Jtable doesn't refresh/update data

Question

I have a problem with JTable/JScrollPane. My data table is not refreshing/updating. I am using DefultTableModel and according to the c

Answer 1

From what I understand from the comments and the question, you have first created a DefaultTableModel by passing the data as arrays in the constructor

String[][] data = new String[100][4];
String[] columnNames = new String[]{
     "IP", "PC_NAME", "ttl", "db"};
DefaultTableModel model = new DefaultTableModel(data,columnNames);

and you try to modify the table afterwards by adjusting those arrays. That will never ever have any effect, as the DefaultTableModel does not use those arrays. This can be seen in the source code of that class

public DefaultTableModel(Object[][] data, Object[] columnNames) {
    setDataVector(data, columnNames);
}

which in the end comes down to

protected static Vector convertToVector(Object[][] anArray) {
    if (anArray == null) {
        return null;
    }
    Vector v = new Vector(anArray.length);
    for (Object[] o : anArray) {
        v.addElement(convertToVector(o));
    }
    return v;
}

So all the elements of the array are copied into an internal Vector and the array is no longer used.

Solution: do not update the arrays but update the DefaultTableModel. That class provides all the API you need to add/remove data to/from it.