如何保留primefaces数据表的排序顺序？

private List<MyData> myDataList;

public MyBean() {
    myDataList = new ArrayList<>();
    // 填充数据
}

public void sortData(SortEvent event) {
    String sortColumn = event.getSortColumn();
    SortOrder sortOrder = event.getSortOrder();

    if (sortOrder.equals(SortOrder.ASCENDING)) {
        myDataList.sort(Comparator.comparing(MyData::getSortColumn));
    } else {
        myDataList.sort(Comparator.comparing(MyData::getSortColumn).reversed());
    }
}

<p:dataTable value="#{myBean.myDataList}" var="data">
    <p:column headerText="Column 1" sortBy="#{data.column1}">
        <h:outputText value="#{data.column1}" />
    </p:column>
    <p:column headerText="Column 2" sortBy="#{data.column2}">
        <h:outputText value="#{data.column2}" />
    </p:column>
    <p:ajax event="sort" listener="#{myBean.sortData}" update="@this" />
</p:dataTable>