Combine Jersey with Tyrus - websocket

I have a Jersey JAX-RS application which runs on a Grizzly instance:
public class Application {
public static final String BASE_URI = "http://127.0.0.1:8080/rest";
public static void main(String[] args) throws IOException {
ResourceConfig rc = new ResourceConfig().packages("my.package.rest");
HttpServer server = GrizzlyHttpServerFactory.createHttpServer(URI.create(BASE_URI), rc);
System.out.println("Server started, press any key to stop.");
System.in.read();
server.shutdownNow();
}
}
inside my.package.rest there are JAX-RS annotated resources. I'd like to add websocket annotated (#ServerEndpoint, #OnOpen, #OnMessage, etc.) resources using Tyrus on the same server instance (say in "http://127.0.0.1:8080/websocket") but all the documentation I was able to find shows how to start a standalone websocket server using Tyrus + a Grizzly container, not combined with Jersey. I'm looking for something like:
server.getServerConfiguration().addHttpHandler(new SomeTyrusHttpHandler("/websocket"));
but I can't find anything similar to SomeTyrusHttpHandler. How can I combine Jersey and Tyrus in a single Grizzly server?

good question, but there is currently no good answer for this one. You still can do that, but it would require to deep dive into Grizzly internals; Tyrus is registered by an addon (see WebSocketAddOn) and it can be combined with Jersey way of registering into that container.
Please have in mind that integrating these two frameworks together is not trivial challenge - running them in a single container is a first step, but there are other things which need to be taken care of, like "instance provider", lifecycle adjustment, etc. I believe this topic exceeds the scope of one SO answer - you can expect blogpost from me or some other Tyrus/Jersey team member about this. (I'll post it here once that is done).
Anyway, I would recommend to take more conservative approach and use some lightweight container which supports Servlet 3.1; that should require far less work on your side and you'll have standard Servlet runtime / lifecycle.

Related

Configuration Bean in Quarkus

This is regarding CDI spec of quarkus. Would want to understand is there a configuration bean for quarkus? How does one do any sort of configuration in quarkus?
If I get it right the original question is about #Configuration classes that can contain #Bean definitions. If so then CDI producer methods and fields annotated with #javax.enterprise.inject.Produces are the corresponding alternative.
Application configuration is a completely different question though and Jay is right that the Quarkus configuration reference is the ultimate source of information ;-).
First of all reading how cdi spec of quarkus differs from spring is important.
Please refer this guide:
https://quarkus.io/guides/cdi-reference
The learnings from this guide is there is #Produces which is an alternative to #Configuration bean in Quarkus.
Let us take an example for libs that might require a configuration through code. Example: Microsoft Azure IOT Service Client.
public class IotHubConfiguration {
#ConfigProperty(name="iothub.device.connection.string")
String connectionString;
private static final Logger LOG = Logger.getLogger(IotHubConfiguration.class);
#Produces
public ServiceClient getIot() throws URISyntaxException, IOException {
LOG.info("Inside Service Client bean");
if(connectionString==null) {
LOG.info("Connection String is null");
throw new RuntimeException("IOT CONNECTION STRING IS NULL");
}
ServiceClient serviceClient = new ServiceClient(connectionString, IotHubServiceClientProtocol.AMQPS);
serviceClient.open();
LOG.info("opened Service Client Successfully");
return serviceClient;
}
For all libs vertically intergrated with quarkus application.properties can be used and then you will get a driver obj for that broker/dbs available directly through #Inject in your #applicationScoped/#Singleton bean So, Why is that?
To Simplify and Unify Configuration
To Make Sure no code is required for configuring anything i.e. database config, broker config , quarkus config etc.
This drastically reduces the amount of code written for configuring and also Junits needed to cover that code.
Let us take an example where kafka producer configuration needs to be added: in application.properties
kafka.bootstrap.servers=${KAFKA_BROKER_URL:localhost:9092}
mp.messaging.outgoing.incoming_kafka_topic_test.topic=${KAFKA_INPUT_TOPIC_FOR_IOT_HUB:input_topic1}
mp.messaging.outgoing.incoming_kafka_topic_test.connector=smallrye-kafka
mp.messaging.outgoing.incoming_kafka_topic_test.value.deserializer=org.apache.kafka.common.serialization.StringDeserializer
mp.messaging.outgoing.incoming_kafka_topic_test.key.deserializer=org.apache.kafka.common.serialization.StringDeserializer
mp.messaging.outgoing.incoming_kafka_topic_test.health-readiness-enabled=true
For full blown project reference: https://github.com/JayGhiya/QuarkusExperiments/tree/initial_version_v1/KafkaProducerQuarkus
Quarkus References for Config:
https://quarkus.io/guides/config-reference
Example for reactive sql config: https://quarkus.io/guides/reactive-sql-clients
Now let us talk about a bonus feature that quarkus provides which improves developer experience by atleast an order of magnitude that is profile driven development and testing.
Quarkus provides three profiles:
dev - Activated when in development mode (i.e. quarkus:dev)
test - Activated when running tests
prod - The default profile when not running in development or test
mode
Let us just say that in the given example you wanted to have different topics for development and different topics for production. Let us achieve that!
%dev.mp.messaging.outgoing.incoming_kafka_topic_test.topic=${KAFKA_INPUT_TOPIC_FOR_IOT_HUB:input_topic1}
%prod.mp.messaging.outgoing.incoming_kafka_topic_test.topic=${KAFKA_INPUT_TOPIC_FOR_IOT_HUB:prod_topic}
This is how simple it is. This is extremely useful in cases where your deployments run with ssl enabled brokers/dbs etc and for dev purposes you have unsecure local brokers/dbs. This is a game changer.

Spring with Apache Beam

I want to use Spring with Apache Beam that will run on Google Cloud Data flow Runner. Dataflow job should be able to use Spring Runtime application context while executing the Pipeline steps. I want to use Spring feature in my Apache Beam pipeline for DI and other stuff. After browsing hours on google, I couldn't find any post or documentation which shows Spring integration in Apache Beam. So, if anyone has tried spring with Apache beam, please let me know.
In main class i have initialised the spring application context but it is not available while execution of pipeline steps. I get null pointer exception for autowired beans. I guess the problem is, at runtime context is not available to worker threads.
public static void main(String[] args) {
initSpringApplicationContext();
GcmOptions options = PipelineOptionsFactory.fromArgs(args)
.withValidation()
.as(GcmOptions.class);
Pipeline pipeline = Pipeline.create(options);
// pipeline definition
}
I want to inject the spring application context to each of the ParDo functions.
The problem here is that the ApplicationContext is not available on any worker, as the main method is only called when constructing the job and not on any worker machine. Therefore, initSpringApplicationContext is never called on any worker.
I've never tried to use Spring within Apache Beam, but I guess moving initSpringApplicationContext in a static initializer block will lead to your expected result.
public class ApplicationContextHolder {
private static final ApplicationContext CTX;
static {
CTX = initApplicationContext();
}
public static ApplicationContext getContext() {
return CTX;
}
}
Please be aware that this alone shouldn't be considered as a best practice of using Spring within Apache Beam since it doesn't integrate well in the lifecycle of Apache Beam. For example, when an error happens during the initialization of the application context, it will appear in the first place where the ApplicationContextHolder is used. Therefore, I'd recommend to extract initApplicationContext out of the static initializer block and call it explicitly with regards to Apache Beam's Lifecycle. The setup phase would be a good place for this.

JAX-RS: How to run a method on start (without servlets)

I have a JAX-RS (Jersey) server with which I register and bind my stuff.
I want to print a banner when the server starts up. I want to do this using the JAX-RS framework not the web server's platform (i.e., no Jetty, Netty, Thorntail, etc hooks).
I saw the following which mentions the tried and true Servlet way of doing things:
Jax rs: How can I run a method automatically everytime my server restarts? , but that does not work because I am not running a servlet container in my server so that lifecycle call is never made.
I figured there must be a JCA-ish type object that I can register with Application/ResourceConfig that has such a lifecycle call, but I am unable to even find any kind of list of the things you can actually register.
Not to complain (but I will), but I cannot decide if this is so difficult because when they moved the project to eclipse, they broke every hyperlink to the old official documentation or that it is simply so implicit, like Spring, that it only works by github'ing other people's code and realizing, 'oh, I did not know you could do that'.
Jersey has Event Listeners. You'll want to use the ApplicationEventListener and the ApplicationEvent.Type you'll probably want to listen for to print the banner is the INITIALIZATION_FINISHED
public class MyApplicationEventListener
implements ApplicationEventListener {
#Override
public void onEvent(ApplicationEvent event) {
switch (event.getType()) {
case INITIALIZATION_FINISHED:
printBanner();
break;
}
}
#Override
public RequestEventListener onRequest(RequestEvent requestEvent) {
return null;
}
}

Spring Integration: Automated integration tests with embedded Broker?

Is it in a way possible to, say in memory, start a broker that can be used to execute automated test cases using Spring Integration MQTT?
I've tried achieving this with ActiveMQ (following https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-messaging.html) but somehow didn't succeed, maybe anyone has a short working example?
It's not Spring Integration (Spring Boot) responsibility to provide some embedded broker for such a protocol. If there is one, we could consider to implement an auto-configuration on the matter , similar to what we do for embedded RDBMS, JMS and MongoDB. You really need to consult ActiveMQ documentation.
Looks like we can do it like this in the test class:
private static BrokerService activeMQBroker;
...
#BeforeClass
public static void setup() throws Exception {
activeMQBroker = new BrokerService();
activeMQBroker.addConnector("mqtt://localhost:1883");
activeMQBroker.setPersistent(false);
activeMQBroker.setUseJmx(false);
activeMQBroker.start();
}
I didn't try it, but this is exactly what I do to test against STOMP.

Unit testing with Spring and the Jersey Test Framework

I'm writing some JUnit-based integration tests for a RESTful web service using JerseyTest. The JAX-RS resource classes use Spring and I'm currently wiring everything together with a test case like the following code example:
public class HelloResourceTest extends JerseyTest
{
#Override
protected AppDescriptor configure()
{
return new WebAppDescriptor.Builder("com.helloworld")
.contextParam( "contextConfigLocation", "classpath:helloContext.xml")
.servletClass(SpringServlet.class)
.contextListenerClass(ContextLoaderListener.class)
.requestListenerClass(RequestContextListener.class)
.build();
}
#Test
public void test()
{
// test goes here
}
}
This works for wiring the servlet, however, I'd like to be able to share the same context in my test case so that my tests can have access to mock objects, DAOs, etc., which seems to call for SpringJUnit4ClassRunner. Unfortunately, SpringJUnit4ClassRunner creates a separate, parallel application context.
So, anyone know how can I create an application context that is shared between the SpringServlet and my test case?
Thanks!
Override JerseyTest.configure like so:
#Override
protected Application configure() {
ResourceConfig rc = new JerseyConfig();
rc.register(SpringLifecycleListener.class);
rc.register(RequestContextFilter.class);
rc.property("contextConfigLocation", "classpath:helloContext.xml");
return rc;
}
For me the SpringServlet was not required, but if you need that you may be able to call rc.register for that too.
I found a couple of ways to resolve this problem.
First up, over at the geek#riffpie blog there is an excellent description of this problem along with an elegant extension of JerseyTest to solve it:
Unit-testing RESTful Jersey services glued together with Spring
Unfortunately, I'm using a newer version of Spring and/or Jersey (forget which) and couldn't quite get it to work.
In my case, I ended up avoiding the problem by dropping the Jersey Test Framework and using embedded Jetty along with the Jersey Client. This actually made better sense in my situation anyway since I was already using embedded Jetty in my application. yves amsellem has a nice example of unit testing with the Jersey Client and embedded Jetty. For Spring integration, I used a variation of Trimbo's Jersey Tests with Embedded Jetty and Spring

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