Develop Reference

JavaFX bind choicebox to a property in a collection

With JavaFX, what is the best way to bind ChoiceBox to properties of a collection?
In example below I try to bind ChoiceBox elements to name of an ObservableList beans. This works fine when items are added/removed but not when the property value name change.
I was hoping there is a clean and simple solution to this but haven't yet found any example of it...
The class ExampleBean2 in deliberately not implemented with properties since that object may correspond to a external model class out of my control.
package com.playground;
import org.controlsfx.control.PropertySheet;
import org.controlsfx.property.BeanPropertyUtils;
import javafx.application.Application;
import javafx.beans.Observable;
import javafx.beans.binding.Bindings;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ChoiceBox;
import javafx.scene.control.ListView;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.util.Callback;
public class BindingPlayGround extends Application{
public static void main(String[] args) {
launch();
}
#Override
public void start(Stage primaryStage) throws Exception {
primaryStage.setTitle("FXPlayGround");
Parent content = createContentPane();
Scene scene = new Scene(content, 800, 600);
primaryStage.setScene(scene);
primaryStage.show();
}
protected Parent createContentPane() {
ObservableList<BeanExample2> beans = FXCollections.observableArrayList();
ObservableList<PropertySheet> sheets = FXCollections.observableArrayList();
ListView<PropertySheet> listView = new ListView<PropertySheet>(sheets);
Button addBeanButton = new Button("Add Bean");
addBeanButton.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
BeanExample2 e = new BeanExample2();
e.setName("Name-not-set");
PropertySheet propertySheet = new PropertySheet(BeanPropertyUtils.getProperties(e));
sheets.add(propertySheet);
beans.add(e);
}
});
VBox vBar = new VBox();
vBar.getChildren().add(listView);
vBar.getChildren().add(addBeanButton);
ObservableList<BeanExample2> names = FXCollections.observableArrayList(new Callback<BeanExample2, Observable[]>() {
#Override
public Observable[] call(BeanExample2 param) {
return new Observable[]{new SimpleStringProperty(param, "name")};
}
});
Bindings.bindContent(names, beans);
Button addChoiceBoxButton = new Button("Add ChoiceBox");
addChoiceBoxButton.setOnAction(new EventHandler<ActionEvent>() {
#Override
public void handle(ActionEvent event) {
ChoiceBox<BeanExample2> choiceBox = new ChoiceBox<BeanExample2>(names);
vBar.getChildren().add(choiceBox);
}
});
vBar.getChildren().add(addChoiceBoxButton);
return vBar;
}
static class BeanExample2 {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
#Override
public String toString() {
return "BeanExample2{" +
"name='" + name + '\'' +
'}';
}
}
}

Here
ObservableList<BeanExample2> names = FXCollections.observableArrayList(new Callback<BeanExample2, Observable[]>() {
#Override
public Observable[] call(BeanExample2 param) {
return new Observable[]{new SimpleStringProperty(param, "name")};
}
});
you're creating a new property to listen to for updates that cannot be referenced except from the value returned by the call method. The only relationship between the BeanExample2 instance and the SimpleStringProperty is that the BeanExample2 instance is used as bean for the property, which has no effect besides being available via the getBean() method of the property. The value of the property is never assigned let alone modified on a change of the BeanExample2 instance.
To properly trigger updates in the ObservableList, you need to make sure the element in the array returned by the above method is actually notified of updates. Usually you add the property to the class itself:
public static class BeanExample2 {
public final String getName() {
return this.name.get();
}
private final StringProperty name = new SimpleStringProperty();
public final void setName(String value) {
this.name.set(value);
}
#Override
public String toString() {
return "BeanExample2{"
+ "name='" + name.get() + '\''
+ '}';
}
public final StringProperty nameProperty() {
return this.name;
}
}
And return an array containing the property from the Callback
ObservableList<BeanExample2> names = FXCollections.observableArrayList(new Callback<BeanExample2, Observable[]>() {
#Override
public Observable[] call(BeanExample2 param) {
return new Observable[]{param.nameProperty()};
}
});
Note that currently there seems to be a bug in ChoiceBox that adds entries for every intermediate value to the ChoiceBox.
ComboBox does not have this issue and could be used instead of a ChoiceBox.

GWT RPC array access

I'm writing an application in which data from a text file is saved to the array and late transferred to the widget GWT Highcharts as an array of Number type. I wrote a servlet that writes data from a file into an array, and I'm stuck here. I don't know how to pass the contents of the array to the client part of the application. Is there a quick and easy way to do this?
This code written by me:
DataPointsImpl.java:
package com.pwste.gwt.server;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.pwste.gwt.client.DataPoints;
public class DataPointsImpl extends RemoteServiceServlet implements DataPoints {
private static final long serialVersionUID = 1L;
#Override
public Number[] getDataPoints() throws IOException {
File dataFile = new File("points.txt");
FileReader dataFileReader = new FileReader(dataFile);
BufferedReader dataBufferedReader = new BufferedReader(dataFileReader);
Number[] arrayNumber = new Number[10000];
String dataString = dataBufferedReader.readLine();
for (int i = 0; i < arrayNumber.length; i++) {
arrayNumber[i] = Integer.parseInt(dataString);
dataString = dataBufferedReader.readLine();
}
dataBufferedReader.close();
return arrayNumber;
}
}
DataPoints.java:
package com.pwste.gwt.client;
import java.io.IOException;
import com.google.gwt.user.client.rpc.RemoteService;
import com.google.gwt.user.client.rpc.RemoteServiceRelativePath;
#RemoteServiceRelativePath("dataPoints")
public interface DataPoints extends RemoteService {
Number[] getDataPoints() throws IOException;
}
DataPointsAsync.java:
package com.pwste.gwt.client;
import com.google.gwt.user.client.rpc.AsyncCallback;
public interface DataPointsAsync {
void getDataPoints(AsyncCallback<Number[]> callback);
}

You have to use the Async-Interface on the client side:
private DataPointsAsync dataPointsService = GWT.create(DataPoints.class);
you can use the service in this way:
dataPointsService.getDataPoints(AsyncCallback<Number[]>(){
#Override
public void onSuccess(Number[] result) {
// result contains the returning values
}
#Override
public void onFailure(Throwable caught) {
Window.alert("panic");
}
});

JAX-RS / JAXB : equals()

I'm creating a little webservice with JAX-RS and I cannot access to my GET request http://localhost:8080/MyProject/resources/agenda/{jour}
Here is my code :
package com.project.test;
import javax.xml.bind.annotation.XmlRootElement;
import java.util.List;
import javax.ws.rs.DefaultValue;
import javax.ws.rs.PathParam;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.xml.bind.annotation.*;
#XmlRootElement(name = "activite")
#XmlAccessorType(XmlAccessType.FIELD)
#XmlType(propOrder = {"but","trancheHoraire", "lieu"})
public class Activite
{
//-----------------------------------------------------------------------------
// #XmlElement(name="nomactivite")
private String but;
private TrancheHoraire trancheHoraire;
private String lieu;
//-----------------------------------------------------------------------------
public Activite(){
}
public Activite(String but,TrancheHoraire trancheHoraire, String lieu)
{
this.but = but;
this.trancheHoraire = trancheHoraire;
this.lieu = lieu;
}
//-----------------------------------------------------------------------------
public String getBut() { return but; }
public TrancheHoraire getTrancheHoraire() {
return trancheHoraire;
}
public String getLieu() { return lieu; }
public void setBut(String but) {
this.but = but;
}
public void setTrancheHoraire(TrancheHoraire trancheHoraire) {
this.trancheHoraire = trancheHoraire;
}
public void setLieu(String lieu) {
this.lieu = lieu;
}
public Date getDate (){
return this.getTrancheHoraire().getDate();
}
}
TrancheHoraire class :
package com.project.test;
import javax.xml.bind.annotation.*;
#XmlAccessorType(XmlAccessType.FIELD)
//#XmlType(name = "trancheHoraire", propOrder = {"date", "part_journee"})
public class TrancheHoraire
{
//-----------------------------------------------------------------------------
// #XmlElement(required = true)
private Date date;
// #XmlElement(required = true)
private int part_journee;
public String part_journee_v;
//-----------------------------------------------------------------------------
public TrancheHoraire(){
}
public TrancheHoraire(Date date, int part_journee)
{
this.date = date;
this.part_journee = part_journee;
}
//-----------------------------------------------------------------------------
public Date getDate() { return date; }
public int getpart_journee()
{
return part_journee;
}
}
My Database :
package com.project.test;
import java.util.ArrayList;
import java.util.List;
public class ActiviteBD {
private static List<Activite> activites = new ArrayList<Activite>();
static {
activites.add(new Activite("Réunion", new TrancheHoraire(new Date(01, 10, 2015), 2), "Paris"));
activites.add(new Activite("Vacances", new TrancheHoraire(new Date(02, 10, 2015), 2), "Marseille"));
activites.add(new Activite("Resto", new TrancheHoraire(new Date(03, 10, 2015), 2), "Lyon"));
}
public static List<Activite> getActivites() {
return activites;
}
}
And I call webservices with this class :
package com.project.test;
import java.util.List;
import javax.ws.rs.DefaultValue;
import javax.ws.rs.GET;
import javax.ws.rs.HeaderParam;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
/**
*
* #author rcaboni
*/
#Path("/agenda")
public class Resource
{
#GET
#Produces("application/xml")
public List<Activite> getActivites() {
return ActiviteBD.getActivites();
}
#GET
#Path("{jour}")
#Produces("application/xml")
public Activite getActiviteByDate(#PathParam("jour") int jour){
System.out.println("getActivite");
Activite tranche = new Activite("Réunion", new TrancheHoraire(new Date(jour, 10, 2015), 2), "Marseille");
TrancheHoraire th = tranche.getTrancheHoraire();
System.out.println(tranche.getDate());
for (Activite _current : ActiviteBD.getActivites()) {
System.out.println(_current.getTrancheHoraire());
if (th.equals(_current.getTrancheHoraire())) {
System.out.println(_current.getTrancheHoraire());
return _current;
}
}
return null;
}
}
If I call /agenda, it returns all my activities.
Like this :
However, if I call /agenda/1 , it should return my first activitie...
In my console : getTrancheHoraire returns something like this : com.project.test.TrancheHoraire#75a630fb
I've read plugin on Equals() class is the only one solution.
Could you help me ? :)

"I've read plugin on Equals() class is the only one solution."
I guess "plugin on" means override. If not, then that's you it should mean. You need to override it, and describe how the objects will be determined equal. (It should also be noted, when override equals, you should also override hashcode).
See when should I override Equals function?
That being said, most IDEs, will be able to generate this for you. For example, with Netbeans, I just right click the class, select "Insert Code" and select equals() and hashcode(). Then select the properties I want to include in the comparison. I selected all, and got this
#Override
public int hashCode() {
int hash = 5;
hash = 79 * hash + Objects.hashCode(this.date);
hash = 79 * hash + this.part_journee;
hash = 79 * hash + Objects.hashCode(this.part_journee_v);
return hash;
}
#Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final TrancheHoraire other = (TrancheHoraire) obj;
if (!Objects.equals(this.date, other.date)) {
return false;
}
if (this.part_journee != other.part_journee) {
return false;
}
if (!Objects.equals(this.part_journee_v, other.part_journee_v)) {
return false;
}
return true;
}
I know Eclipse has similar feature.
As an aside, your comparison looks kind of odd. Why do you need to create a new Activite? The method is getActiviteByDate, so why don't you just look for Activites with the date.

Try adding a / before your {jour} declaration in the #Path annotation, like so:
#Path("/{jour}")
The mapping you've got currently looks like it may be routing requests to /agenda1.

issue with this tutorial:Populate a tableview using database in JavaFX

I get a nullpointerxception when following this tutorial:
Populate a tableview using database in JavaFX .
I modified it to make it simpler and fit my needs:
Instead of Usermaster, I have Person object.
while(rs.next()){
Person per = new Person();
per.ClientID.set(rs.getInt(1));
per.FirstName.set(rs.getString(2));
per.LastName.set(rs.getString(3));
The code stops at per.ClientID.set(rs.getInt(1)); due to nullpointerxception.
If I make system.out.println(rs.getInt(1)) (or any other column), I get the value... But it appears that I can't pass it to my object per.
All Person object vars are SimpleString/IntergerProperty type, as shown in the tutorial.
Can someone help me to identify the mistake I made in coding this?
Thank you
**Answer: need to initialize values.
Now I have no errors, but my table is not populating...
Full code:
a) Main App
package tableview;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class MainApp extends Application {
public static void main(String[] args) {
// TODO Auto-generated method stub
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("view/FXMLTable.fxml"));
Scene scene = new Scene(root);
primaryStage.setScene(scene);
primaryStage.show();
}
}
Model Class:
package tableview.model;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
public class Person {
public SimpleIntegerProperty ClientID = new SimpleIntegerProperty();
public SimpleStringProperty FirstName = new SimpleStringProperty();
public SimpleStringProperty LastName = new SimpleStringProperty();
public SimpleIntegerProperty getClientID() {
return ClientID;
}
public SimpleStringProperty getFirstname() {
return FirstName;
}
public SimpleStringProperty getLastName() {
return LastName;
}
public IntegerProperty clientIDProperty(){
return ClientID;
}
public StringProperty firstNameProperty(){
return FirstName;
}
public StringProperty lastNameProperty(){
return LastName;
}
}
Controller Class:
package tableview.view;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import tableview.model.Person;
public class FXMLTableController{
#FXML
public TableView<Person> tableview ;
#FXML
private TableColumn<Person, Number> clientIdColumn;
#FXML
private TableColumn<Person, String> firstNameColumn;
#FXML
private TableColumn<Person, String> lastNameColumn;
#FXML
private void initialize() {
assert tableview != null : "fx:id=\"tableview\" was not injected: check your FXML file 'UserMaster.fxml'.";
clientIdColumn.setCellValueFactory(cellData -> cellData.getValue().
clientIDProperty());
firstNameColumn.setCellValueFactory(cellData -> cellData.getValue()
.firstNameProperty());
lastNameColumn.setCellValueFactory(cellData -> cellData.getValue()
.lastNameProperty());
buildData();
}
private ObservableList<Person> data;
public void buildData(){
data = FXCollections.observableArrayList();
Connection con = null;
try {
Class.forName("org.sqlite.JDBC");
con = DriverManager.getConnection("jdbc:sqlite:tableviewdb.db");
String SQL = "Select * from INFO";
ResultSet rs = con.createStatement().executeQuery(SQL);
while(rs.next()){
Person per = new Person();
per.ClientID.set(rs.getInt("CLIENTID"));
per.FirstName.set(rs.getString("FIRSTNAME"));
per.LastName.set(rs.getString("LASTNAME"));
data.add(per);
}
tableview = new TableView<Person>();
tableview.setItems(data);
System.out.println(tableview.getItems().get(1).ClientID);
}
catch(Exception e){
e.printStackTrace();
System.out.println("Error on Building Data");
}
}
}

ClientID is null. You didn't initialize it.
If it's a property, you should create the proper getter and setters for it and not use the property directly. Besides you should never use 1, 2, etc in the ResultSet's getter. It's better practice to use the column names.

Cannot create Java List

I want to use this code and create JSF 2.0 table.
This is the Java Code of the Managed bean:
import java.io.Serializable;
import javax.enterprise.context.SessionScoped;
// or import javax.faces.bean.SessionScoped;
import javax.inject.Named;
/* include SQL Packages */
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import javax.annotation.PostConstruct;
import javax.sql.DataSource;
import javax.annotation.Resource;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
// or import javax.faces.bean.ManagedBean;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import javax.faces.model.DataModel;
import javax.faces.model.ListDataModel;
import org.glassfish.osgicdi.OSGiService;
#Named("ApplicationController")
#SessionScoped
public class Application implements Serializable {
private List<Item> list;
private transient DataModel<Item> model;
private Item item = new Item();
private boolean edit;
#PostConstruct
public void init() {
// list = dao.list();
// Actually, you should retrieve the list from DAO. This is just for demo.
list = new ArrayList<Item>();
list.add(new Item(1L, "item1"));
list.add(new Item(2L, "item2"));
list.add(new Item(3L, "item3"));
}
public void add() {
// dao.create(item);
// Actually, the DAO should already have set the ID from DB. This is just for demo.
item.setId(list.isEmpty() ? 1 : list.get(list.size() - 1).getId() + 1);
list.add(item);
item = new Item(); // Reset placeholder.
}
public void edit() {
item = model.getRowData();
edit = true;
}
public void save() {
// dao.update(item);
item = new Item(); // Reset placeholder.
edit = false;
}
public void delete() {
// dao.delete(item);
list.remove(model.getRowData());
}
public List<Item> getList() {
return list;
}
public DataModel<Item> getModel() {
if (model == null) {
model = new ListDataModel<Item>(list);
}
return model;
}
public Item getItem() {
return item;
}
public boolean isEdit() {
return edit;
}
}
I get this problem when I import the code into Netbeans:
How I can declare the Java list in order to work?
Best wishes
EDIT I edited the code this way:
import java.io.Serializable;
import javax.enterprise.context.SessionScoped;
// or import javax.faces.bean.SessionScoped;
import javax.inject.Named;
/* include SQL Packages */
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import javax.annotation.PostConstruct;
import javax.sql.DataSource;
import javax.annotation.Resource;
import javax.faces.context.FacesContext;
import javax.inject.Inject;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
// or import javax.faces.bean.ManagedBean;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import javax.faces.model.DataModel;
import javax.faces.model.ListDataModel;
import org.glassfish.osgicdi.OSGiService;
#Named("ApplicationController")
#SessionScoped
public class Application implements Serializable {
public Application() {
}
private List<Application> list;
private transient DataModel<Application> model;
private Application item = new Application();
private boolean edit;
private Application(long l, String string) {
throw new UnsupportedOperationException("Not yet implemented");
}
#PostConstruct
public void init() {
// list = dao.list();
// Actually, you should retrieve the list from DAO. This is just for demo.
list = new ArrayList<Application>();
list.add(new Application(1L, "item1"));
list.add(new Application(2L, "item2"));
list.add(new Application(3L, "item3"));
}
public void add() {
// dao.create(item);
// Actually, the DAO should already have set the ID from DB. This is just for demo.
item.setId(list.isEmpty() ? 1 : list.get(list.size() - 1).getId() + 1);
list.add(item);
item = new Application(); // Reset placeholder.
}
public void edit() {
item = model.getRowData();
edit = true;
}
public void save() {
// dao.update(item);
item = new Application(); // Reset placeholder.
edit = false;
}
public void delete() {
// dao.delete(item);
list.remove(model.getRowData());
}
public List<Application> getList() {
return list;
}
public DataModel<Application> getModel() {
if (model == null) {
model = new ListDataModel<Application>(list);
}
return model;
}
public Application getItem() {
return item;
}
public boolean isEdit() {
return edit;
}
private void setId(int i) {
throw new UnsupportedOperationException("Not yet implemented");
}
private int getId() {
throw new UnsupportedOperationException("Not yet implemented");
}
}
Do you see any mistakes?

You have to define the Item class.
UPDATE:
To keep the code in the first form. You should have a Item class.
public class Item {
private long id;
private String name;
public Item() {}
public Item(long id, String name) {
this.id = id;
this.name = name;
}
//getters and setters for the attributes...
}
Now, in your updated code, you're using a list of Application objects. So your Application class should have 2 attributes of long and String type:
//annotations here...
public class Application implements Serializable {
private long id;
private String name;
//getters and setters for these attributes...
public Application() {
//keep your actual code here
}
//we have to add a constructor that receives a long and a String
//to initialize the attributes values.
public Application(long id, String name) {
this.id = id;
this.name = name;
}
//your actual code...
}
Second option is not a good practice, I recommend you separate the Backing Bean (Managed Bean) class from your model classes (in this case, the Item class).

Do not focus on article's code examples only. Read the article's text as well. The text is not written for decoration only :)
The Item class is just a simple model object, its code should be straightforward enough. A Serializable Javabean with two properties Long id and String value, a default constructor and a constructor filling both properties, a bunch of appropriate getters/setters, equals() and hashCode() overriden.
You can almost autogenerate it in its entirety with a bit decent IDE like Eclipse.

From this version of the API, the Item constructor requires a String parameter, which you are not providing. I think your IDE has pulled in that class by accident.
Reading the example from the link in the question I believe you need to supply your own Item class (and import it correctly) which will need a no-argument constructor and one that takes a long and a String.