Sorting rows by columns in JTable

Question

When you click the column header on my JTable, its sorts the rows alphabetically. This works for all of my columns except for one. In this column the values are all Strings,

Answer 1

please read tutorial about JTable that's contains TableRowSorter example,

your answer is these codes lines, set column Class correctly

public Class getColumnClass(int c) {
   return getValueAt(0, c).getClass();
}

// or could be in most cases hardcoded, and I'm using that too

            @Override
            public Class getColumnClass(int colNum) {
                switch (colNum) {
                    case 0:
                        return Integer.class;
                    case 1:
                        return Double.class;
                    case 2:
                        return Long.class;
                    case 3:
                        return Boolean.class;
                    case 4:
                        return String.class;
                    case 5:
                        return Icon.class;
                    /*case 6:
                    return Double.class;
                    case 7:
                    return Double.class;
                    case 8:
                    return Double.class;*/
                    default:
                        return String.class;
                }
            }