我有一个包含ModelItem项目的主/详细面板。每个ModelItem都有一个ListProperty<ModelItemDetail>，每个ModelItemDetail都有一些StringProperty。
在详细信息面板中，我希望显示一个Label，其文字的边界将与当前所选ModelItemDetail的每个ModelItem的属性相关联。最终值可能取决于其他外部属性，例如选择了“详细信息”面板上的CheckBox（即，如果选中该复选框，则bProperty的值不包括在结果中）
此绑定使用Bindings.createStringBinding()完成了我想要的内容：
ObservableValue<ModelItem> selectedItemBinding = EasyBind.monadic(mdModel.selectedItemProperty()).orElse(new ModelItem());
// API Label Binding
apiLabel.textProperty().bind(Bindings.createStringBinding(
() -> selectedItemBinding.getValue().getDetails().stream()
.map(i -> derivedBinding(i.aProperty(), i.bProperty()))
.map(v->v.getValue())
.collect(Collectors.joining(", "))
, mdModel.selectedItemProperty(), checkBox.selectedProperty()));
例如：
private ObservableValue<String> derivedBinding(ObservableValue<String> aProp, ObservableValue<String> bProp) {
return EasyBind.combine(aProp, bProp, checkBox.selectedProperty(),
(a, b, s) -> Boolean.TRUE.equals(s) ? new String(a + " <" + b + ">") : a);
}
我最近发现了EasyBind，我试图用它替换一些API Bindings。我找不到用EasyBind表达这种绑定的方法。显然，我的代码的主要问题是因为selectedItem是一个属性，我不能将其详细信息用作ObservableList，我必须坚持使用ObservableValue<ObservableList>>。通过EasyBind.map(ObservableList)和EasyBind.combine(ObservableList)链接转换很不方便，这似乎是实现此绑定的理想候选者。在某些时候，我想过创建一个本地ListProperty并通过selectedItem上的一个监听器将它绑定到selectedItem的细节，但它看起来太冗长和不洁净。
我尝试过像这样强制使用EasyBind API：
ObservableValue<ObservableList<ModelItemDetail>> ebDetailList = EasyBind.select(selectedItemBinding).selectObject(ModelItem::detailsProperty);
MonadicObservableValue<ObservableList<ObservableValue<String>>> ebDerivedList = EasyBind.monadic(ebDetailList).map(x->EasyBind.map(x, i -> derivedBinding(i.aProperty(), i.bProperty())));
MonadicObservableValue<ObservableValue<String>> ebDerivedValueBinding = ebDerivedList.map(x->EasyBind.combine(x, stream -> stream.collect(Collectors.joining(", "))));
easyBindLabel.textProperty().bind(ebDerivedValueBinding.getOrElse(new ReadOnlyStringWrapper("Nothing to see here, move on")));
但我感觉最后getOrElse只是在初始化时被调用，并且在selectedItem更改时不会更新。
我也尝试过立即获取ObservableList，但不能指望其他任何空白列表：
ObservableList<ModelItemDetail> ebDetailList = EasyBind.select(selectedItemBinding).selectObject(ModelItem::detailsProperty).get();
ObservableList<ObservableValue<String>> ebDerivedList = EasyBind.map(ebDetailList, i -> derivedBinding(i.aProperty(), i.bProperty()));
ObservableValue<String> ebDerivedValueBinding = EasyBind.combine(ebDerivedList, stream -> stream.collect(Collectors.joining(", "))).orElse("Nothing to see here, move on");
easyBindLabel2.textProperty().bind(ebDerivedValueBinding);
我甚至尝试使用EasyBind.subscribe来监听selectedItem更改并重新绑定（对此不太确定但我不认为需要重新绑定，所有内容都可以执行计算）：
EasyBind.subscribe(selectedItemBinding, newValue -> {
if (newValue != null) {
ObservableList<ObservableValue<String>> l =
EasyBind.map(newValue.getDetails(),
i -> derivedBinding(i.aProperty(), i.bProperty()));
easyBindLabelSub.textProperty().bind(
EasyBind.combine(l,
strm -> strm.collect(Collectors.joining(", "))
));}});
这部分有效，实际上它正在收听复选框更改，但奇怪的是只有第一次更改。我不知道为什么（会很了解）。
如果我添加另一个 EasyBind.Subscribe来订阅checkbox.selectedProperty，它会按预期工作，但这也太冗长和不干净了。如果我自己将一个API监听器添加到selectedItemProperty并在那里执行绑定，也会发生同样的情况。
我使用EasyBind来表达这种绑定的动机正是摆脱了明确表达绑定依赖关系的需要，并试图进一步简化它。我提出的所有方法都明显比API更糟糕，因为我对它并不完全满意。
我仍然对JavaFX很陌生，我试图绕过这个问题。我想了解发生了什么，并找出是否有简洁而优雅的方式来表达与EasyBind的这个绑定。我开始怀疑EasyBind是否还没有为这个用例做好准备（顺便提一下，我认为这种情况很少见）。不过，可能我错过了一些微不足道的东西。
这是一个MVCE，展示了我尝试过的一些方法，以及API绑定按预期工作：
package mcve.javafx;
import java.util.*;
import java.util.stream.*;
import javafx.application.*;
import javafx.beans.binding.*;
import javafx.beans.property.*;
import javafx.beans.value.*;
import javafx.collections.*;
import javafx.scene.*;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.stage.*;
import org.fxmisc.easybind.*;
import org.fxmisc.easybind.monadic.*;
public class Main extends Application {
public static void main(String[] args) {
launch(args);
}
private CheckBox checkShowMore;
@Override
public void start(Stage primaryStage) {
try {
// Initialize model
MasterDetailModel mdModel = new MasterDetailModel();
ObservableList<ModelItem> itemsList = FXCollections.observableArrayList();
for (int i=0;i<5;i++) { itemsList.add(newModelItem(i)); }
// Master
ListView<ModelItem> listView = new ListView<ModelItem>();
listView.setItems(itemsList);
listView.setPrefHeight(150);
mdModel.selectedItemProperty().bind(listView.getSelectionModel().selectedItemProperty());
//Detail
checkShowMore = new CheckBox();
checkShowMore.setText("Show more details");
VBox detailVBox = new VBox();
Label apiLabel = new Label();
Label easyBindLabel = new Label();
Label easyBindLabel2 = new Label();
Label easyBindLabelSub = new Label();
Label easyBindLabelLis = new Label();
detailVBox.getChildren().addAll(
checkShowMore,
new TitledPane("API Binding", apiLabel),
new TitledPane("EasyBind Binding", easyBindLabel),
new TitledPane("EasyBind Binding 2", easyBindLabel2),
new TitledPane("EasyBind Subscribe", easyBindLabelSub),
new TitledPane("Listener+EasyBind Approach", easyBindLabelLis)
);
// Scene
Scene scene = new Scene(new VBox(listView, detailVBox),400,400);
primaryStage.setScene(scene);
primaryStage.setTitle("JavaFX/EasyBind MVCE");
// --------------------------
// -------- BINDINGS --------
// --------------------------
ObservableValue<ModelItem> selectedItemBinding = EasyBind.monadic(mdModel.selectedItemProperty()).orElse(new ModelItem());
// API Label Binding
apiLabel.textProperty().bind(Bindings.createStringBinding(
() -> selectedItemBinding.getValue().getDetails().stream()
.map(i -> derivedBinding(i.aProperty(), i.bProperty()))
.map(v->v.getValue())
.collect(Collectors.joining(", "))
, mdModel.selectedItemProperty(), checkShowMore.selectedProperty()));
// EasyBind Binding Approach 1
{
ObservableValue<ObservableList<ModelItemDetail>> ebDetailList = EasyBind.select(selectedItemBinding).selectObject(ModelItem::detailsProperty);
MonadicObservableValue<ObservableList<ObservableValue<String>>> ebDerivedList = EasyBind.monadic(ebDetailList).map(x->EasyBind.map(x, i -> derivedBinding(i.aProperty(), i.bProperty())));
MonadicObservableValue<ObservableValue<String>> ebDerivedValueBinding = ebDerivedList.map(x->EasyBind.combine(x, stream -> stream.collect(Collectors.joining(", "))));
easyBindLabel.textProperty().bind(ebDerivedValueBinding.getOrElse(new ReadOnlyStringWrapper("Nothing to see here, move on")));
}
// EasyBind Binding Approach 2
{
ObservableList<ModelItemDetail> ebDetailList = EasyBind.select(selectedItemBinding).selectObject(ModelItem::detailsProperty).get();
ObservableList<ObservableValue<String>> ebDerivedList = EasyBind.map(ebDetailList, i -> derivedBinding(i.aProperty(), i.bProperty()));
ObservableValue<String> ebDerivedValueBinding = EasyBind.combine(ebDerivedList, stream -> stream.collect(Collectors.joining(", "))).orElse("Nothing to see here, move on");
easyBindLabel2.textProperty().bind(ebDerivedValueBinding);
}
// Subscribe approach
EasyBind.subscribe(selectedItemBinding, newValue -> {
if (newValue != null) {
ObservableList<ObservableValue<String>> l = EasyBind.map(newValue.getDetails(), i -> derivedBinding(i.aProperty(), i.bProperty()));
easyBindLabelSub.textProperty().bind(
EasyBind.combine(l,
strm -> strm.collect(Collectors.joining(", "))
));
}
});
//With this it works as intended, but something feels very wrong about this
/*
EasyBind.subscribe(checkShowMore.selectedProperty(), newValue -> {
if (selectedItemBinding != null) {
ObservableList<ObservableValue<String>> l = EasyBind.map(selectedItemBinding.getValue().getDetails(), i -> derivedBinding(i.aProperty(), i.bProperty()));
easyBindLabelSub.textProperty().bind(
EasyBind.combine(l,
strm -> strm.collect(Collectors.joining(", "))
));
}
});
*/
// Listener approach
selectedItemBinding.addListener( (ob, o, n) -> {
ObservableList<ModelItemDetail> ebDetailList = n.getDetails();
ObservableList<ObservableValue<String>> ebDerivedList = EasyBind.map(ebDetailList, i -> derivedBinding(i.aProperty(), i.bProperty()));
ObservableValue<String> ebDerivedValueBinding = EasyBind.combine(ebDerivedList, stream -> stream.collect(Collectors.joining(", "))).orElse("Nothing to see here, move on");
easyBindLabelLis.textProperty().bind(ebDerivedValueBinding);
});
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
}
private ObservableValue<String> derivedBinding(ObservableValue<String> aProp, ObservableValue<String> bProp) {
return EasyBind.combine(aProp, bProp, checkShowMore.selectedProperty(),
(a, b, s) -> Boolean.TRUE.equals(s) ? new String(a + " <" + b + ">") : a);
}
private ModelItem newModelItem(int number) {
ModelItem item = new ModelItem();
item.itemNumber = number+1;
for (int i=0;i<2;i++) {
ModelItemDetail detail = new ModelItemDetail();
detail.setA("A" + (i+item.itemNumber));
detail.setB("B" + (i+item.itemNumber));
item.getDetails().add(detail);
}
return item;
}
/** GUI Model class */
private static class MasterDetailModel {
private ObjectProperty<ModelItem> selectedItemProperty = new SimpleObjectProperty<>();
public ObjectProperty<ModelItem> selectedItemProperty() { return selectedItemProperty; }
public ModelItem getSelectedItem() { return selectedItemProperty.getValue(); }
public void setSelectedItem(ModelItem item) { selectedItemProperty.setValue(item); }
}
/** Domain Model class */
private static class ModelItem {
int itemNumber;
private ListProperty<ModelItemDetail> detailsProperty = new SimpleListProperty<>(FXCollections.observableArrayList());
public ListProperty<ModelItemDetail> detailsProperty() { return detailsProperty; }
public ObservableList<ModelItemDetail> getDetails() { return detailsProperty.getValue(); }
public void setDetails(List<ModelItemDetail> details) { detailsProperty.setValue(FXCollections.observableList(details)); }
public String toString() { return "Item " + itemNumber; }
}
/** Domain Model class */
private static class ModelItemDetail {
private StringProperty aProperty = new SimpleStringProperty();
public StringProperty aProperty() { return aProperty; }
public String getA() { return aProperty.get(); }
public void setA(String a) { aProperty.set(a); }
private StringProperty bProperty = new SimpleStringProperty();
public StringProperty bProperty() { return bProperty; }
public String getB() { return bProperty.get(); }
public void setB(String b) { bProperty.set(b); }
}
}
更新：我取得了一些进展。
以下代码工作正常，但mysteriouysly仍然只能继续监听CheckBox上的第一个更改：
ListProperty<ModelItemDetail> obsList = new SimpleListProperty<>(FXCollections.observableArrayList(i->new Observable[] { i.aProperty(), i.bProperty(), checkShowMore.selectedProperty()}));
obsList.bind(selectedItemBinding.flatMap(ModelItem::detailsProperty));
ObservableList<ModelItemDetail> ebDetailList = obsList; // WHY ??
ObservableList<ObservableValue<String>> ebDerivedList = EasyBind.map(ebDetailList, i -> derivedBinding(i.aProperty(), i.bProperty()));
ObservableValue<String> ebDerivedValueBinding = EasyBind.combine(ebDerivedList, stream -> stream.collect(Collectors.joining(", "))).orElse("Nothing to see here, move on");
labelPlayground.textProperty().bind(ebDerivedValueBinding);
显然，我遇到麻烦的主要原因是因为我没有看到如何使用EasyBind流畅的API从绑定的当前ObservableList获取selectedItem。声明本地ListProperty并将其绑定到所选项目我可以利用ListProperty作为ObservableList。我认为EasyBind在某个地方并不适用。类型信息的感觉在某处迷路了。我无法在最后一段代码中汇总所有这些变量，而且我不明白为什么EasyBind.map（）会在最后一段代码中接受ebDetailList，但却不接受{ {1}}。
所以，现在的问题是，为什么这个绑定只是第一次收听CheckBox事件？ obsList支持列表中的提取程序不执行任何操作。我想ListProperty正在用模型中的一个替换支持列表，它没有提取器。
答案 0 :(得分：3)
如果我理解正确，您希望标签显示所选ModelItem的文字，该文字由其包含的所有ModelItemDetail组成。每当ModelItemDetail被添加或删除时，此文本都应更新，和在其a或b属性的任何ModelItemDetail或ModelItemDetail属性时更新列表已更新。
您不需要外部库来实现此1级深度绑定（a - ＆gt; b，ModelItemDetail）。 ObservableList报告对ListProperty<ModelItemDetail> detailsProperty = new SimpleListProperty<>(
FXCollections.observableArrayList(i -> new Observable[]{i.aProperty(), i.bProperty()}));
列表的更改。 extractor：
ListProperty事实上，你不需要一个ObservableList，一个简单的ModelItem就足够了。
在下面的例子中，
ListView显示在ModelItemDetail中。它初始化为3 a，其中包含b和ModelItemDetail个属性。CheckBox s。b确定是否显示b属性。请注意，即使未选中，也会继续报告对ModelItemDetail的更改（但未显示）。ObservableList添加到列表中。此更改将立即反映在a。ModelItemDetail的{{1}}属性的值。此更改将立即通过ObservableList提取程序反映出来。public class Main extends Application {
public Main() {}
public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage stage) throws Exception {
// Mock initial data
ModelItem item = new ModelItem();
ModelItemDetail mid1 = new ModelItemDetail();
mid1.setA("a1");
mid1.setB("b1");
ModelItemDetail mid2 = new ModelItemDetail();
mid2.setA("a2");
mid2.setB("b2");
ModelItemDetail mid3 = new ModelItemDetail();
mid3.setA("a3");
mid3.setB("b3");
ObservableList<ModelItemDetail> details = item.getDetails();
details.add(mid1);
details.add(mid2);
details.add(mid3);
// Create binding
CheckBox showB = new CheckBox("Show b");
Label label = new Label();
label.textProperty().bind(Bindings.createStringBinding(() -> {
return details.stream()
.map(mid ->
Boolean.TRUE.equals(showB.isSelected()) ? new String(mid.getA() + " <" + mid.getB() + ">") : mid.getA()
).collect(Collectors.joining(", "));
}, details, showB.selectedProperty()));
// Create testing components
Button add = new Button("Add item detail");
add.setOnAction(e -> {
Random r = new Random();
int i = r.nextInt(100) + 3;
ModelItemDetail mid = new ModelItemDetail();
mid.setA("a" + i);
mid.setB("b" + i);
details.add(mid);
});
Button changeA = new Button("Change some A");
changeA.setOnAction(e -> {
Random r = new Random();
ModelItemDetail detail = details.get(r.nextInt(details.size()));
detail.setA("a" + r.nextInt(100) + 3);
});
// Display everything
BorderPane pane = new BorderPane();
ListView<ModelItem> list = new ListView<>();
list.getItems().add(item);
pane.setCenter(list);
pane.setRight(new VBox(add, changeA));
pane.setTop(showB);
pane.setBottom(label);
stage.setScene(new Scene(pane));
stage.show();
}
private static class ModelItem {
int itemNumber;
private ObservableList<ModelItemDetail> detailsProperty = FXCollections.observableArrayList(i -> new Observable[]{i.aProperty(), i.bProperty()});
public ObservableList<ModelItemDetail> getDetails() { return detailsProperty; }
@Override public String toString() { return "Item " + itemNumber; }
}
/** Domain Model class */
private static class ModelItemDetail {
private StringProperty aProperty = new SimpleStringProperty();
public StringProperty aProperty() { return aProperty; }
public String getA() { return aProperty.get(); }
public void setA(String a) { aProperty.set(a); }
private StringProperty bProperty = new SimpleStringProperty();
public StringProperty bProperty() { return bProperty; }
public String getB() { return bProperty.get(); }
public void setB(String b) { bProperty.set(b); }
}
}
您可以向ModelItem添加更多ListView，并让标签显示所选标签的文字。
答案 1 :(得分：0)
经过一段时间的练习并熟悉Bindings，Properties和Observables后，我想出了我想要的东西。一个简单，功能强大，简洁且类型安全的EasyBind表达式，不需要监听器，复制或显式声明绑定依赖关系或提取器。绝对看起来比Bindings API版本要好得多。
labelWorking.textProperty().bind(
selectedItemBinding
.flatMap(ModelItem::detailsProperty)
.map(l -> derivedBinding(l))
.flatMap(l -> EasyBind.combine(
l, stream -> stream.collect(Collectors.joining(", "))))
);
用
private ObservableList<ObservableValue<String>> derivedBinding(ObservableList<ModelItemDetail> l) {
return l.stream()
.map(c -> derivedBinding(c.aProperty(), c.bProperty()))
.collect(Collectors.toCollection(FXCollections::observableArrayList));
}
Eclipse / javac中有类型推断显然存在一些错误。当我试图找到让IDE指导我的正确表达时，这无助于弄清楚事情。
为了完整起见，带有工作绑定的MVCE：package mcve.javafx;
import java.util.List;
import java.util.stream.Collectors;
import org.fxmisc.easybind.EasyBind;
import org.fxmisc.easybind.monadic.MonadicBinding;
import javafx.application.Application;
import javafx.beans.Observable;
import javafx.beans.binding.Binding;
import javafx.beans.binding.Bindings;
import javafx.beans.property.ListProperty;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleListProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.CheckBox;
import javafx.scene.control.Label;
import javafx.scene.control.ListView;
import javafx.scene.control.TitledPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class Main extends Application {
public static void main(String[] args) {
launch(args);
}
private CheckBox checkShowMore;
@Override
public void start(Stage primaryStage) {
try {
// Initialize model
MasterDetailModel mdModel = new MasterDetailModel();
ObservableList<ModelItem> itemsList = FXCollections.observableArrayList();
for (int i=0;i<5;i++) { itemsList.add(newModelItem(i)); }
MonadicBinding<ModelItem> selectedItemBinding = EasyBind.monadic(mdModel.selectedItemProperty()).orElse(new ModelItem());
// Master
ListView<ModelItem> listView = new ListView<ModelItem>();
listView.setItems(itemsList);
listView.setPrefHeight(150);
mdModel.selectedItemProperty().bind(listView.getSelectionModel().selectedItemProperty());
//Detail
checkShowMore = new CheckBox();
checkShowMore.setText("Show more details");
VBox detailVBox = new VBox();
Label apiLabel = new Label();
Label labelPlayground = new Label();
detailVBox.getChildren().addAll(
checkShowMore,
new TitledPane("API Binding", apiLabel),
new TitledPane("EasyBind", labelPlayground)
);
// Scene
Scene scene = new Scene(new VBox(listView, detailVBox),400,400);
primaryStage.setScene(scene);
primaryStage.setTitle("JavaFX/EasyBind MVCE");
// --------------------------
// -------- BINDINGS --------
// --------------------------
// API Label Binding
apiLabel.textProperty().bind(Bindings.createStringBinding(
() -> selectedItemBinding.getValue().getDetails().stream()
.map(i -> derivedBinding(i.aProperty(), i.bProperty()))
.map(v->v.getValue())
.collect(Collectors.joining(", "))
, mdModel.selectedItemProperty(), checkShowMore.selectedProperty()));
// EasyBind non-working attempt
/*
ListProperty<ModelItemDetail> obsList = new SimpleListProperty<>(FXCollections.observableArrayList(i->new Observable[] { i.aProperty(), i.bProperty(), checkShowMore.selectedProperty()}));
obsList.bind(selectedItemBinding.flatMap(ModelItem::detailsProperty));
ObservableList<ModelItemDetail> ebDetailList = obsList; // WHY ??
ObservableList<ObservableValue<String>> ebDerivedList = EasyBind.map(ebDetailList, i -> derivedBinding(i.aProperty(), i.bProperty()));
ObservableValue<String> ebDerivedValueBinding = EasyBind.combine(ebDerivedList, stream -> stream.collect(Collectors.joining(", "))).orElse("Nothing to see here, move on");
labelPlayground.textProperty().bind(ebDerivedValueBinding);
*/
// Working EasyBind Binding
labelPlayground.textProperty().bind(
selectedItemBinding
.flatMap(ModelItem::detailsProperty)
.map(l -> derivedBinding(l))
.flatMap(l -> EasyBind.combine(l, stream -> stream.collect(Collectors.joining(", "))))
);
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
}
private ObservableList<ObservableValue<String>> derivedBinding(ObservableList<ModelItemDetail> l) {
return l.stream()
.map(c -> derivedBinding(c.aProperty(), c.bProperty()))
.collect(Collectors.toCollection(FXCollections::observableArrayList));
}
private Binding<String> derivedBinding(ObservableValue<String> someA, ObservableValue<String> someB ) {
return EasyBind.combine(someA, someB, checkShowMore.selectedProperty(),
(a, e, s) -> a + (Boolean.TRUE.equals(s) ? " <" + e + ">" : ""));
}
private ModelItem newModelItem(int number) {
ModelItem item = new ModelItem();
item.itemNumber = number+1;
for (int i=0;i<2;i++) {
ModelItemDetail detail = new ModelItemDetail("A" + (i+item.itemNumber), "B" + (i+item.itemNumber));
item.getDetails().add(detail);
}
return item;
}
/** GUI Model class */
private static class MasterDetailModel {
private ObjectProperty<ModelItem> selectedItemProperty = new SimpleObjectProperty<>();
public ObjectProperty<ModelItem> selectedItemProperty() { return selectedItemProperty; }
public ModelItem getSelectedItem() { return selectedItemProperty.getValue(); }
public void setSelectedItem(ModelItem item) { selectedItemProperty.setValue(item); }
}
/** Domain Model class */
private static class ModelItem {
int itemNumber;
private ListProperty<ModelItemDetail> detailsProperty = new SimpleListProperty<>(FXCollections.observableArrayList());
public ListProperty<ModelItemDetail> detailsProperty() { return detailsProperty; }
public ObservableList<ModelItemDetail> getDetails() { return detailsProperty.getValue(); }
public void setDetails(List<ModelItemDetail> details) { detailsProperty.setValue(FXCollections.observableList(details)); }
public String toString() { return "Item " + itemNumber; }
}
/** Domain Model class */
private static class ModelItemDetail {
public ModelItemDetail(String a, String b) {
setA(a);
setB(b);
}
private StringProperty aProperty = new SimpleStringProperty();
public StringProperty aProperty() { return aProperty; }
public String getA() { return aProperty.get(); }
public void setA(String a) { aProperty.set(a); }
private StringProperty bProperty = new SimpleStringProperty();
public StringProperty bProperty() { return bProperty; }
public String getB() { return bProperty.get(); }
public void setB(String b) { bProperty.set(b); }
}
}