javafx TableView setSortPolicy - 如何在调用事件中获取排序列和顺序？

Question

我有一个TableView，需要在服务器端完成分页和排序。我开始使用一个简单的thread.sleep来创建一个模拟服务调用的例子。

我看到我可以创建一个页面工厂，它返回不同的页面并调用后端服务来检索页面。

我看到我可以覆盖setSortPolicy方法，当我点击对列进行排序时会调用此方法。

我不知道的是如何从TableView对象中检索，单击了哪些列以应用正确的排序并将其反映在列标题上，目前我的示例下面将始终返回相同的排序顺序而不是设置列标题。

如果有人能够纠正这个例子以正确反映排序，我将非常感激。

package example;

import javafx.application.Application;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.control.Pagination;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
import javafx.util.Callback;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

public class TestTablePagination extends Application {

private final static int dataSize = 10_023;
private final static int rowsPerPage = 1000;

private final TableView<Sample> table = createTable();
private final List<Sample> data = createData();
private Pagination pagination = null;

private List<Sample> createData() {
    List<Sample> data = new ArrayList<>(dataSize);

    for (int i = 0; i < dataSize; i++) {
        data.add(new Sample(i, "foo " + i, "bar " + i));
    }

    return data;
}

private TableView<Sample> createTable() {

    TableView<Sample> table = new TableView<>();

    TableColumn<Sample, Integer> column1 = new TableColumn<>("Id");
    column1.setCellValueFactory(param -> param.getValue().id);


    TableColumn<Sample, String> column2 = new TableColumn<>("Foo");
    column2.setCellValueFactory(param -> param.getValue().foo);


    TableColumn<Sample, String> column3 = new TableColumn<>("Bar");
    column3.setCellValueFactory(param -> param.getValue().bar);


    table.getColumns().addAll(column1, column2, column3);
    table.setColumnResizePolicy(TableView.CONSTRAINED_RESIZE_POLICY);
    return table;
}

private void simulateSlowServeSideCall() {
    try {
        Thread.sleep(500);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

private Node createPage(int pageIndex) {
    table.getItems().clear();
    table.setSortPolicy( new Callback<TableView<Sample>, Boolean>() {
        @Override
        public Boolean call(TableView<Sample> tableView) {
            System.out.println("call called - Start");
            simulateSlowServeSideCall();
            Comparator<Sample> comparator = new Comparator<Sample>() {
                @Override
                public int compare(Sample r1, Sample r2) {
                    if (tableView.getComparator() == null) {
                        return 0;
                    } else {
                        return tableView.getComparator().compare(r1, r2);
                    }
                }
            };


            int fromIndex = pagination.getCurrentPageIndex() * rowsPerPage;
            int toIndex = Math.min(fromIndex + rowsPerPage, data.size());
            System.out.println("call called - " + fromIndex + " " + toIndex);

            table.setItems(FXCollections.observableArrayList(data.subList(fromIndex, toIndex)));
            FXCollections.sort(table.getItems(), comparator);
            System.out.println("call called - Finish");
            return true;
        }
    });

    Thread thread = new Thread() {
        @Override
        public void run() {
            System.out.println("createPage called - Start");
            simulateSlowServeSideCall();
            int fromIndex = pageIndex * rowsPerPage;
            int toIndex = Math.min(fromIndex + rowsPerPage, data.size());
            table.setItems(FXCollections.observableArrayList(data.subList(fromIndex, toIndex)));
            System.out.println("createPage called - Finish");
        }
    };
    thread.start();

    return new BorderPane(table);
}

@Override
public void start(final Stage stage) throws Exception {
    pagination = new Pagination((data.size() / rowsPerPage + 1), 0);
    pagination.setPageFactory(this::createPage);

    Scene scene = new Scene(new BorderPane(pagination), 1024, 768);
    stage.setScene(scene);
    stage.setTitle("Table pager");
    stage.show();
}

public static void main(String[] args) throws Exception {
    launch(args);
}

public static class Sample {

    private final ObservableValue<Integer> id;
    private final SimpleStringProperty foo;
    private final SimpleStringProperty bar;

    private Sample(int id, String foo, String bar) {
        this.id = new SimpleObjectProperty<>(id);
        this.foo = new SimpleStringProperty(foo);
        this.bar = new SimpleStringProperty(bar);
    }
}
}