Tables - The Definitive Guide to Java Swing - page 686

public Class getColumnClass(int column) {
return (getValueAt(0, column).getClass());
}
DefaultTableModel Class
The DefaultTableModel is a subclass of AbstractTableModel that provides its own Vector data
structure for storage. Everything in the data model is stored within vectors internally, even
when the data is initially part of an array. In other words, if you already have your data in an
adequate data structure, don't use DefaultTableModel . Create an AbstractTableModel that uses
the structure, instead of having a DefaultTableModel convert the structure for you.
Creating a DefaultTableModel
There are six constructors for DefaultTableModel :
public DefaultTableModel()
TableModel model = new DefaultTableModel()
public DefaultTableModel(int rows, int columns)
TableModel model = new DefaultTableModel(2, 3)
public DefaultTableModel(Object rowData[][], Object columnNames[])
Object rowData[][] = {{"Row1-Column1", "Row1-Column2", "Row1-Column3"},
{"Row2-Column1", "Row2-Column2", "Row2-Column3"}};
Object columnNames[] = {"Column One", "Column Two", "Column Three"};
TableModel model = new DefaultTableModel(rowData, columnNames);
public DefaultTableModel(Vector rowData, Vector columnNames)
Vector rowOne = new Vector();
rowOne.addElement("Row1-Column1");
rowOne.addElement("Row1-Column2");
rowOne.addElement("Row1-Column3");
Vector rowTwo = new Vector();
rowTwo.addElement("Row2-Column1");
rowTwo.addElement("Row2-Column2");
rowTwo.addElement("Row2-Column3");
Vector rowData = new Vector();
rowData.addElement(rowOne);
rowData.addElement(rowTwo);
Vector columnNames = new Vector();
columnNames.addElement("Column One");
columnNames.addElement("Column Two");
columnNames.addElement("Column Three");
TableModel model = new DefaultTableModel(rowData, columnNames);