I have a bundle test.Bundle1 that have some properties fulfilled by Blueprint injections.
I've created one test fragment whose Host is test.Bundle1 and I would like to obtain myClassA instantiated singleton to access those properties.
I know that I could acess the bundle from a class name using FrameworkUtil.getBundle(), but I don't know how to get the instance of this class.
How could I do that?
thanks
Cristiano
One way to go about this is to simply publish that instance as a service, so you can look it up in code that needs it.
Related
I have an interface which I have implemented. I have annoted the impl with #Component and #Service of the package org.apache.felix.scr.annotations.
I wrote a simple constructor for my impl
public MyImpl(){
LOG.info("New instance created!!");
}
I also added loggers in #activate and #deactivate method.
I expected to see "New instance created!!" only once BUT I can see activate and deactivate method being called per request I make on a page(This service is invoked by A Sling Model which is used in that page)
What I saw was "New instance created!!" logged several times.
This means the OSGi container create multiple instances of my Service and called the activate and deactivate method every time.
This shows that this is not a Singleton.
The Object should be discarded only when I uninstall my bundle.
Please help me understand what is going on here.
I WANT TO IMPLEMENT A TRUE SINGLETON IN AEM
I have implemented this in AEM 6.5 instance which uses Apache Felix.
Edit:
Adding Service properties:
aemRootUrl http://localhost:8080
api.http.connections_manager.timeout 60000
api.http.cookie_max.age 18000
api.http.max_connections 200
api.http.max_connections_per_host 20
api.http.timeout.connection 300000
api.http.timeout.socket 300000
api.server.ssl.trust_all_certs true
api.server.url https://10asdasdsad
api.server.username admin
component.id 3925
component.name com.example.foundation.core.connection.impl.HybrisConnectionImpl
non_akamai.api.server.url hadasdadasd
service.bundleid 585
Service PID com.example.foundation.core.connection.impl.HybrisConnectionImpl
service.scope bundle
Using Bundles com.example.dumb-foundation.core (585)
Values altered to hide client specific information
EDIT::
I've removed the SCR annotations and replaced them with OSGI annotations here I've explictly specified
#Component(service =HybrisConnection.class, immediate=true,scope = ServiceScope.SINGLETON)
But still is shows as scope=bundle.
Should I enforce Singleton and OSGi annotations on it's dependencies as well for this to be a proper Singleton?
In declarative services (which is what you use behind the scenes) there are some cases when a component (and its service) is unpublished.
By default a simple component with immediate=true will come up when the bundle starts and go down when it stops.
If your component has any mandatory service dependencies (#Reference) then it will only be active while all dependencies are present. So if at least one dependent service goes away the component will be deactivated.
In addition the component might get restarted when config is not present at start but added later. If you want to avoid this make the config required.
Every thing #Christian Schneider said is true.
They AEM services are Singletons but are deactivated/unpublished at times. This might be for various reasons.
I faced a horrible issue because of ConfigurationAdmin service. Using this services caused our OSGi config files to be bound to the wrong bundle i.e. SlingModels. bundle within AEM.
the only way to access this is by getting the service using configAdmin.getConfig(PID).setBundleLocation(null);
BUT Doing this causes the service that is linked to this configuration to restart.
So every time I did config.setBundleLocation(null) the service restarted.
The best and most awesome way to resolve this is use OCD to define configuration for OSGi Services linked to OSGi config.xmls
AND NEVER EVER EVER use configuration Admin
If you want to access properties of another service Say ServiceA want to read ServiceB's title property set in com.example.serivce.impl.ServiceB.xml
Then in ServiceB in the #activate method read the props from OCD config and set it in instance level and have ServiceA inject ServiceB as it's dependency and use the property needed.
eg.
class ServiceA{
#Reference
private ServiceB serviceB;
public void someMethod(){
serviceB.getTitle(); // Successfully read property of another service i.e.
ServiceB without using ConfigurationAdmin.
}
}
I'm trying to implement integration testing in my app and have test class like that:
#ExtendWith(value={MyDockerExtension.class})
#ExtendWith(value={SpringExtension.class})
#WebAppConfiguration
#ContextConfiguration(classes={...})
#TestInstance(TestInstance.LifeCycle.PER_CLASS)
public class TestClass{ ... }
Is there any way to make MyDockerExtension execute some code, before whole SpringExtension start working and generate whole Context with Configurationc classes?
I've heard that order in which we declare extensions is the key, but sadly MyDockerExtension that implements BeforeAllCallback, AfterAllCallback executes right before test method and after whole context is loaded. In that situation it's to late to start containers with docker, becuase since whole context is loaded my app already tried to connect to the container.
At first I was skeptical about the order being fixed but you're correct:
Extensions registered declaratively via #ExtendWith will be executed in the order in which they are declared in the source code.
Regarding the MyDockerExtension, you may want to look at the extension point TestInstancePostProcessor, which is called before #BeforeAll. SpringExtension implements it and I guess it's there where it sets up the application context. If you also implement it, you should be able to act before it does.
I am currently deploying my custom controls as OSGi plugins and I wanted to do the same thing with my beans. I have tried putting them into the OSGi plugin and it works fine but the only problem I have is the faces-config.
It seems it has to be called faces-config in the OSGi plugin to work but that means i can't use beans in the NSF anymore because it seems to ignore the local faces-config.
Is there a way to change the name of the faces-config in the OSGi plugin?
Something like FEATURE-faces-config.xml?
In the class in your plugin that extends AbstractXspLibrary, you can override "getFacesConfigFiles", which should return an array of strings representing paths within the plugin to additional files of any name to load as faces-config additions. For example:
#Override
public String[] getFacesConfigFiles() {
return new String[] {
"com/example/config/beans.xml"
};
}
Then you can put the config file in that path within your Java source folder (or another folder that is included in build.properties) and it will be loaded in addition to your app's normal faces-config, beans and all.
The NSFs are running as separate, distinct Java applications. The OSGi plugin is running in the OSGi layer, above all those distinct Java applications, as a single code base. Consequently, the faces-config is only at that level.
It's possible to load them dynamically, by using an ImplicitObjectFactory, loaded from an XspContributor. That's what is done in OpenNTF Domino API for e.g. userScope (which is a bean stored in applicationScope of an NSF). See org.openntf.domino.xsp.helpers.OpenntfDominoImplicitObjectFactory, which is referenced in OpenntfDominoXspContributor, loaded via the extension point of type "com.ibm.xsp.library.Contributor".
A few caveats:
You have no control over what happens if you try to register your bean with a name the developer also uses for a different variable in that scope.
Unless you add code to check if the library is enabled, as we do, you'll be adding the bean to every database on the server.
You still need to add the library to the NSF. Unless you also provide a component that those databases will all use, there's no way you can programmatically add it, as far as I know.
It might be easier to skip the bean approach and just add an instance of the Java class in beforePageLoad, page controller class, or however you're managing the backing to the relevant XPage (if viewScope) or application (if sessionScope / applicationScope).
Let's imagine a bundle in which exists:
A component is responsible of listen all "Device" service instances in the service registry.
The same component needs an "adaptor factory" in order to create "Adaptors" by using the discovered devices.
The factory is owned by another bundle.
I can solve part of the problem by using a ServiceTracker (Activator + Service Tracker): the activator instantiates the ServiceTraker and it can register all changes in "Device" services.
But i can't inject to this service tracker the DS factory created in other bundle, because it will result in two instances (one created by activator AND without the member /// another created by osgi AND with member variable ok but can't listen the "Device" service changes).
So... how can i solve this scenario? How can i have a Service Tracker (perfect for me) with a DS as a class member?
Use no Activator, instead use a component or service (we will call it A) with a declarative services 'activate(ComponentContext)' method. Within the activate method, you can instantiate your ServiceTracker like normal.
When you instantiate the ServiceTracker within A's activate method, you can also pass in the AdapterFactory into the ServiceTracker. You can get the AdapterFactory by pulling it out of the BundleContext taken from ComponentContext or (even better) use DS and make it a service reference to your A component.
That said: why do you need ServiceTracker for this? Unless I misunderstand, you can use DS bind and unbind to receive events on the availability of a Service.
EDIT: An (OLD) example of Bind/Unbind behavior using multiple cardinality: http://blog.tfd.co.uk/2009/11/12/declarative-optional-multiple-references-flaky-in-osgi/
EDIT: A comparision of the two approaches but doesn't go into bind/unbind so much: http://njbartlett.name/2010/08/05/when-servicetrackers-trump-ds.html
EDIT2: That said: my general policy is to not use an Activator except in super rare cases. Use DS, ipojo, etc and use the components you define with those techs in order get access to the BundleContext to build more low level objects like ServiceTrackers.
hi i am having a different projects in my solution in the initial project (default project) i am accessing the global reference to App.xaml.cs in this way :-
App objref = (App)Application.Current;
But now i have added new project to my solution and trying to access the app.xaml.cs in the same way as defined earlier but i am not able to access app.xaml.cs ?
1)can i know the reason
2)What should i do if i want to use it in both the projects ?
Please let me know
Thanks in advance.
You can access it, but the new project will not be familiar with the derived App class that is in your project. To explain further we need to take inheritance into consideration.
There's a generic definition for the Application class that exposes a number of predefined methods. Your App.xaml.cs is a new class definition that is derived from the Application class. It has the methods it inherited plus what ever methods and properties that you've added. To make use of these any code that is seeking to use your extra properties or methods must have access to the class definition. Your classes in the other projects that you've added do not have access to this definition.
You'll need to make a class or interface definition that both projects have access to. There are several ways of organizing this. I'll present one.
Create your main project in the solution. This contains your
App.xaml.cs.
Create your class library project that contains the
other code.
Create a third project called Common that only contains
an Interface definition.
On the Interface definition define all of the methods/properties
that you want both your class library and main project to have
access too.
Have App.Xaml.cs implement this interface.
In the Class Library access var appReference =
(IMyInterfaceName)Applcation.Current. You'll have access to the
methods that were defined in the interface