How can I resize a JTable's column width?

[gajo]

Hi,
I've created a JTable and filled it out with some data, but by default the
table's header is filled out by values like A,B,C,... So I've created a new
JTableHeader which is wrapped around a DefaultTableColumnModel object that
I've created and to which I have added the neccessary columns and set their
size and text.
After I start the application, the header of the table looks good, but the
table columns do not follow the header's column's width. That is, the width
of the header's columns are not equals to the table's.
I tried to make the table's column model the same as the header's, by doing
table.setColumnModel(myColumns); but instead of getting what I wanted I've
got an empty table (the values I entered did not show up), and all the
column widths were equal and set to some default value. I could tollerate
even that, but why don't the cell values show up? I tried revalidating,
repainting and doLayout(), but nothing works.

So what should I do to customize the table's column width to be equal to
that of the headers?
And btw. how can I add a scrollbar to the table? Wrapping a ScrollPane
around it doesn't seem to work!

Here's some code for further explanation, just in case:
// I create the table
myTable = new JTable(numRows, 3);

// I create the column model
TableColumn firstCol = new TableColumn();
firstCol.setHeaderValue("Red");
firstCol.setWidth(50);
TableColumn secondCol = new TableColumn();
secondCol.setHeaderValue("Blue");
secondCol.setWidth(80);
TableColumn thirdCol = new TableColumn();
thirdCol.setHeaderValue("Brown");
thirdCol.setWidth(40);

DefaultTableColumnModel myCols= new DefaultTableColumnModel();
myCols.addColumn(firstCol);
myCols.addColumn(secondCol);
myCols.addColumn(thirdCol);

// I set the table's header
myTable.setTableHeader(new JTableHeader(myCols));

// if I do this the cell values won't show
// myTable.setColumnModel(myCols);

// I add the data to the cells
for (int i = 0; i<numRows; i++) {
myTable.setValueAt("bear", i, 0);
myTable.setValueAt("fox", i, 0);
myTable.setValueAt("pheasant", i, 0);
}

 

[VisionSet]

Hi,
I've created a JTable and filled it out with some data, but by default the
table's header is filled out by values like A,B,C,... So I've created a new
JTableHeader which is wrapped around a DefaultTableColumnModel object that
I've created and to which I have added the neccessary columns and set their
size and text.

The usual simple approach is to sublclass AbstractTableModel and override
getComumnName(int index);

However, the same model object should be used for both header and table.

 

[Pacific Guy]

Hi,
I've created a JTable and filled it out with some data, but by default the
table's header is filled out by values like A,B,C,... So I've created a new
JTableHeader which is wrapped around a DefaultTableColumnModel object that
I've created and to which I have added the neccessary columns and set their
size and text.
After I start the application, the header of the table looks good, but the
table columns do not follow the header's column's width. That is, the width
of the header's columns are not equals to the table's.
I tried to make the table's column model the same as the header's, by doing
table.setColumnModel(myColumns); but instead of getting what I wanted I've
got an empty table (the values I entered did not show up), and all the
column widths were equal and set to some default value. I could tollerate
even that, but why don't the cell values show up? I tried revalidating,
repainting and doLayout(), but nothing works.

So what should I do to customize the table's column width to be equal to
that of the headers?
And btw. how can I add a scrollbar to the table? Wrapping a ScrollPane
around it doesn't seem to work!

I'm not sure what you're using as the datamodel for your table, but if
you're using a custom object as opposed to a simple array, implement
it's public String getColumnName(int idx){} method to return the
correct column name. If you do that the JTable will output the correct
column header names and your column header widths will stay synched up
with the widths of the table columns.

If you are using simple arrays, follow the constructor example at the
top of this tutorial to display column headers with simple data from
arrays:

http://java.sun.com/docs/books/tutorial/uiswing/components/table.html