hu.akarnokd.reactive4java.util

Class HybridSubject<T>

java.lang.Object

java.util.Observable

hu.akarnokd.reactive4java.util.HybridSubject<T>

Type Parameters:

T - the value type

All Implemented Interfaces:

BaseObserver, CloseableObservable<T>, Observable<T>, Observer<T>, Subject<T,T>, java.io.Closeable, java.lang.AutoCloseable

public class HybridSubject<T>
extends java.util.Observable
implements java.util.Observer, Subject<T,T>, CloseableObservable<T>

A combination of the java and reactive observable and observer classes and interfaces.

Note that since java-observer is not generic, update() calls are cast to type T and might cause ClassCastException in case the data traveling is incorrect.

If the reactive-observer receives an error or finish event, all sub-observers are notified and both kinds of observers are unregistered.

Note also that reactive-observers are not notified in registration order and mixed observer case, only the java-observers are notified in order after the notification of reactive-observers.

Since:

0.97

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.concurrent.ConcurrentMap<java.io.Closeable,Observer<? super T>>	registry The registration holder for the reactive-observers.

Constructor Summary

Constructors

Constructor and Description
HybridSubject()

Method Summary

Modifier and Type	Method and Description
void	addObserver(Observer<? super T> observer) Registers the reactive-observer with this observable.
void	close()
int	countObservers()
void	deleteObserver(Observer<? super T> observer) Deregisters all instances of the supplied observer.
void	deleteObservers()
void	error(java.lang.Throwable ex) An exception is received.
void	finish() No more values to expect.
void	next(T value) The next value is received.
void	notifyObservers(java.lang.Object arg)
protected java.util.List<Observer<? super T>>	observers()
java.io.Closeable	register(java.util.Observer observer) Registers a java-observer and returns a handle to it.
java.io.Closeable	register(Observer<? super T> observer) Registers an observer for the notification of Ts.
protected void	unregister(java.io.Closeable handle) Unregister the given observer by its handle.
void	update(java.util.Observable o, java.lang.Object arg)

Methods inherited from class java.util.Observable

addObserver, clearChanged, deleteObserver, hasChanged, notifyObservers, setChanged

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

registry

@Nonnull
protected java.util.concurrent.ConcurrentMap<java.io.Closeable,Observer<? super T>> registry

The registration holder for the reactive-observers.

Constructor Detail

HybridSubject

public HybridSubject()

Method Detail

next

public void next(T value)

Description copied from interface: Observer

The next value is received.

Specified by:

next in interface Observer<T>

Parameters:

value - the next value

notifyObservers

public void notifyObservers(java.lang.Object arg)

Overrides:

notifyObservers in class java.util.Observable

error

public void error(@Nonnull
                  java.lang.Throwable ex)

Description copied from interface: BaseObserver

An exception is received.

Specified by:

error in interface BaseObserver

Parameters:

ex - the exception

finish

public void finish()

Description copied from interface: BaseObserver

No more values to expect.

Specified by:

finish in interface BaseObserver

observers

@Nonnull
protected java.util.List<Observer<? super T>> observers()

Returns:

a snapshot of the registered observers.

register

@Nonnull
public java.io.Closeable register(@Nonnull
                                            Observer<? super T> observer)

Description copied from interface: Observable

Registers an observer for the notification of Ts.

Specified by:

register in interface Observable<T>

Parameters:

observer - the observer of Ts or any supertype of it

Returns:

the way of deregister the observer from this provider

register

public java.io.Closeable register(@Nonnull
                                  java.util.Observer observer)

Registers a java-observer and returns a handle to it. The observer can be unregistered via this handle or the regular deleteObserver().

The convenience method is to have symmetric means for both observer kinds to interact with this observable.

Parameters:

observer - the observer to register

Returns:

the unregistration handle

unregister

protected void unregister(@Nonnull
                          java.io.Closeable handle)

Unregister the given observer by its handle.

Parameters:

handle - the handle identifying the observer

update

public void update(java.util.Observable o,
                   java.lang.Object arg)

deleteObservers

public void deleteObservers()

Overrides:

deleteObservers in class java.util.Observable

close

public void close()

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

countObservers

public int countObservers()

Overrides:

countObservers in class java.util.Observable

addObserver

public void addObserver(@Nonnull
                        Observer<? super T> observer)

Registers the reactive-observer with this observable.

The convenience method is to have symmetric means for both observer kinds to interact with this observable.

Parameters:

observer - the reactive-observer to register

deleteObserver

public void deleteObserver(@Nonnull
                           Observer<? super T> observer)

Deregisters all instances of the supplied observer.

Note that reactive-registration allows multiple registration and deregistration for the same observer instance, which are treated independently whereas java-observable does not.

The convenience method is to have symmetric means for both observer kinds to interact with this observable.

Parameters:

observer - the reactive-observer to unregister