import javax.swing.JTable;
import javax.swing.table.TableColumn;
public class Main {
public static void main(String[] argv) {
int rows = 3;
int cols = 3;
JTable table = new JTable(rows, cols);
//
table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
TableColumn col = table.getColumnModel().getColumn(0);
int width = 100;
col.setPreferredWidth(width);
}
}