TableRowSorter<ReadOnlyTableModel> rowSorter = new TableRowSorter<>(model);
table.setRowSorter(rowSorter);        
...
private void filter(String search) {
        if (search == null || search.trim().length() == 0) {
            rowSorter.setRowFilter(null);
        } else {
            RowFilter<ReadOnlyTableModel, Integer> filter = new RowFilter<ReadOnlyTableModel, Integer>() {
                @Override
                public boolean include(RowFilter.Entry<? extends ReadOnlyTableModel, ? extends Integer> entry) {
                    String f = TextUtils.escapeMetaCharacters(search).toLowerCase();
                    for (int i = entry.getValueCount() - 1; i >= 0; i--) {
                        if (entry.getStringValue(i).toLowerCase().contains(f)) {
                            return true;
                        }
                    }
                    return false;
                }
            };
            rowSorter.setRowFilter(filter);
        }
    }

Exception in thread "Thread-5" java.lang.NullPointerException
	at java.lang.Class.isAssignableFrom(Native Method)
	at javax.swing.table.TableRowSorter.useToString(TableRowSorter.java:245)
	at javax.swing.DefaultRowSorter.updateUseToString(DefaultRowSorter.java:624)
	at javax.swing.DefaultRowSorter.sort(DefaultRowSorter.java:573)
	at javax.swing.DefaultRowSorter.setRowFilter(DefaultRowSorter.java:424)
	at com.kuazot.ciska.gui.inputs.ListBoxInputDialog.filter(ListBoxInputDialog.java:452)
        ...