel().getColumnCount(); i++) {
TableColumn tc = table.getColumnModel().getColumn(i);
int width = (i == 0)? 10 : table.getWidth()/2 - 10; // three columns
tc.setPreferredWidth(width);
Thanks,
Andr�

Now my problem is that using either of these methods
is they don't carry the user's selected column width
through updates.It sounds like the change event your table model is firing is causing the entire table to be rebuilt. I would guess that you are firing fireTableStructureChanged() which would cause the entire table to be rebuilt (columns, cell values, etc.) Just fire a change event for the minimum necessary. If you can't identify what data in your table has changed (to fire cell or row change events), but the structure (columns) of the table hasn't changed, just fire fireTableDataChanged(). This will cause the cells to be redrawn with the new values, but shouldn't cause the columns to be rebuilt and resized.

How Can I set up a JTable columns?

Dear All,
How can I set up my JTable columns to have the amount the user specifies?
for example when the user types in 50 in JTextField 1 I want the JTables columns to then set to 50.
How can this be done?
Thanks
lol
import javax.swing.*;
import javax.swing.table.TableModel;
import java.io.*;
import java.util.*;
import java.lang.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class si1 extends javax.swing.JFrame implements ActionListener {
    JTextField name = new JTextField(15);
    JTextField name1 = new JTextField(15);
    public si1() {
        super("DataBase Loader");
        setSize(1025,740);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel pane = new JPanel();
        JPanel pane1 = new JPanel();
        JPanel pane2 = new JPanel();
        JPanel pane3 = new JPanel();
        JPanel pane4 = new JPanel();
        pane.setLayout(new GridLayout(20,1));
        pane1.setLayout(new BorderLayout());
        int j=10;
        String[][] data = new String[j][2];
        for (int k=0; k<j; k++){
           String[] row = {"",""};
           data[k] = row;
        String[] columnNames = {"First Name", "Last Name"};
        JTable perstab = new JTable(data, columnNames);
        perstab.setGridColor(Color.yellow);
        perstab.setPreferredScrollableViewportSize(new Dimension(500,500));
        JScrollPane scrollPane = new JScrollPane(perstab);
        pane1.add(new JPanel(), BorderLayout.EAST);
        JButton btn = new JButton("What are the names?");
        btn.addActionListener(this);
        btn.putClientProperty("DATABASE", perstab);
        pane1.add(new JPanel().add(btn), BorderLayout.SOUTH);
        pane2.add(name);
        pane3.add(name1);
        pane.add(pane2);
        pane.add(pane3);
        pane1.add(pane, BorderLayout.WEST);
        pane4.add(scrollPane);
        pane1.add(pane4, BorderLayout.CENTER);
        setContentPane(pane1);
        show();
    public static void main(String[] args) {
        si1 frame = new si1();
        frame.setVisible(true);
    public void actionPerformed(ActionEvent e) {
        JTable table = (JTable)((JButton)e.getSource()).getClientProperty("DATABASE");
        TableModel model = table.getModel();
        int count = model.getRowCount();
        String[] firstnames = new String[count];
        String[] lastnames = new String[count];
        for (int i=0; i < count; i++) {
           firstnames[i] = (String)model.getValueAt(i, 0);
            System.out.println("first name at row " + i + ": " + firstnames);
lastnames[i] = (String)model.getValueAt(i, 1);
System.out.println("lastname name at row " + i + ": " + lastnames[i]);

As you can see I have tried this, but no success.
If I am doing something wrong please accept my apology, and address me in the right direction.
Thanks
Lol
import javax.swing.*;
import javax.swing.table.TableModel;
import java.io.*;
import java.util.*;
import java.lang.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class si1 extends javax.swing.JFrame implements ActionListener {
    JTextField name = new JTextField(15);
    JTextField name1 = new JTextField(15);
    public si1() {
        super("DataBase Loader");
        setSize(1025,740);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel pane = new JPanel();
        JPanel pane1 = new JPanel();
        JPanel pane2 = new JPanel();
        JPanel pane3 = new JPanel();
        JPanel pane4 = new JPanel();
        pane.setLayout(new GridLayout(20,1));
        pane1.setLayout(new BorderLayout());
        int j=10;
        String[][] data = new String[j][2];
        for (int k=0; k<j; k++){
           String[] row = {"",""};
           data[k] = row;
        String[] columnNames = {"First Name", "Last Name"};
        JTable perstab = new JTable(data, columnNames);
     ((DefaultTableModel)perstab.getModel()).setColumnCount(Integer.parseInt(name.getText()));
        perstab.setGridColor(Color.yellow);
        perstab.setPreferredScrollableViewportSize(new Dimension(500,500));
        JScrollPane scrollPane = new JScrollPane(perstab);
        pane1.add(new JPanel(), BorderLayout.EAST);
        JButton btn = new JButton("What are the names?");
        btn.addActionListener(this);
        btn.putClientProperty("DATABASE", perstab);
        pane1.add(new JPanel().add(btn), BorderLayout.SOUTH);
        pane2.add(name);
        pane3.add(name1);
        pane.add(pane2);
        pane.add(pane3);
        pane1.add(pane, BorderLayout.WEST);
        pane4.add(scrollPane);
        pane1.add(pane4, BorderLayout.CENTER);
        setContentPane(pane1);
        show();
    public static void main(String[] args) {
        si1 frame = new si1();
        frame.setVisible(true);
    public void actionPerformed(ActionEvent e) {
        JTable table = (JTable)((JButton)e.getSource()).getClientProperty("DATABASE");
        TableModel model = table.getModel();
        int count = model.getRowCount();
        String[] firstnames = new String[count];
        String[] lastnames = new String[count];
        for (int i=0; i < count; i++) {
           firstnames[i] = (String)model.getValueAt(i, 0);
            System.out.println("first name at row " + i + ": " + firstnames);
lastnames[i] = (String)model.getValueAt(i, 1);
System.out.println("lastname name at row " + i + ": " + lastnames[i]);

JTable column resize dilemma?

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