How to clear contents of a jTable ?

You have a couple of options:

1. Create a new DefaultTableModel(), but remember to re-attach any listeners.
2. Iterate over the model.removeRow(index) to remove.
3. Define your own model that wraps a List/Set and expose the clear method.

If you mean to remove the content but its cells remain intact, then:

public static void clearTable(final JTable table) {
   for (int i = 0; i < table.getRowCount(); i++) {
      for(int j = 0; j < table.getColumnCount(); j++) {
          table.setValueAt("", i, j);
      }
   }
}

OK, if you mean to remove all the cells but maintain its headers:

public static void deleteAllRows(final DefaultTableModel model) {
    for( int i = model.getRowCount() - 1; i >= 0; i-- ) {
        model.removeRow(i);
    }
}

Easiest way:

//private TableModel dataModel;
private DefaultTableModel dataModel;


void setModel() {
  Vector data = makeData();
  Vector columns = makeColumns();
  dataModel = new DefaultTableModel(data, columns);
  table.setModel(dataModel);
}

void reset() {
  dataModel.setRowCount(0);
}

i.e. your reset method tell the model to have 0 rows of data The model will fire the appropriate data change events to the table which will rebuild itself.

    //To clear the Contents of Java JTable

    DefaultTableModel dm = (DefaultTableModel) JTable1.getModel();

    for (int i = 0; i < dm.getRowCount(); i++) {
        for (int j = 0; j < dm.getColumnCount(); j++) {
            dm.setValueAt("", i, j);
        }
    }