The use of timer messages

Timers in nyssr.net are messages that are sent to their target after a certain time. They can be sent repeatedly, and they can transport user data.

As always, we assume that the package has been initialized. Here are the dependencies we have:

@Override
public void getDependencies(@NotNull final IServiceDependencyList aDependencyList)
{
    aDependencyList.add(INamespaceRegistry.class);
    aDependencyList.add(ITimerManager.class);
}

We need the namespace registry to fetch a namespace in which we can register the target. For the timer we need the Timer Manager.

class CMyTarget extends CTarget implements IService
{
    private static final IId MY_TIMER_ID = CIdFactory.fromObject("MyTimerId");
    private static final long TIMEOUT = 1000L;
    private final IDependencies mDependencies;
    // can be used to stop or restart timer
    private long mTimerHandle = ITimerManager.INVALID;

    CMyTarget(@NotNull final IDependencies aDependencies)
    {
        mDependencies = aDependencies;

        addMessageHandler(CRecordStartTarget.ID,
                          this::asyncStartTarget);
        // add message handler for timer
        addMessageHandler(MY_TIMER_ID,
                          this::asyncTimer);
    }

    private boolean asyncStartTarget(@NotNull final CEnvelope aEnvelope,
                                     @NotNull final CRecord aRecord)
    {
        // In the SYSTEM namespace thread
        // start Timer
        mTimerHandle = mDependencies.getTimerManager()
                                    .createAndStartTimer(MY_TIMER_ID,
                                                         getAddress(),
                                                         TIMEOUT,
                                                         false,
                                                         null);

        aEnvelope.setResultSuccess();
        return true;
    }

    // handle Timer
    private boolean asyncTimer(@NotNull final CEnvelope aEnvelope,
                               @NotNull final CRecord aRecord)
    {
        // do something
        aEnvelope.setResultSuccess();
        return true;
    }

    @Override
    public void activate(@NotNull final IServiceRegistry aServiceRegistry) throws Exception
    {
        final INamespace namespace = mDependencies.getNamespaceRegistry()
                                                  .getNamespace(CWellKnownNID.SYSTEM);
        assert namespace != null;
        namespace.getTargetRegistry()
                 .registerTarget(this);
    }

    @Override
    public void deactivate(@NotNull final IServiceRegistry aServiceRegistry) throws Exception
    {
        deregisterTarget();
    }
}