Question

I am trying to set column width to the length of the column name. My problem is, I am not able to set it. When I use the following code the table is becoming like this,

tableA.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
  for(int i = 0; i < tableA.getColumnCount(); i++) {
int columnLength = (modelA.getColumnName(i)).length();
tableA.getColumnModel().getColumn(i).setPreferredWidth(columnLength);
//  tableA.getColumnModel().getColumn(i).setMinWidth(columnLength);
//  tableA.getColumnModel().getColumn(i).setMaxWidth(columnLength);
  }

I am getting the column length correctly from my table model.

When I use the above code the table is getting packed like this,

I am not able to understand where I am doing wrong.

Answer 1

As Dan has pointed out, you need to calculate the actual width of the column name based on the Font that is being used.

Something like:

String name = modelA.getColumnName(i);
Font f = tableA.getFont();
FontMetrics fm = tableA.getFontMetrics(f);
int width = fm.stringWidth(name);
tableA.getColumnModel().getColumn(i).setPreferredWidth(width);

Note that this is an extremely abbreviated example.

If you want to get it completely correct, you will need to query each column’s renderer for the Font and the FontMetrics in order to get the correct values.

If all your renderers use the same font as the JTable, then this should be OK.