如何用 ObservableMap<KeyObject, ObservableList&-Java问题

How to fill TableView with ObservableMaplt;KeyObject, ObservableListlt;CustomObjectgt;gt; in JavaFX(如何用 ObservableMaplt;KeyObject, ObservableListlt;CustomObjectgt;gt; 填充 TableView在 JavaFX 中)

本文介绍了如何用 ObservableMap<KeyObject, ObservableList<CustomObject>> 填充 TableView在 JavaFX 中的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我的 Java 程序产生了大量数据，我用这些数据构造了单独的 ResultObject.因为只有某些 ResultsObjects 会感兴趣，所以我用我的结果填充 ObservableHashMap<>.CustomObject 由几个整数 + 双精度和一个 JSONObject 组成.有了这个CustomObject，我想将类似的ResultObjects(具有某些共同属性)映射到那个CustomObject.

My Java programm produces a lot of data, with wich I construct individual ResultObject. Because only certain ResultsObjects will be of interest, I populate an ObservableHashMap<> with my results. The CustomObject consists of a handful ints + doubles and one JSONObject. With this CustomObject I want to map similar ResultObjects(which have certain properties in common) to that one CustomObject.

虽然映射和处理这些结果按预期工作，但我几乎无法使用 ObservableHashMap<> 填充 TableView.

While mapping and handling those results works as intended, I am pretty much helpless to populate a TableView with that ObservableHashMap<>.

我的CustomObject(JSONObject只是为了检查，如果两个CustomObjects具有相同的属性):

My CustomObject (JSONObject simply to check, if two CustomObjects have the same properties):

public CustomObject(Simulation data) {

    this.datapoint1 = data.datapoint1;
    this.datapoint2 = data.datapoint2;

    this.jsonCompareObject = new JSONObject()
            .put("datapoint1", data.datapoint1)
            .put("datapoint1", data.datapoint2);
}

我的 ObservableHashMap 对象:

My ObservableHashMap Object:

private ObservableMap <CustomObject, ObservableList<Simulation>> topResultsList;

public SomeObjectWithObservableMap(){
    this.topResultsList = FXCollections.observableHashMap();
}

通过使用下面的代码，我检查是否有一个键已经存在相应的数据点，然后添加到它的 ObservableList(值):

By using the following code, I check if there is a key with the corresponding datapoints already present to then add to its ObservableList (Value):

private boolean isKeyPresent(CustomObject newCustomObject, Simulation data) {
    for (CustomObject oldCustomObject : this.topResultsList.keySet()) {
        if (oldCustomObject.jsonCompareObject.toString().equals(newCustomObject.jsonCompareObject.toString())) {
            this.topResultsList.get(oldCustomObject).add(data);
            return true;
        }
    }
    return false;
}

我像这样填充其他一些 TableView:

I populate some other TableView like this:

{
    tableColumn.setCellValueFactory(new PropertyValueFactory<>("datapoint1"));
    tableColumn.setCellFactory(TextFieldTableCell.<SomeObject, Double>forTableColumn(twoDigits));
    tableView.setItems(someObject.getObservableList());
}

最后我想要一些 TableColumns 来显示来自 CustomObject 的属性.稍后，我希望所选 CustomObject 的各个映射 ObservableLists 显示在单独的 TableView 中.

In the end I want some TableColumns to show properties from the CustomObject. Later on, I would want the individual mapped ObservableLists of a selected CustomObject to be shown in a seperate TableView.

我对 Java 和 JavaFX 还很陌生，我希望尽可能专业地描述我的问题.如果我遗漏了什么，请告诉我.

I am pretty new to Java and JavaFX and I hope to have described my problem as professional as possible. Please let me know, if I missed anything.

推荐答案

这应该适用于 List



Main.java
package tester;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.layout.HBox;
import javafx.stage.Stage;

public class Tester extends Application
{

    @Override
    public void start(Stage primaryStage)
    {

        TableView<LineItem> table = new TableView<>();
        List<Map<String, String>> databaseObject = getDatabaseObject();

        for (String key : databaseObject.get(0).keySet())
        {
            TableColumn<LineItem, String> col = new TableColumn<>(key);
            col.setCellValueFactory((TableColumn.CellDataFeatures<LineItem, String> cellData) -> cellData.getValue().fieldProperty(key));            
            table.getColumns().add(col);

        }
        List<LineItem> data = new ArrayList<>();
        LineItem sequence1 = new LineItem(databaseObject.get(0));
        LineItem sequence2 = new LineItem(databaseObject.get(1));
        data.add(sequence1);
        data.add(sequence2);

        table.setItems(FXCollections.observableArrayList(data));

        table.setPrefWidth(500);

        HBox root = new HBox();
        root.getChildren().addAll(table);

        Scene scene = new Scene(root, 500, 500);

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args)
    {
        launch(args);
    }

    private List<Map<String, String>> getDatabaseObject()
    {
        List<Map<String, String>> values = new ArrayList<>();

        Map<String, String> record1 = new HashMap<>();
        record1.put("firstName", "Joe");
        record1.put("lastName", "Blob");
        record1.put("address", "95 circle ave");
        record1.put("city", "Toronto");
        record1.put("postalCode", "L9Y4Z4");
        values.add(record1);

        Map<String, String> record2 = new HashMap<>();
        record2.put("firstName", "Sarah");
        record2.put("lastName", "Blob");
        record2.put("address", "92 main st");
        record2.put("city", "London");
        record2.put("postalCode", "T9Y4K4");
        values.add(record2);

        return values;
    }

}

LineItem.java
package tester;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;

public class LineItem
{

    private final Map<String, StringProperty> fields;

    public LineItem(Map<String, String> record)
    {
        this.fields = new HashMap<>();
        for (String key : record.keySet())
        {
            this.fields.put(key, new SimpleStringProperty());
        }
        for (Entry<String, String> entry : ((Set<Entry<String, String>>) record.entrySet()))
        {

            this.fields.get(entry.getKey()).set(entry.getValue());
        }
    }

    public final StringProperty fieldProperty(String key)
    {
        return this.fields.get(key);
    }

}


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