I need help creating a null-safe BooleanBinding. It has to be null-safe since I can not provide default values for all attributes in the model (one reason: the model contains enumerations). My first approach has been as follows:
executeButtonDisabled.bind(missionProperty().isNotNull().and(missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.CREATED)));
final BooleanBinding isNotExecutingBinding = missionProperty().isNotNull().and(missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.EXECUTING));
completeButtonDisabled.bind(isNotExecutingBinding);
cancelButtonDisabled.bind(isNotExecutingBinding)
But that approach does not work because the complete expression is evaluated which results in a NullPointerException (but it correctly updates the buttons, when a property is provided). Now I am trying to use the Bindings class as suggested in JavaFX binding and null values, but I can't make it work. Here's my current approach:
final BooleanBinding isNotCreatedBinding = Bindings.createBooleanBinding(
() -> mission.isNull().getValue()
? true
: missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.CREATED).getValue());
final BooleanBinding isNotExecutingBinding = Bindings.createBooleanBinding(
() -> mission.isNull().getValue()
? true
: missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.EXECUTING).getValue());
executeButtonDisabled.bind(isNotCreatedBinding);
completeButtonDisabled.bind(isNotExecutingBinding);
cancelButtonDisabled.bind(isNotExecutingBinding);
But this does not work and I do not understand why. It seems that the property binding for modelProperty() does not work here! Can you explain to me how-to convert the first working solution (at least without null) to a proper null-safe solution?
Edit 2016-04-26: The suggested solution does not work, therefore I created a simple fully-working example:
Mission.java:
package de.florianwolters.example.javafx.bindings;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
public class Mission {
enum Status {
CREATED,
EXECUTING,
COMPLETED,
CANCELED;
}
private final StringProperty shortName = new SimpleStringProperty();
private final ObjectProperty<Status> status = new SimpleObjectProperty<>();
public Mission(final String shortName) {
this.setShortName(shortName);
this.setStatus(Status.CREATED);
}
public String getShortName() {
return shortNameProperty().get();
}
public void setShortName(final String shortName) {
shortNameProperty().set(shortName);
}
public StringProperty shortNameProperty() {
return shortName;
}
public Status getStatus() {
return statusProperty().get();
}
public void setStatus(final Status status) {
statusProperty().set(status);
}
public ObjectProperty<Status> statusProperty() {
return status;
}
}
MissionDetailsViewModel.java:
package de.florianwolters.example.javafx.bindings;
import javafx.beans.binding.Bindings;
import javafx.beans.binding.BooleanBinding;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.ReadOnlyBooleanProperty;
import javafx.beans.property.ReadOnlyBooleanWrapper;
import javafx.beans.property.SimpleObjectProperty;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public final class MissionDetailsViewModel {
/**
* The logger used for logging in the `MissionDetailsViewModel` class.
*/
private static final Logger LOGGER = LoggerFactory.getLogger(
MissionDetailsViewModel.class);
private ObjectProperty<Mission> mission = new SimpleObjectProperty<>();
private final ReadOnlyBooleanWrapper executeButtonDisabled = new ReadOnlyBooleanWrapper(true);
private final ReadOnlyBooleanWrapper completeButtonDisabled = new ReadOnlyBooleanWrapper(true);
private final ReadOnlyBooleanWrapper cancelButtonDisabled = new ReadOnlyBooleanWrapper(true);
/**
* Constructs a `MissionDetailsViewModel`.
*/
public MissionDetailsViewModel(final ObjectProperty<Mission> mission) {
this.mission.bind(mission);
// partialWorkingBinding();
notWorkingBinding();
}
private void notWorkingBinding() {
final BooleanBinding isNotCreatedBinding = Bindings.createBooleanBinding(
() -> missionProperty().isNull().get()
? true
: missionProperty().get().statusProperty().isNotEqualTo(Mission.Status.CREATED).get(),
missionProperty());
final BooleanBinding isNotExecutingBinding = Bindings.createBooleanBinding(
() -> mission.isNull().get()
? true
: missionProperty().get().statusProperty().isNotEqualTo(Mission.Status.EXECUTING).get(),
missionProperty());
executeButtonDisabled.bind(isNotCreatedBinding);
completeButtonDisabled.bind(isNotExecutingBinding);
cancelButtonDisabled.bind(isNotExecutingBinding);
}
private void partialWorkingBinding() {
executeButtonDisabled.bind(missionProperty().isNotNull().and(missionProperty().get().statusProperty().isNotEqualTo(Mission.Status.CREATED)));
final BooleanBinding isNotExecutingBinding = missionProperty().isNotNull().and(missionProperty().get().statusProperty().isNotEqualTo(Mission.Status.EXECUTING));
completeButtonDisabled.bind(isNotExecutingBinding);
cancelButtonDisabled.bind(isNotExecutingBinding);
}
public boolean isExecuteButtonDisabled() {
return executeButtonDisabledProperty().get();
}
public ReadOnlyBooleanProperty executeButtonDisabledProperty() {
return executeButtonDisabled;
}
public boolean isCompleteButtonDisabled() {
return completeButtonDisabledProperty().get();
}
public ReadOnlyBooleanProperty completeButtonDisabledProperty() {
return completeButtonDisabled;
}
public boolean isCancelButtonDisabled() {
return cancelButtonDisabledProperty().get();
}
public ReadOnlyBooleanProperty cancelButtonDisabledProperty() {
return cancelButtonDisabled;
}
public Mission getMission() {
return missionProperty().get();
}
public void setMission(final Mission mission) {
missionProperty().set(mission);
}
public ObjectProperty<Mission> missionProperty() {
return mission;
}
}
MissionDetailsViewModelTest.java:
package de.florianwolters.example.javafx.bindings;
import static eu.lestard.assertj.javafx.api.Assertions.assertThat;
import javafx.beans.property.SimpleObjectProperty;
import org.junit.Before;
import org.junit.Test;
public final class MissionDetailsViewModelTest {
private Mission mission;
private MissionDetailsViewModel viewModel;
#Before
public void setUp() {
mission = new Mission("My Short Name");
viewModel = new MissionDetailsViewModel(new SimpleObjectProperty<Mission>(mission));
}
#Test
public void testInitialValues() {
assertThat(viewModel.executeButtonDisabledProperty()).isFalse();
assertThat(viewModel.completeButtonDisabledProperty()).isTrue();
assertThat(viewModel.cancelButtonDisabledProperty()).isTrue();
}
#Test
public void testMissionStatusSetToExecuting() {
mission.setStatus(Mission.Status.EXECUTING);
assertThat(viewModel.executeButtonDisabledProperty()).isTrue();
assertThat(viewModel.completeButtonDisabledProperty()).isFalse();
assertThat(viewModel.cancelButtonDisabledProperty()).isFalse();
}
#Test
public void testMissionStatusSetToCompleted() {
mission.setStatus(Mission.Status.COMPLETED);
assertThat(viewModel.executeButtonDisabledProperty()).isTrue();
assertThat(viewModel.completeButtonDisabledProperty()).isTrue();
assertThat(viewModel.cancelButtonDisabledProperty()).isTrue();
}
#Test
public void testMissionStatusSetToCanceled() {
mission.setStatus(Mission.Status.CANCELED);
assertThat(viewModel.executeButtonDisabledProperty()).isTrue();
assertThat(viewModel.completeButtonDisabledProperty()).isTrue();
assertThat(viewModel.cancelButtonDisabledProperty()).isTrue();
}
}
The unit test fails with the code above (the method notWorkingBinding() is used) but works with the method partialWorkingBinding(). What am I doing wrong?
You set up the calculation function for isNotCreatedBinding, but you didn't set the dependencies for the binding. You need to add mision as dependency:
Bindings.createBooleanBinding(
() -> mission.isNull().getValue()
? true
: missionProperty().get().statusProperty().isNotEqualTo(MissionStatus.CREATED).getValue(), mission);
EDIT
You need to listen to the statusProperty instead of missionProperty, which will not work with createBooleanBinding when missionProperty().get() == null.
But you can use a When binding:
(is causing a NullPointerException as already mentioned in the question)
BooleanBinding isNotCreatedBinding = new When(mission.isNotNull()).then(mission.get().statusProperty().isNotEqualTo(Mission.Status.CREATED)).otherwise(false);
Or a more low-level solution:
missionProperty().addListener((ov, m, m1) -> {
if (m1 != null) {
executeButtonDisabled.bind(m1.statusProperty().isNotEqualTo(Mission.Status.CREATED));
}else {
executeButtonDisabled.unbind();
executeButtonDisabled.set(false);
}
});
Tomas Mikula's ReactFX framework (v 2.0) has this functionality built in:
import org.reactfx.value.Val;
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.property.SimpleObjectProperty;
public class NestedBindingTest {
public static void main(String[] args) {
BooleanProperty disable = new SimpleBooleanProperty();
disable.addListener((obs, wasDisabled, isNowDisabled) ->
System.out.println("disable: "+wasDisabled+" -> "+isNowDisabled));
ObjectProperty<Item> item = new SimpleObjectProperty<>();
Val<Item.Status> status = Val.flatMap(item, Item::statusProperty);
disable.bind(status.map(s -> s == Item.Status.PENDING).orElseConst(true));
Item i = new Item();
System.out.println("Setting item");
item.set(i);
System.out.println("Setting item status to PENDING");
i.setStatus(Item.Status.PENDING);
System.out.println("Setting item status to READY");
i.setStatus(Item.Status.READY);
System.out.println("Setting item to null");
item.set(null);
}
public static class Item {
public enum Status {PENDING, READY}
private final ObjectProperty<Status> status = new SimpleObjectProperty<>();
public final ObjectProperty<Status> statusProperty() {
return this.status;
}
public final NestedBindingTest.Item.Status getStatus() {
return this.statusProperty().get();
}
public final void setStatus(final NestedBindingTest.Item.Status status) {
this.statusProperty().set(status);
}
}
}
Related
When working with azure BlobStorage I'm quite new to this topic but I managed to get it working in java. So we have some xml files saved there and collect the file list as strings. Now I've tried to create a unit tests to verify it stays working and since the getFiles() function is a very small I expected it to be very simple to test.
#Override
public List<String> getFiles(ExecutionContext context) {
return StreamSupport.stream(blobContainerClient.listBlobs().spliterator(), true)
.map(BlobItem::getName)
.collect(Collectors.toList());
}
I can mock the com.azure.storage.blob.blobContainerClient and its function listBlobs, but when trying to create the PagedIterable from a simple List I cannot make it fit the right data types or it runs into an endless loop.
Since the functionality is so minimal, we would just skip to test this, but ou of curiosity I just want to know if it could be tested or what is wrong with my code:
import com.azure.core.http.rest.*;
import com.azure.core.util.IterableStream;
import com.azure.storage.blob.BlobContainerClient;
import com.azure.storage.blob.models.BlobItem;
import com.microsoft.azure.functions.ExecutionContext;
import lombok.SneakyThrows;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import reactor.core.CoreSubscriber;
import reactor.core.Fuseable;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import java.util.function.Supplier;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.Mockito.*;
class BlobstoreConnectorListFilesTest {
private final BlobContainerClient blobContainerClientMock = mock(BlobContainerClient.class);
private final ExecutionContext context = mock(ExecutionContext.class);
private final String id1 = UUID.randomUUID().toString();
private final String id2 = UUID.randomUUID().toString();
#BeforeEach
void setUp() {
BlobItem item1 = mock(BlobItem.class);
when(item1.getName()).thenReturn(id1 + ".xml");
BlobItem item2 = mock(BlobItem.class);
when(item2.getName()).thenReturn(id2 + ".xml");
List<BlobItem> arrayList = new ArrayList<>();
arrayList.add(item1);
arrayList.add(item2);
Mono<PagedResponse<BlobItem>> monoSource = new Mono<>() {
private final Page<BlobItem> page = new Page<>() {
#Override
public IterableStream<BlobItem> getElements() {
return new IterableStream<>(Flux.fromIterable(arrayList));
}
#Override
public String getContinuationToken() {
return null;
}
};
final PagedResponseBase<String, BlobItem> pagedResponseBase = new PagedResponseBase<>(null, 200, null, page
, null);
final Fuseable.QueueSubscription<BlobItem> fuseableQueueSubscription = new Fuseable.QueueSubscription<>() {
#Override
public void request(long l) {
}
#SneakyThrows
#Override
public void cancel() {
throw new InterruptedException();
}
#Override
public int size() {
return arrayList.size();
}
#Override
public boolean isEmpty() {
return arrayList.isEmpty();
}
#Override
public void clear() {
arrayList.clear();
}
#Override
public BlobItem poll() {
var value = arrayList.stream().findFirst().orElse(null);
if(value!=null){
arrayList.remove(value);
}
return value;
}
#Override
public int requestFusion(int i) {
return 0;
}
};
#Override
public void subscribe(CoreSubscriber<? super PagedResponse<BlobItem>> coreSubscriber) {
coreSubscriber.onNext(pagedResponseBase);
coreSubscriber.onSubscribe(fuseableQueueSubscription);
}
};
Supplier<Mono<PagedResponse<BlobItem>>> blobItemSupplier = () -> monoSource;
PagedFlux<BlobItem> pagedFlux = new PagedFlux<>(blobItemSupplier);
PagedIterable<BlobItem> leaflets = new PagedIterable<>(pagedFlux);
doReturn(leaflets).when(blobContainerClientMock).listBlobs();
}
#Test
void getAllFiles() {
BlobstoreConnector connector = new BlobstoreConnector(blobContainerClientMock);
List<String> actual = connector.getFiles(context);
assertEquals(2, actual.size());
assertTrue(actual.stream().anyMatch(fileName -> fileName.equals(id1 + ".xml")));
assertTrue(actual.stream().anyMatch(fileName -> fileName.equals(id2 + ".xml")));
}
}
I am trying to work with PersistentActor in Akka.
I tried the basic example provided in the Akka documentation at https://doc.akka.io/docs/akka/current/persistence.html.
I am getting the following error at the starting of the actor:
Caused by: java.lang.IllegalArgumentException: Default journal plugin
is not configured, see 'reference.conf' at
akka.persistence.Persistence$.verifyPluginConfigIsDefined(Persistence.scala:193)
at
akka.persistence.Persistence.defaultJournalPluginId$lzycompute(Persistence.scala:228)
at
akka.persistence.Persistence.defaultJournalPluginId(Persistence.scala:226)
at
akka.persistence.Persistence.journalConfigFor(Persistence.scala:336)
at akka.persistence.Eventsourced.$init$(Eventsourced.scala:97) at
akka.persistence.AbstractPersistentActor.(PersistentActor.scala:455)
at
org.spituk.learning.akka.samples.ExamplePersistentActor.(ExamplePersistentActor.java:72)
The code I tried is like:
import akka.actor.ActorRef;
import akka.actor.ActorSystem;
import akka.actor.Props;
import akka.persistence.AbstractPersistentActor;
import akka.persistence.SnapshotOffer;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
class Cmd implements Serializable {
private static final long serialVersionUID = 1L;
private final String data;
public Cmd(String data) {
this.data = data;
}
public String getData() {
return data;
}
}
class Evt implements Serializable {
private static final long serialVersionUID = 1L;
private final String data;
public Evt(String data) {
this.data = data;
}
public String getData() {
return data;
}
}
class ExampleState implements Serializable {
private static final long serialVersionUID = 1L;
private final ArrayList<String> events;
public ExampleState() {
this(new ArrayList<>());
}
public ExampleState(ArrayList<String> events) {
this.events = events;
}
public ExampleState copy() {
return new ExampleState(new ArrayList<>(events));
}
public void update(Evt evt) {
events.add(evt.getData());
}
public int size() {
return events.size();
}
#Override
public String toString() {
return events.toString();
}
}
public class ExamplePersistentActor extends AbstractPersistentActor {
private int snapShotInterval = 1000;
private ExampleState state = new ExampleState();
public static Props props() {
return Props.create(ExamplePersistentActor.class);
}
public int getNumEvents() {
return state.size();
}
#Override
public String persistenceId() {
return "sample-id-1";
}
#Override
public Receive createReceiveRecover() {
return receiveBuilder()
.match(Evt.class, state::update)
.match(SnapshotOffer.class, ss -> state = (ExampleState) ss.snapshot())
.build();
}
#Override
public Receive createReceive() {
return receiveBuilder()
.match(
Cmd.class,
c -> {
final String data = c.getData();
final Evt evt = new Evt(data + "-" + getNumEvents());
System.out.println("Cmd received::" + c);
persist(
evt,
(Evt e) -> {
state.update(e);
getContext().getSystem().getEventStream().publish(e);
if (lastSequenceNr() % snapShotInterval == 0 && lastSequenceNr() != 0)
// IMPORTANT: create a copy of snapshot because ExampleState is mutable
saveSnapshot(state.copy());
});
})
.matchEquals("print", s -> System.out.println(state))
.build();
}
public static void main(String[] args) throws IOException {
ActorSystem persistentSystem = ActorSystem.create("persistent-system");
ActorRef persistentSystemActor = persistentSystem.actorOf(ExamplePersistentActor.props());
persistentSystemActor.tell(new Cmd("Hello"), ActorRef.noSender());
System.in.read();
persistentSystem.terminate();
}
}
I have not defined any configurations for the persistence intend to use the built-in default plugins. Can someone please help me with this?
I had to add the following to the application.conf file:
akka.persistence.journal.plugin = "akka.persistence.journal.leveldb"
akka.persistence.snapshot-store.plugin = "akka.persistence.snapshot-store.local"
akka.persistence.journal.leveldb.dir = "target/example/journal"
akka.persistence.snapshot-store.local.dir = "target/example/snapshots"
# DO NOT USE THIS IN PRODUCTION !!!
akka.persistence.journal.leveldb.native = false
I can use an extractor (Callback<E, Observable[]> extractor) to make a ListProperty fire change events if one of its elements changed one of its properties (update event).
Update Change Event in ObservableList
Is there an equivalent for ObjectProperty<>? I have an SimpleObjectProperty which I want to fire events when properties of it's value (another bean type) change (update change events).
Sample code:
public class TestBean {
public static <T extends TestBean> Callback<T, Observable[]> extractor() {
return (final T o) -> new Observable[] { o.testPropertyProperty() };
}
private final StringProperty testProperty = new SimpleStringProperty();
public final StringProperty testPropertyProperty() {
return this.testProperty;
}
public final String getTestProperty() {
return this.testPropertyProperty().get();
}
public final void setTestProperty(final String testProperty) {
this.testPropertyProperty().set(testProperty);
}
}
public class SomeType {
/**
* How can I listen for changes of TestBean#testProperty?
*/
private final ObjectProperty<TestBean> property = new SimpleObjectProperty<>();
}
I want to receive change events if the value of SomeType#property changes, but also, if SomeType#property#testProperty changes.
I cannot just listen for SomeType#property#testProperty, since I would not be notified when SomeType#property was changed (I would then listen on the wrong object for changes).
I want to receive change events if value of SomeType#property changes, but also, if SomeType#property#testProperty changes.
I cannot just listen for SomeType#property#testProperty, since I would not be notified, when SomeType#property was changed (I would then listen on the wrong object for changes).
This is a limitation of sorts of the current iteration of JavaFX. The built-in way is unreliable and you're better off using 3rd party libraries. See this answer for more information.
For you case, ReactFX can be utilized in a similar way:
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import org.reactfx.value.Val;
import org.reactfx.value.Var;
class TestBean {
private final StringProperty testProperty = new SimpleStringProperty();
public final StringProperty testPropertyProperty() { return testProperty; }
public final String getTestProperty() { return testProperty.get(); }
public final void setTestProperty(String newTestProperty) { testProperty.set(newTestProperty); }
}
public class SomeType {
private final ObjectProperty<TestBean> property = new SimpleObjectProperty<>();
public final ObjectProperty<TestBean> propertyProperty() { return property; }
public final TestBean getProperty() { return property.get(); }
public final void setProperty(TestBean newProperty) { property.set(newProperty); }
public static void main(String[] args) {
SomeType someType = new SomeType();
Var<String> chainedTestProperty = Val.selectVar(someType.propertyProperty(), TestBean::testPropertyProperty);
chainedTestProperty.addListener((obs, oldVal, newVal) -> System.out.println(obs + " " + oldVal + "->" + newVal));
//Tests
someType.setProperty(new TestBean());
someType.getProperty().setTestProperty("s1");
TestBean bean2 = new TestBean();
bean2.setTestProperty("s2");
someType.setProperty(bean2);
someType.setProperty(new TestBean());
}
}
Output:
org.reactfx.value.FlatMappedVar#7aec35a null->s1
org.reactfx.value.FlatMappedVar#7aec35a s1->s2
org.reactfx.value.FlatMappedVar#7aec35a s2->null
The key line
Var<String> chainedTestProperty = Val.selectVar(someType.propertyProperty(), TestBean::testPropertyProperty);
is a sort of listener chaining. The first argument is a property (OvservableValue) of some type Type. The second argument is the "sub"-property of some other type Type2 inside Type, which is given as a function from Type to that property.
Now whenever any "links" in the chain change, you are notified. You can continue to listen to changes in sub-sub-... properties by continuously chaining ovservables this way.
I came up with the following:
public class ObservableValueProperty<T> extends SimpleObjectProperty<T> {
private InvalidationListener listener = null;
private final Callback<T, Observable[]> extractor;
public ObservableValueProperty() {
this(null);
}
public ObservableValueProperty(final Callback<T, Observable[]> extractor) {
this.extractor = extractor;
}
#Override
protected void fireValueChangedEvent() {
super.fireValueChangedEvent();
}
#Override
public void setValue(final T v) {
if (extractor != null) {
final T oldValue = super.get();
if (oldValue != null) {
for (final Observable o : extractor.call(oldValue)) {
o.removeListener(listener);
}
}
listener = o -> fireValueChangedEvent();
for (final Observable o : extractor.call(v)) {
o.addListener(listener);
}
}
super.setValue(v);
}
}
public class ObservableValuePropertyTest4 implements ChangeListener<Object> {
#BeforeClass
public static void setUpBeforeClass() throws Exception {
}
#AfterClass
public static void tearDownAfterClass() throws Exception {
}
#Before
public void setUp() throws Exception {
}
#After
public void tearDown() throws Exception {
}
static class NestedBean {
StringProperty nestedProperty = new SimpleStringProperty("hans");
public static <T extends NestedBean> Callback<T, Observable[]> extractor() {
return (final T o) -> new Observable[] { o.nestedProperty };
}
#Override
public boolean equals(final Object obj) {
if (obj instanceof NestedBean) {
System.err.println(this.nestedProperty.get() + " " + ((NestedBean) obj).nestedProperty.get());
return Objects.equal(this.nestedProperty.get(), ((NestedBean) obj).nestedProperty.get());
}
return false;
}
}
private ObservableValueProperty<NestedBean> p;
private NestedBean nestedBean;
private String newNestedValue = null;
#Test
public void test01() {
p = new ObservableValueProperty<>(NestedBean.extractor());
nestedBean = new NestedBean();
p.setValue(nestedBean);
p.addListener(this);
nestedBean.nestedProperty.set("peter");
assertEquals("peter", newNestedValue);
}
#Override
public void changed(final ObservableValue<? extends Object> observable, final Object oldValue,
final Object newValue) {
System.err.println("Changed");
newNestedValue = nestedBean.nestedProperty.get();
}
}
Unfortunately, this does not fire any change events because of ExpressionHelper$SingleChange:
#Override
protected void fireValueChangedEvent() {
final T oldValue = currentValue;
currentValue = observable.getValue();
final boolean changed = (currentValue == null)? (oldValue != null) : !currentValue.equals(oldValue);
if (changed) {
try {
listener.changed(observable, oldValue, currentValue);
} catch (Exception e) {
Thread.currentThread().getUncaughtExceptionHandler().uncaughtException(Thread.currentThread(), e);
}
}
}
This checks for equality and only if not equal, notifies all listeners. When I trigger fireValueChangedEvent() the value has already changed, and new- and old values are equal, therefore no notification to listeners.
I had the same problem last week, and after many tries, I found a solution that seems to work as expected:
I created a new class called ObjectXProperty<E>, that has the same interface of an ObjectProperty<E>;
It has constructors that can accept a Callback<E,Observable[]>, our extractor function;
Inside the ObjectXProperty, I use a SimpleObjectProperty that deleguates all methods;
The magic trick lies in the set(E value) methods : I create an ObjectBinding that simply send back the value, but it uses the extractor function to decide when it's become invalidated!
This trick will not be applied if the bind method was used previously on the ObjectXProperty, to let the "real" binding do his job; it will work again if the unbind method is called;
Here's my new class ObjectXProperty<E> :
import javafx.beans.InvalidationListener;
import javafx.beans.Observable;
import javafx.beans.binding.Bindings;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.util.Callback;
/**
*
* #author Claude Bouchard - 2017
*/
public class ObjectXProperty<E> extends ObjectProperty<E> {
SimpleObjectProperty<E> p;
Callback<E, Observable[]> extractor;
boolean externalBound = false;
public ObjectXProperty(Callback<E, Observable[]> extractor) {
this.extractor = extractor;
}
public ObjectXProperty(E init, Callback<E, Observable[]> extractor) {
p = new SimpleObjectProperty();
this.extractor = extractor;
set(init);
}
public ObjectXProperty(Object bean, String name, Callback<E, Observable[]> extractor) {
p = new SimpleObjectProperty(bean, name);
this.extractor = extractor;
}
public ObjectXProperty(Object bean, String name, E init, Callback<E, Observable[]> extractor) {
p = new SimpleObjectProperty(bean, name);
this.extractor = extractor;
set(init);
}
#Override
public void set(E value) {
if (!externalBound) {
if (value != null) {
p.bind(Bindings.createObjectBinding(() -> {
return value;
}, extractor.call(value)));
} else {
p.bind(Bindings.createObjectBinding(() -> {
return value;
}, new Observable[]{}));
}
} else {
p.set(value); //As expected, it will throw a java.lang.RuntimeException
}
}
#Override
public E get() {
return p.get();
}
#Override
public void addListener(ChangeListener<? super E> listener) {
p.addListener(listener);
}
#Override
public void removeListener(ChangeListener<? super E> listener) {
p.removeListener(listener);
}
#Override
public void addListener(InvalidationListener listener) {
p.addListener(listener);
}
#Override
public void removeListener(InvalidationListener listener) {
p.removeListener(listener);
}
#Override
public Object getBean() {
return p.getBean();
}
#Override
public String getName() {
return p.getName();
}
#Override
public void bind(ObservableValue<? extends E> observable) {
p.bind(observable);
externalBound = true;
}
#Override
public void unbind() {
p.unbind();
externalBound = false;
set(get()); //to reactivate the extractor on the last value
}
#Override
public boolean isBound() {
return externalBound;
}
}
I think you need to add a listener to your object. This can be done simply. First of all you should write your class with a constructor and with getters this way:
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
public class SomeType {
public ObjectProperty<TestProperty> property;
public SomeType(TestProperty testProperty) {
this.property = new SimpleObjectProperty<>(testProperty);
}
public TestProperty getProperty() {
return property.get();
}
public ObjectProperty<TestProperty> propertyProperty() {
return property;
}
}
Then anywhere you have an instance of SomeType you can chain the properties, so you get the property the property's testProperty() and then simply add a listener to it.
someType.getProperty().testProperty().addListener((observable, oldValue, newValue) -> {
// Do whatever you want if the its value changed.
// You can also use its old or new value.
});
This is my first post here, so I hope this question isn't a duplicate. I'm a hobbyist who is trying to use JavaFX to create an application which can manage a debating tournament.
I want to create a Singleton object in TournamentCreation, which TournamentEditor can also access and manipulate.
It seems that when my Singleton GlobalInstance object is created (which holds a tournament inside it that can be accessed and edited from elsewhere), a NullPointerException is thrown. Using debugging I've managed to figure out that it is occurring when GlobalInstance calls the default Tournament constructor.
Code time. Here is the TournamentCreationController where the error begins with the line GlobalInstance.getInstance().currentTournament().setRounds(roundsIn);
import java.net.URL;
import java.util.ResourceBundle;
import BusinessLogic.GlobalInstance;
import javafx.collections.FXCollections;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.ChoiceBox;
import javafx.scene.control.TextField;
public class TournamentCreationController implements Initializable , ControlledScreen {
ScreensController myController;
#FXML
TextField nameChooser;
#FXML
ChoiceBox roundNumberChooser;
#FXML
ChoiceBox breakNumberChooser;
#FXML
ChoiceBox noviceBreakNumberChooser;
#FXML
ChoiceBox eslBreakNumberChooser;
#FXML
ChoiceBox proAmBreakNumberChooser;
/**
* Initializes the controller class.
*/
#Override
public void initialize(URL url, ResourceBundle rb)
{
roundNumberChooser.setItems(FXCollections.observableArrayList(1,2,3,4,5,6,7,8,9));
roundNumberChooser.getSelectionModel().select(4);
breakNumberChooser.setItems(FXCollections.observableArrayList(4,8,16,32,64));
breakNumberChooser.getSelectionModel().selectFirst();
noviceBreakNumberChooser.setItems(FXCollections.observableArrayList(0,4,8,16,32,64));
noviceBreakNumberChooser.getSelectionModel().selectFirst();
eslBreakNumberChooser.setItems(FXCollections.observableArrayList(0,4,8,16,32,64));
eslBreakNumberChooser.getSelectionModel().selectFirst();
proAmBreakNumberChooser.setItems(FXCollections.observableArrayList(0,4,8,16,32,64));
proAmBreakNumberChooser.getSelectionModel().selectFirst();
}
public void setScreenParent(ScreensController screenParent)
{
myController = screenParent;
}
#FXML
private void goToEditor(ActionEvent event)
{
String nameIn = nameChooser.getText();
int roundsIn = (int)roundNumberChooser.getSelectionModel().getSelectedItem();
int openBreakTeamsIn = (int)breakNumberChooser.getSelectionModel().getSelectedItem();
int eslBreakTeamsIn = (int)eslBreakNumberChooser.getSelectionModel().getSelectedItem();
int noviceBreakTeamsIn = (int)noviceBreakNumberChooser.getSelectionModel().getSelectedItem();
int proAmBreakTeamsIn = (int)proAmBreakNumberChooser.getSelectionModel().getSelectedItem();
GlobalInstance.getInstance().currentTournament().setRounds(roundsIn);
GlobalInstance.getInstance().currentTournament().setOpenBreakTeams(openBreakTeamsIn);
GlobalInstance.getInstance().currentTournament().setESLBreakTeams(eslBreakTeamsIn);
GlobalInstance.getInstance().currentTournament().setNoviceBreakTeams(noviceBreakTeamsIn);
GlobalInstance.getInstance().currentTournament().setProAmBreakTeams(proAmBreakTeamsIn);
myController.setScreen(ScreensFramework.screen4ID);
}
}
And here is the Singleton class:
public class GlobalInstance
{
private final static GlobalInstance instance = new GlobalInstance();
private Tournament tournament = new Tournament();
public static GlobalInstance getInstance()
{
return instance;
}
public Tournament currentTournament()
{
return tournament;
}
}
And finally here is the Tournament class (ignore most of it, the exact error occurs at name.set("name") in the default constructor):
import javafx.beans.property.BooleanProperty;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.StringProperty;
public class Tournament
{
private StringProperty name;
private IntegerProperty rounds;
private BooleanProperty eslBreak;
private BooleanProperty noviceBreak;
private BooleanProperty proAmBreak;
private IntegerProperty openBreakTeams;
private IntegerProperty eslBreakTeams;
private IntegerProperty noviceBreakTeams;
private IntegerProperty proAmBreakTeams;
public Tournament()
{
name.set("name");
rounds.set(0);
eslBreak.set(false);
noviceBreak.set(false);
proAmBreak.set(false);
openBreakTeams.set(4);
eslBreakTeams.set(0);
noviceBreakTeams.set(0);
proAmBreakTeams.set(0);
}
public Tournament(String nameIn, int roundsIn, int openBreakTeamsIn, int eslBreakTeamsIn, int noviceBreakTeamsIn, int proAmBreakTeamsIn)
{
name.set(nameIn);
rounds.set(roundsIn);
openBreakTeams.set(openBreakTeamsIn);
if(eslBreakTeamsIn==0)
{
eslBreak.set(false);
eslBreakTeams.set(0);
}
else
{
eslBreak.set(true);
eslBreakTeams.set(eslBreakTeamsIn);
}
if(noviceBreakTeamsIn==0)
{
noviceBreak.set(false);
noviceBreakTeams.set(0);
}
else
{
noviceBreak.set(true);
noviceBreakTeams.set(noviceBreakTeamsIn);
}
if(proAmBreakTeamsIn==0)
{
proAmBreak.set(false);
proAmBreakTeams.set(0);
}
else
{
proAmBreak.set(true);
proAmBreakTeams.set(noviceBreakTeamsIn);
}
}
public String getName()
{
return name.get();
}
public void setName(String nameIn)
{
name.set(nameIn);
}
public int getRounds()
{
return rounds.get();
}
public void setRounds(int roundsIn)
{
rounds.set(roundsIn);
}
public int getOpenBreakTeams()
{
return openBreakTeams.get();
}
public void setOpenBreakTeams(int openBreakTeamsIn)
{
openBreakTeams.set(openBreakTeamsIn);
}
public boolean getESLBreak()
{
return eslBreak.get();
}
public int getESLBreakNumber()
{
return eslBreakTeams.get();
}
public void setESLBreakTeams(int eslBreakTeamsIn)
{
if (eslBreakTeamsIn==0)
{
eslBreak.set(false);
eslBreakTeams.set(0);
}
else
{
eslBreak.set(true);
eslBreakTeams.set(eslBreakTeamsIn);
}
}
public boolean getNoviceBreak()
{
return noviceBreak.get();
}
public int getNoviceBreakNumber()
{
return noviceBreakTeams.get();
}
public void setNoviceBreakTeams(int noviceBreakTeamsIn)
{
if (noviceBreakTeamsIn==0)
{
noviceBreak.set(false);
noviceBreakTeams.set(0);
}
else
{
noviceBreak.set(true);
noviceBreakTeams.set(noviceBreakTeamsIn);
}
}
public boolean getProAmBreak()
{
return proAmBreak.get();
}
public int getProAmBreakNumber()
{
return proAmBreakTeams.get();
}
public void setProAmBreakTeams(int proAmBreakTeamsIn)
{
if (proAmBreakTeamsIn==0)
{
proAmBreak.set(false);
proAmBreakTeams.set(0);
}
else
{
proAmBreak.set(true);
proAmBreakTeams.set(proAmBreakTeamsIn);
}
}
}
While programming, the error messages are the best helpers for resolving issues. In Java, the root cause of exception can tell the actual problem. So if we look at your use case,
Caused by: java.lang.ExceptionInInitializerError
at TabIt.TournamentCreationController.goToEditor(TournamentCreationController.java:84)
tells us, the error occurred in goToEditor() method at line 84 of TournamentCreationController class. Then if we continue to read the rest of exception tracktrace message, we see the actual root error (cause) of it,
Caused by: java.lang.NullPointerException
at BusinessLogic.Tournament.<init>(Tournament.java:24)
Here it is saying that the type of error is NullPointerException and is at line 24 of Tournament class.
These hints are enough to determine the problem.
UPDATE
Based on your updated question, the problem is that name variable is not initialized yet. Trying to use uninitialized object throws null pointer exception. the Tournament's constructor should be:
public Tournament()
{
name = new SimpleStringProperty("name");
rounds = new SimpleIntegerProperty(0);
eslBreak = new SimpleBooleanProperty(false);
// etc.
}
public Tournament(String nameIn, int roundsIn, int openBreakTeamsIn, int eslBreakTeamsIn, int noviceBreakTeamsIn, int proAmBreakTeamsIn)
{
name = new SimpleStringProperty(nameIn);
rounds = new SimpleIntegerProperty(roundsIn);
eslBreak = new SimpleBooleanProperty(openBreakTeamsIn);
// etc.
}
I am trying to get the table cells to show the string when i create new rows. But all the rows are just empty. Do anyone know what i am doing wrong?
Here is the main class:
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Cursor;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class Main extends Application {
#Override
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("/fxml/BasketCase_GUI_0.3.fxml"));
Scene scene = new Scene(root,1110,740);
scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
primaryStage.setResizable(false);
primaryStage.setScene(scene);
primaryStage.setTitle("Basket Case_Beta");
primaryStage.show();
scene.setCursor(Cursor.DEFAULT);
}
public static void main(String[] args) throws Exception {
launch(args);
}
}
This is normal and working so i dont think you need to worry about that one.
Here is the controller class. Where I think the problem might be.
package application;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
public class MainController implements Initializable {
#FXML
TableView<Table> TableID;
#FXML
TableColumn<Table, Integer> aPlayerID;
#FXML
TableColumn<Table, String> aLeague;
#FXML
TableColumn<Table, String> aName;
private int aNumber = 1;
SimpleStringProperty str = new SimpleStringProperty();
public MainController() {
str.set("Hello");
}
final ObservableList<Table> data = FXCollections.observableArrayList(
new Table(aNumber++, "hehe", "hoho"),
new Table(aNumber++, "hehe", "hoho"),
new Table(aNumber++, "hehe", "hoho")
);
public void buttonClick(ActionEvent event) {
data.add(new Table(aNumber++, "hehe", "hoho"));
TableID.getColumns().addAll(aPlayerID, aLeague, aName);
}
#Override
public void initialize(URL arg0, ResourceBundle arg1) {
aPlayerID.setCellValueFactory( new PropertyValueFactory<Table, Integer>("bPlayerID"));
aLeague.setCellValueFactory( new PropertyValueFactory<Table, String>("bLeague"));
aName.setCellValueFactory( new PropertyValueFactory<Table, String>("bName"));
TableID.setItems(data);
}
}
And here is also the table class thats needed for the tableviewer
package application;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
public class Table {
private final SimpleIntegerProperty bPlayerID;
private final SimpleStringProperty bLeague;
private final SimpleStringProperty bName;
public Table(int cPlayerID, String cLeague, String cName) {
this.bPlayerID = new SimpleIntegerProperty(cPlayerID);
this.bLeague = new SimpleStringProperty(cLeague);
this.bName = new SimpleStringProperty(cName);
}
public int getbPlayerID() {
return bPlayerID.get();
}
public void setbPlayerID(int v) {
bPlayerID.set(v);
}
public String getbLeague() {
return bLeague.get();
}
public void setbLeague(String v) {
bLeague.set(v);
}
public String getbName() {
return bName.get();
}
public void setbName(String v) {
bName.set(v);
}
}
Do you guys know what could be wrong or maybe suggest how I could add just the tableviewer with code that still works with the rest of the fxml file from the scenebuilder?
The names of your get methods are wrong. According to the PropertyValueFactory documentation, if you pass in a property name of "xyz", the property value factory will first look for a method xyzProperty() belonging to the object in the table row. If it doesn't find that, it will fall back on looking for a method called getXyz() (carefully look at the capitalization there), wrapping the result in a ReadOnlyObjectWrapper.
So the following would work:
package application;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
public class Table {
private final SimpleIntegerProperty bPlayerID;
private final SimpleStringProperty bLeague;
private final SimpleStringProperty bName;
public Table(int cPlayerID, String cLeague, String cName) {
this.bPlayerID = new SimpleIntegerProperty(cPlayerID);
this.bLeague = new SimpleStringProperty(cLeague);
this.bName = new SimpleStringProperty(cName);
}
public int getBPlayerID() {
return bPlayerID.get();
}
public void setBPlayerID(int v) {
bPlayerID.set(v);
}
public String getBLeague() {
return bLeague.get();
}
public void setBLeague(String v) {
bLeague.set(v);
}
public String getBName() {
return bName.get();
}
public void setBName(String v) {
bName.set(v);
}
}
However, as stated in the PropertyValueFactory documentation, the properties in this case would not be "live": in other words if the values change, the table will not automatically update. Additionally, if you wanted to make the table editable, it wouldn't update the properties without some explicit wiring to call the set methods.
It's better to define your table model using the outline in the Properties and Bindings tutorial:
package application;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
public class Table {
private final IntegerProperty bPlayerID;
private final StringProperty bLeague;
private final StringProperty bName;
public Table(int cPlayerID, String cLeague, String cName) {
this.bPlayerID = new SimpleIntegerProperty(cPlayerID);
this.bLeague = new SimpleStringProperty(cLeague);
this.bName = new SimpleStringProperty(cName);
}
public int getBPlayerID() {
return bPlayerID.get();
}
public void setBPlayerID(int v) {
bPlayerID.set(v);
}
public IntegerProperty bPlayerIDProperty() {
return bPlayerID ;
}
public String getBLeague() {
return bLeague.get();
}
public void setBLeague(String v) {
bLeague.set(v);
}
public StringProperty bLeagueProperty() {
return bLeague ;
}
public String getBName() {
return bName.get();
}
public void setBName(String v) {
bName.set(v);
}
public StringProperty bNameProperty() {
return bName ;
}
}
If you do that, then (in Java 8) you can use the following cell value factories, instead of the PropertyValueFactory:
aPlayerID.setCellValueFactory(cellData -> cellData.getValue().bPlayerIDProperty());
which will allow the compiler to catch any errors, instead of it just failing silently at runtime.
in stringproperty you gotto add asobjects() method after cellData.getValue().bPlayerIDProperty())... so I hope that would help