Interfaces of Rx

Observable.java

public interface Observable<T> {
 
 public Subscription subscribe(Observer<T> observer);
 
}

Observer.java

public interface Observer<T> {

    /**
     * Notifies the Observer that the {@link Observable} has finished sending push-based notifications.
     * <p>
     * The {@link Observable} will not call this closure if it calls <code>onError</code>.
     */
    public void onCompleted();

    /**
     * Notifies the Observer that the {@link Observable} has experienced an error condition.
     * <p>
     * If the {@link Observable} calls this closure, it will not thereafter call <code>onNext</code> or <code>onCompleted</code>.
     * 
     * @param e
     */
    public void onError(Exception e);

    /**
     * Provides the Observer with new data.
     * <p>
     * The {@link Observable} calls this closure 1 or more times, unless it calls <code>onError</code> in which case this closure may never be called.
     * <p>
     * The {@link Observable} will not call this closure again after it calls either <code>onCompleted</code> or <code>onError</code>.
     * 
     * @param args
     */
    public void onNext(T args);
}

Subscription.java

public interface Subscription {

    /**
     * Stop receiving notifications on the {@link Observer} that was registered when this Subscription was received.
     * <p>
     * This allows unregistering an {@link Observer} before it has finished receiving all events (ie. before onCompleted is called).
     */
    public void unsubscribe();

}