Hi there.
I have been working on this problem for couple of days now and seem to be getting nowhere. I am using an object of the DefaultTableModel class to display my information from vectors on a table i.e
DefaultTableModel tableModel;
Then I initialise the table model by doing the following:
Vector vColumnNames = new Vector();
Vector vData = new Vector();
tableModel = new DeafaultTableModel(vData, vColumnNames);
JTable table = new JTable(tableModel);
All this works fine for displaying the information but i am trying to make certain cells not editable.
I tryed the following code but it kept giving me an NullPointerException error on line 20 where it states "return vData.size()". By the way this is an inner class and I changed the code in the outer class to:
MyTableModel mtm = new MyTableModel();
JTable table = new JTable(mtm);
class MyTableModel extends DefaultTableModel{
Vector vColumnNames;
Vector vData;
public MyTableModel(){
vColumnNames = new Vector();
vData = new Vector();
vColumnNames.addElement("Product");
vColumnNames.addElement("Quantity");
vColumnNames.addElement("Total");
vData.addElement("Hello1");
vData.addElement("Hello2");
vData.addElement("Hello3");
}
public int getRowCount() {
return vData.size(); //The Error occusr here
}
public int getColumnCount() {
return vColumnNames.size();
}
public
String getColumnName(int col) {
return (String)vColumnNames.elementAt(col);
}
public Class getColumnClass(int c) {
return getValueAt(0, c).getClass();
}
public Object getValueAt(int rowIndex, int columnIndex) {
return vData.elementAt(rowIndex);
}
public boolean isCellEditable(int row, int col) {
if (row == 0 && col == 0 || row == 0 && col == 1) {
return true;
}if(row == 0 && col == 2){
return false;
}else {
return false;
}
}
public void setValueAt(Object value, int row, int col) {
if (DEBUG) {
System.out.println("Setting value at " + row + "," + col
+ " to " + value
+ " (an instance of "
+ value.getClass() + ")");
}
vData.setElementAt(value, row);
fireTableCellUpdated(row, col);
if (DEBUG) {
System.out.println("New value of data:");
printDebugData();
}
}
private void printDebugData() {
int numRows = getRowCount();
int numCols = getColumnCount();
for (int i=0; i < numRows; i++) {
System.out.print(" row " + i + ":");
for (int j=0; j < numCols; j++) {
//System.out.print(" " + oData[i][j]);
}
System.out.println();
}
System.out.println("--------------------------");
}
}
Sorry for posting so much code. Thanks in advacnce for any help.
