Does anyone have any experience with getServiceReference returning null for what seems like no reason?
The following bundle registers the service, and then proceeds to confirm that it's registered (whether or not this is even a valid test from the same package, idk).
package db.connector;
...
public class Activator implements BundleActivator {
private static ServiceRegistration registration;
...
public void start(BundleContext _context) throws Exception {
DatabaseConnector dbc = new DatabaseConnectorImpl();
registration = context.registerService(
DatabaseConnector.class.getName(),
dbc, null);
checkServiceRegistered();
}
...
public void checkServiceRegistered() {
System.out.println("Printing all entries:");
ServiceReference sr = context.getServiceReference(DatabaseConnector.class.getName());
DatabaseConnector dbc = (DatabaseConnector) context.getService(sr);
List<Protocol> result = dbc.getAllProtocols();
for(int i=0; i<result.size(); i++) {
Protocol p = result.get(i);
System.out.println("\t" + p.getId()+": "+p.getName()+"("+p.getOwner()+")");
}
}
}
The output runs successfully, everything seems OK. Checking in the karaf webconsole, the service seems to be registered correctly:
267 [db.connector.DatabaseConnector] database-connector (144)
The code to get the registered service is as follows:
import db.connector.DatabaseConnector;
...
public List<Protocol> printAllEntries() {
ServiceReference sr = Activator.getContext().getServiceReference(DatabaseConnector.class.getName());
DatabaseConnector dbc = (DatabaseConnector) Activator.getContext().getService(sr);
return dbc.getAllProtocols();
}
...
The DatabaseConnector bundle exports the correct package, and the one using the service imports the same.
What could possibly be going wrong here? I'm at a complete loss.
It looks alright.
What comes to mind: Is the ordering ok? Are you sure the registration is done before checking the reference? The way you check in printAllEntries you check if the service is there on just that moment. As OSGi bundles can come and go, this isn't a reliable way to check. You should use either a ServiceTracker, or better still something like Declarative Services or Blueprint.
You could add a ServiceListener to the BundleContext, then you can print out what's happening in what order.
Hope this helps.
Turns out, it was just that I didn't refresh the OSGi bundles. My servlet was pointing to a now-obsolete bundle ID, so of course the service find was failing.
Related
I'm trying to expose a REST service through OSGi (using Apache Felix). I'm using the osgi-jax-rs-connector to publish the resource. Here is the resource interface:
#Path("/bingo")
public interface BingoService {
#GET
#Produces(MediaType.APPLICATION_JSON)
#Path("/lottery")
List<Integer> getLottery();
}
The implementation uses DS annotation to obtain reference to a provided service in container:
#Component(
immediate = true,
service = BingoService.class,
properties = "jersey.properties")
public class Bingo implements BingoService {
#Reference
private RandomNumberGenerator rng;
#Activate
public void activateBingo() {
System.out.println("Bingo Service activated using " +
rng.getClass().getSimpleName());
}
#Override
public List<Integer> getLottery() {
List<Integer> result = new ArrayList<>();
for (int i = 5; i > 0; i--) {
result.add(rng.nextInt());
}
return result;
}
}
jersey.properties simply contains this line
service.exported.interfaces=*
When I deploy the bundle it starts and register the service correctly. But if I go to http://localhost:8181/services/bingo/lottery I get 404.
Could someone point me to the issue or give me some advice on where to look?
On reading the documentation for OSGi - JAX-RS Connector, it expects to find the annotations #Path or #Provider on the service instance object. You have placed them instead on an interface implemented by the component.
I'm not sure what the purpose of the BingoService interface is. This is not required for JAX-RS services. Normally you would register the resource class using its own type (e.g. service=Bingo.class) or simply java.lang.Object.
I have implementated a Rest web service (the function is not relevant) using JAX-RS. Now I want to generate its documentation using Swagger. I have followed these steps:
1) In build.gradle I get all the dependencies I need:
compile 'org.glassfish.jersey.media:jersey-media-moxy:2.13'
2) I documentate my code with Swagger annotations
3) I hook up Swagger in my Application subclass:
public class ApplicationConfig extends ResourceConfig {
/**
* Main constructor
* #param addressBook a provided address book
*/
public ApplicationConfig(final AddressBook addressBook) {
register(AddressBookService.class);
register(MOXyJsonProvider.class);
register(new AbstractBinder() {
#Override
protected void configure() {
bind(addressBook).to(AddressBook.class);
}
});
register(io.swagger.jaxrs.listing.ApiListingResource.class);
register(io.swagger.jaxrs.listing.SwaggerSerializers.class);
BeanConfig beanConfig = new BeanConfig();
beanConfig.setVersion("1.0.2");
beanConfig.setSchemes(new String[]{"http"});
beanConfig.setHost("localhost:8282");
beanConfig.setBasePath("/");
beanConfig.setResourcePackage("rest.addressbook");
beanConfig.setScan(true);
}
}
However, when going to my service in http://localhost:8282/swagger.json, I get this output.
You can check my public repo here.
It's times like this (when there is no real explanation for the problem) that I throw in an ExceptionMapper<Throwable>. Often with server related exceptions, there are no mappers to handle the exception, so it bubbles up to the container and we get a useless 500 status code and maybe some useless message from the server (as you are seeing from Grizzly).
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Response;
import javax.ws.rs.ext.ExceptionMapper;
public class DebugMapper implements ExceptionMapper<Throwable> {
#Override
public Response toResponse(Throwable exception) {
exception.printStackTrace();
if (exception instanceof WebApplicationException) {
return ((WebApplicationException)exception).getResponse();
}
return Response.serverError().entity(exception.getMessage()).build();
}
}
Then just register with the application
public ApplicationConfig(final AddressBook addressBook) {
...
register(DebugMapper.class);
}
When you run the application again and try to hit the endpoint, you will now see a stacktrace with the cause of the exception
java.lang.NullPointerException
at io.swagger.jaxrs.listing.ApiListingResource.getListingJson(ApiListingResource.java:90)
If you look at the source code for ApiListingResource.java:90, you will see
Swagger swagger = (Swagger) context.getAttribute("swagger");
The only thing here that could cause the NPE is the context, which scrolling up will show you it's the ServletContext. Now here's the reason it's null. In order for there to even be a ServletContext, the app needs to be run in a Servlet environment. But look at your set up:
HttpServer server = GrizzlyHttpServerFactory
.createHttpServer(uri, new ApplicationConfig(ab));
This does not create a Servlet container. It only creates an HTTP server. You have the dependency required to create the Servlet container (jersey-container-grizzly2-servlet), but you just need to make use of it. So instead of the previous configuration, you should do
ServletContainer sc = new ServletContainer(new ApplicationConfig(ab));
HttpServer server = GrizzlyWebContainerFactory.create(uri, sc, null, null);
// you will need to catch IOException or add a throws clause
See the API for GrizzlyWebContainerFactory for other configuration options.
Now if you run it and hit the endpoint again, you will see the Swagger JSON. Do note that the response from the endpoint is only the JSON, it is not the documentation interface. For that you need to use the Swagger UI that can interpret the JSON.
Thanks for the MCVE project BTW.
Swagger fixed this issue in 1.5.7. It was Issue 1103, but the fix was rolled in last February. peeskillet's answer will still work, but so will OP's now.
I'm trying to migrate app from jboss 5.1 to 7.1 and i have error like this Error message which i'm not sure why i get this. if anyone have any idea please help me.
Update: 1
#Stateless
#Remote(PackageService.class)
#Interceptors(CrossContextSpringBeanAutowiringInterceptor.class)
#WebContext(contextRoot="/appname_web_services", urlPattern="/MaintenanceService", authMethod="", secureWSDLAccess=false)
#WebService(
name="MaintenanceService",
targetNamespace = "http://appname.com/web/services",
serviceName = "MaintenanceService")
#SOAPBinding(parameterStyle = SOAPBinding.ParameterStyle.WRAPPED)
#HandlerChain(file = "WebServiceHandlerChains.xml")
#TransactionTimeout(10800)
public class MaintenanceServiceBean implements MaintenanceService {
private static final Logger logger = Logger.getLogger( MaintenanceServiceBean.class );
#Resource(mappedName="/ConnectionFactory")
ConnectionFactory connectionFactory;
#Resource(mappedName="topic/manager_system_topic")
javax.jms.Destination systemTopic;
#Autowired
MaintenanceService MigrationService;
#WebMethod
public List<Long> getSoftDeletedPackageIds(Long performedBy) throws Exception {
return MigrationService.getSoftDeletedPackageIds(null);
}
this is the class where i believe it fails.
You are using an interface in your JAXB mappings for which you have not provided enough information to the runtime for it too be able to bind an actual implementation. Without more code included in your question it's hard to recommend a specific solution, but typically you would annotate the included interface with #XmlAnyElement.
You can read through this useful tutorial to determine the best solution for your possible case.
Im trying to use CDI extensions to discover JAX-RS resources at runtime and automatically publish them under different base URIs in a Java SE environment. Applications should not need to extend javax.ws.rs.core.Application themselves if possible.
I have read RestEasy documentation and javadoc but failed to find any obvious way to modify the #ApplicationPath at runtime.
One idea that im exploring is to try generate javax.ws.rs.core.Application and set the #ApplicationPath base URI programmatically, maybe by using an AnnotatedType CDI extension, and publish that as a * org.jboss.resteasy.spi.ResteasyDeployment`.
Are there other/better ways to do this?
EDIT:
Trying CDI extension event ProcessAnnotatedType to change #javax.ws.rs.Path of JAX-RS resources.
<X> void process(#Observes ProcessAnnotatedType<X> pat) {
if (!pat.getAnnotatedType().isAnnotationPresent(javax.ws.rs.Path.class)) {
return;
}
final AnnotatedType<X> org = pat.getAnnotatedType();
AnnotatedType<X> wrapped = new AnnotatedType<X>() {
#Override
public <T extends Annotation> T getAnnotation(final Class<T> annotation) {
if (javax.ws.rs.Path.class.equals(annotation)) {
class PathLiteral extends AnnotationLiteral<javax.ws.rs.Path> implements javax.ws.rs.Path {
#Override
public String value() {
return "change_me/" + (javax.ws.rs.Path) org.getAnnotation(annotation);
}
}
return (T) new PathLiteral();
} else {
return org.getAnnotation(annotation);
}
}
pat.setAnnotatedType(wrapped);
}
... then after bootstrap, constructing the bean using javax.enterprise.inject.spi.BeanManager was expecting the following code to print "change_me/...."
Set<Bean<?>> beans = beanManager.getBeans(jaxrsClass);
for (Bean<?> bean : beans) {
CreationalContext cc = bm.createCreationalContext(bean);
Object jaxrs = bean.create(cc);
Path p = jaxrs.getClass().getAnnotation(Path.class);
System.out.println(p.value());
}
... but this does not work. javax.ws.rs.Path is unchanged for JAX-RS resource 'jaxrsClass'.
What is wrong?
I doubt this can be done in a reliable way. It probably all comes down to which happens first: the CDI bootstrap or JAX-RS, of course in the future or in other application servers it could all be done in parallel.
It's certainly a cool idea though. What have they said on the RestEasy forums?
We are already using such an approach.
We are using the feature to use Subresource locators and take the power of guice.
At the startup we are scanning the classpath for all resources annotated with #Path. After that we are extracting the path and binding the resources with the help of Names/#Named. So the resources can later be injected with the help of the name.
bind(..).annotatedWith(Names.named("path")).to(..)
The next step is that you need a resource with a subresource locator.
#Path("{name}")
public Object find(#PathParam("name") name){
return injector.getInstance(..);
}
You could use this approach to bind them at runtime and also to change the original annotated path.
Thanks in advance for your assistance. I have the following exported part:
[Export (typeof(INewComponent))] // orignally tried just [Export} here and importing NewComponent below
public class NewComponent : INewComponent
{
// does stuff including an import
}
The Console test program imports the above:
public class Program
{
[Import] // have tried variations on importing "NewComponent NewComponent" etc
public INewComponent NewComponent
{
get;
set;
}
public static void Main(string[] args)
{
var p = new Program();
var catalog = new AssemblyCatalog(typeof(Program).Assembly);
var container = new CompositionContainer(catalog);
container.ComposeParts(p);
}
The Composition fails with these CompositionExceptions (I removed the namespace to protect the guilty :)):
1) No valid exports were found that match the constraint
'((exportDefinition.ContractName == "INewComponent") AndAlso
(exportDefinition.Metadata.ContainsKey("ExportTypeIdentity") AndAlso
"INewComponent".Equals(exportDefinition.Metadata.get_Item("ExportTypeIdentity"))))',
invalid exports may have been rejected.
The Composition works successfully if I do the composition in the main program like this:
public class Program
{
public static void Main(string[] args)
{
INewComponent newComponent = new NewComponent();
var catalog = new AssemblyCatalog(typeof(Program).Assembly);
var container = new CompositionContainer(catalog);
container.ComposeParts(newComponent);
}
}
Thank You
Is your Exported part contained in the same Assembly as Program? If it is in a separate DLL, you need to include that Assembly in your catalog as well, like this:
var aggregateCatalog = new AggregateCatalog();
aggregateCatalog.Catalogs.Add(new AssemblyCatalog(typeof(Program).Assembly));
aggregateCatalog.Catalogs.Add(new AssemblyCatalog(typeof(NewComponent).Assembly));
var container = new CompositionContainer(aggregateCatalog);
// etc...
If that's doesn't work, then there is a nice open source tool called Visual MEFx that can help you analyze your catalog. Here is a short article about setting it up:
Getting Started With Visual MEFx
In your NewComponent class you wrote this:
// does stuff including an import
If there is a problem with that unshown import, then MEF will complain about the Program.NewComponent import instead of the actual deeper cause. This is called "stable composition". Stable composition can be useful, but it also complicates the debugging of a failed composition.
You can follow the instructions in the MEF documentation about Diagnosing Composition Errors to home in on the actual cause.
In a small program, you can also try to call container.GetExportedValue<ISomeExport>() for a few exports until you find the one that is causing problems.