JTable Usage !!

Question

Hi ,
Can I insert a new column in an existed tabel ? How to hide the grid of a tabel ? For a special column , I want it just can access date format , how to do this? Thanks.
Liwei

Answer 1

You need to create a custom TableModel and give it methods to allow you to add (and indeed remove) columns. The TableModel interface has two methods
int getColumnCount()
int getRowCount()
Since your constructing your own TableModel (probably overriding AbstractTableModel), you'll have to override these two methods so that you can supply the correct current number of columns and rows.
Here's an example:
import javax.swing.table.*;
public class DynamicTableModel extends AbstractTableModel {
     private String[] columnNames;
     /** Create the dynaic table model with a list of column names*/
     public DynamicTableModel(String[] columnnames) {
          columnNames=columnnames;
     //Add a new column with a given title
     public void addNewColumn(String newColName) {
          //'Extend' the column names array and add new name to the end
          String[] newColumns = new String[columnNames.length+1];
          for (int i=0;i<columnNames.length;i++) {
               newColumns=columnNames[i];
          newColumns[columnNames.length]=newColName;
          columnNames=newColumns;
     /** Returns the contents of a cell, in this case a string*/
     public Object getValueAt(int rowIndex,int columnIndex) {
          String res=columnNames[columnIndex]+" "+Integer.toString(rowIndex);
          return res;
     /** Gets the name of the specified column*/
     public String getColumnName(int columnIndex) {
          return columnNames[columnIndex];
     /** Tells the table how many columns are in this tablemodel*/
     public int getColumnCount() {
          return columnNames.length;
     /** Normally, you'd have something in a model's code to hold the data, but here
     I'm just use fixed data to demo the whole concept*/
     public int getRowCount() {
          return 5;
To hide the grid lines, use JTable.setGridColor(Color gridColor) to the background color of the cells (say, Color.WHITE).