interface A {
public void eg1();
}
interface B {
public void eg1();
}
public class SomeOtherClassName implements A, B {
#Override
public void eg1() {
System.out.println("test.eg1()");
}
}
What is the output and what occurs if method is overriden in interface?
First of all it's of no use to implement both class A and B as both
of them has same method signature i.e both has same method name and
return type.
Secondly you'll need a main method to run the program.
Also in interface you can only declare the methods, the implementation
has to be done in the class which implements it.
interface A {
public void eg1();
}
interface B {
public void eg1();
}
public class Test implements A{
#Override
public void eg1() {
System.out.println("test.eg1()");
}
public static void main (String args[]) {
A a = new test();
a.eg1();
}
}
Output : test.eg1()
Related
Suppose I am having below interface inside binary jar:
public interface OrderDemo
{
public void add();
public void shut();
public void manage();
}
When I am adding this as Jar as part of dependency in my project in eclipse after implementing OrderDemo interface order of method get changed.
public class Demo implements OrderDemo
{
#Override
public void add();
{
}
#Override
public void manage()
{
}
#Override
public void shut()
{
}
}
Tried option given in eclipse preference but won't work.
I am currently dispatching my Business Logic via the Concurrency API JavaFX offers. But there is one part I stumble over which does not feel clean to me.
Basically if you create a Service which may look like this
public class FooCommand extends Service<Foo> {
#Override protected Task<Foo> createTask() {
return new Foo();
}
}
and I set the onSucceeded
FooCommand fooCommand = CommandProvider.get(FooCommand.class);
fooCommand.setOnSucceeded(new FooSucceededHandler());
fooCommand.start();
to an instance of this class
public class FooSucceededHandler implements EventHandler<WorkerStateEvent> {
#Override public void handle(WorkerStateEvent event) {
Foo f = (Foo) event.getSource().getValue();
}
}
But as you can see I need to cast the value of the Worker to (Foo). Is there some cleaner way to do it?
You could just make your own abstract class:
public abstract class EventCallback<T> implements EventHandler<WorkerStateEvent> {
#Override
public void handle(final WorkerStateEvent workerStateEvent) {
T returnType = (T) workerStateEvent.getSource().valueProperty().get();
this.handle(returnType);
}
public abstract void handle(T objectReturned);
}
And then using it:
final EventCallback<MonType> eventCallback = new EventCallback<MonType>() {
#Override
public void handle(final MonType objectReturned) {
// DO STUFF
}
};
As it is also an EventHandler, it is compatible with JavaFX concurrent API.
I have a problem with #IocProvider (), annotation does not work.
The code is very similar to https://docs.jboss.org/author/display/ERRAI/Container+Wiring
public interface Test {
String getGreeting();
}
#ApplicationScoped
public class TestImpl implements Test {
public String getGreeting() {
return "Hello:)";
}
}
#IOCProvider
#Singleton
public class TestProvider implements Provider<Test> {
#Override
public Test get() {
return new TestImpl();
}
}
Then I want use DI in my broadcast service (errai-bus).
#Service
public class BroadcastService implements MessageCallback {
#Inject
Test test;
#Inject
MessageBus bus;
#Inject
public BroadcastService(MessageBus bus) {
this.bus = bus;
}
public void callback(Message message) {
MessageBuilder.createMessage()
.toSubject("BroadcastReceiver")
.with("BroadcastText", test.getGreeting()).errorsHandledBy(new ErrorCallback() {
#Override
public boolean error(Message message, Throwable throwable) {
return true;
}
}).sendNowWith(bus);
}
}
I get a error:
1) No implementation for com.gwtplatform.samples.basic.server.Test was bound.
while locating com.gwtplatform.samples.basic.server.Test
for field at com.gwtplatform.samples.basic.server.BroadcastService.test(BroadcastService.java:32)
at org.jboss.errai.bus.server.service.ServiceProcessor$1.configure(ServiceProcessor.java:118)
If I change the code to
#Inject
TestImpl test;
It works, but I need the provider. Do you have some idea?
Because you're trying to use #IOCProvider in server-side code. Errai IOC is completely client-side.
I am new to RhinoMocks, and I am trying to write a test as shown
I have classes like these
public class A
{
public void methodA(){}
}
public class B
{
public void methodB(A a)
{
a.methodA();
}
}
And i am trying to test it like this
A a = MockRepository.GenerateMock<A>();
public void ShouldTest()
{
B b = new B();
b.methodB(a);
a.AssertWasCalled(x=>x.methodA());
a.VerifyAllExpectations();
}
But it is giving the error as shown:
System.InvalidOperationException : No expectations were setup to be verified, ensure that the method call in the action is a virtual (C#) / overridable (VB.Net) method call.
How do I test methodB then?? Can someone help??
Rhino mock creates proxy class when you call MockRepository.Generate *** method. This means that it extends your type. If you don't declare any abstraction you cannot make any derivation which is essential in any mocking framework.
You can do two things
Create an interface (better design)
Make the member virtual (this will allow RhinoMocks to derive from your type and create a proxy for the virtual member
Sample code
public interface IA { void methodA();}
public class A:IA{public void methodA() { }}
public class B
{
public void methodB(IA a)
{
a.methodA();
}
}
[TestFixture]
public class Bar
{
[Test]
public void BarTest()
{
//Arrange
var repo = MockRepository.GenerateMock<IA>();
//Act
B b = new B();
b.methodB(repo);
//Assert
repo.AssertWasCalled(a => a.methodA());
repo.VerifyAllExpectations();
}
}
You have concrete classes with no virtual methods and no interfaces. You can't mock anything.
Update:
Here's one way to do it:
public interface IA
{
void methodA();
}
public class A : IA
{
public void methodA(){}
}
public class B
{
public void methodB(IA a)
{
a.methodA();
}
}
Then use
IA a = MockRepository.GenerateMock<IA>();
I have something like this:
request.findAllProjects().fire(new ExtReceiver<List<ProjectProxy>>() {
#Override
public void onSuccess(List<ProjectProxy> response) {
view.setProjects(response);
}
});
It is anonymous inner class of the abstract class ExtReceiver. The ExtReceiver is for handling the errors with an errorHandler which i want to provide.
public abstract class ExtReceiver<T> extends Receiver<T> {
private ErrorHandler errorHandler;
public ExtReceiver() {
}
#Inject
public void setErrorHandler(ErrorHandler errorHandler)
{
this.errorHandler = errorHandler;
}
#Override
public abstract void onSuccess(T response);
#Override
public void onFailure(ServerFailure error) {
errorHandler.exception(error);
}
#Override
public void onViolation(Set<Violation> errors) {
ValidationUtils.processViolation(errors);
}
}
I understand why this can't work, because i use the new Operator. But how could i do something like this. I want to have that anonymous class and not put it in an own file or something.
How could I inject that errorHandler? Thought about staticInjections, but it looked like this does not work too (Maybe because of the inheritance i create with doing an anonymous class)
In the opposite to normal Guice i don't know an injector.getInstance() call.
For information: That is a requestFactory call
Why don't you put the errorHandler parameter into the constructor of your abstract class instead creating a separate setErrorHandler setter, something like this:
public abstract class ExtReceiver<T> extends Receiver<T> {
private ErrorHandler errorHandler;
#Inject
public ExtReceiver(ErrorHandler errorHandler) {
this.errorHandler = errorHandler;
}
}
Declare the bindings:
public class MyClientModule extends AbstractGinModule {
protected void configure() {
bind(ErrorHandler.class).in(Singleton.class);
}
}
Declare a Ginjector for your ErrorHandler class annotating it with the Module:
#GinModules(MyClientModule.class)
public interface MyErrorHandlerInjector extends Ginjector {
ErrorHandler getErrorHandler();
}
and then use it like this:
MyErrorHandlerGinjector injector = GWT.create(MyErrorHandlerGinjector.class);
ErrorHandler errorHandler = injector.getErrorHandler();
request.findAllProjects().fire(new ExtReceiver<List<ProjectProxy>>(errorHandler) {
#Override
public void onSuccess(List<ProjectProxy> response) {
view.setProjects(response);
}
});
I think this should work.