We are facing a problem with Hystrix Command in a Spring Boot / Cloud microservice. We have a Spring Component containing a method annotated with #RabbitListener. When a new message arrives, the method delegates the invocation to NotificationService::processNotification().
The NotificationService is a bean annotated with #Service. The method processNotification() can request third party applications. We want to wrap the invocation of third party applications using #HystrixCommand to provide fault tolerance, but due to some reasons the Hystrix Command annotated method is not working.
If we invoke a Controller and the Controller delegates the invocation to a Service method, which in turns have a Hystrix Command , everything works perfectly. The only problem with Hystrix Command arises when the microservices consume a messages and it seems to be Hystrix Command doesn’t trigger the fallback method.
Here is the non-working code:
#Component
public class MessageProcessor {
#Autowired
private NotificationService notificationService;
#RabbitListener(queues = "abc.xyz-queue")
public void onNewNotification(String payload) {
this.notificationService.processNotification(payload);
}
}
#Service
public class NotificationService {
public void processNotification(String payload) {
...
this.notifyThirdPartyApp(notificationDTO);
...
}
#HystrixCommand(fallbackMethod = "notifyThirdPartyAppFallback")
public void notifyThirdPartyApp(NotificationDTO notificationDTO) {
//Do stuff here that could fail
}
public void notifyThirdPartyAppFallback(NotificationDTO notificationDTO) {
// Fallbacl impl goes here
}
}
#SpringBootApplication
#EnableCaching
#EnableCircuitBreaker
#EnableDiscoveryClient
#EnableRabbit
public class NotificationApplication {
public static void main(String[] args) {
SpringApplication.run(NotificationApplication.class, args);
}
}
I'm not sure about your problem without looking at the code.
As another approach you can take: instead of describing this calls with annotations in your service, just extend HystrixCommand and implement api calling logic in it (read more):
public class CommandHelloWorld extends HystrixCommand<String> {
private final String name;
public CommandHelloWorld(String name) {
super(HystrixCommandGroupKey.Factory.asKey("ExampleGroup"));
this.name = name;
}
#Override
protected String run() {
// a real example would do work like a network call here
return "Hello " + name + "!";
}
}
Related
I have inherited a springboot application. This application has a service similar to the following:
#Service
public class MyService {
String param1 = "";
String param2 = "";
public void doStuff() {
// do stuff assuming the parameters param1 and param 2 of this autowired service have already been initialized
}
}
, This service is autowired from another service similar to the following;
#Service
public MainService {
#Autowired MyService myService;
public performWork() {
this.myService.doStuff();
}
}
, and finally, the springboot app is similar to the following. The calling of the listen() method happens once the Kafka topic has a message (Kafka is only here relevant here because it kicks off the calling of the autowired services):
#SpringBootApplication
public class MyApplication {
#Autowired
MainService mainService;
public static void main(String[] args) {
SpringApplication.run(MyApplication.class, args);
}
#KafkaListener(topics = "myTopic")
public void listen(String message) {
this.graphicService.performWork();
}
}
Here is my question: What is a proper way to have the parameters param1 and param2 already initialized on the MyService service before its doStuff() method is called?
I would instead NOT use a bean configuration file, but rather have it performed as part of the starting of the springboot app. Any advice is appreciated. Thanks
Per my understanding, you just want to execute initialization statements at your bean's initialization. You can use PostConstruct annotation for any work you need to do as soon as beans are created.
MyService class should look like the following
#Service
public class MyService {
String param1;
String param2;
#PostConstruct
public void postConstructRoutine() {
// initialize parameters
param1 = "some_value";
param2 = "some_other_value";
}
public void doStuff() {
// do stuff
}
}
The PostConstruct annotation is used on a method that needs to be executed after dependency injection is done to perform any initialization.
You can find more info about the annotation at the documentation.
As a side note, it is always better to use constructor injection instead of Autowired. I would highly recommend it.
I have a customized spring-boot-starter which will call some REST APIs when it gets a spring application event of ApplicationReadyEvent, so the configuration class is something like:
#Configuration
public class MySpringBootStarter {
#EventListener(ApplicationReadyEvent.class)
public void init() {
// Call REST APIs here
}
}
Then, I want to test the starter using MockServer which requires creating some expectations before the test runs. The test class may look like as follows:
#ExtendWith(MockServerExtension.class)
#SpringBootTest
#ContextConfiguration
#MockServerSettings(ports = {28787, 28888})
public class MySpringBootStarterTest {
private MockServerClient client;
#BeforeEach
public void beforeEachLifecycleMethod(MockServerClient client) {
this.client = client;
//creating expectations here
}
#Test
void shouldBeTrue() {
assertThat(true).isTrue();
}
#SpringBootApplication
static class MyTest {
public void main(String[] args) {
SpringApplication.run(Test.class, args);
}
}
}
But in fact, the expectations are always created after the ApplicationReadyEvent, viz., the init method of MySpringBootStarter class is called before the the beforeEachLifecycleMethod method in MySpringBootStarterTest class.
How can I make the test work, please?
You can use static block initializer to run required code before SpringContext boots up.
I have a resource endpoint that injects a #PathParam into constructor, i.e., different instance per #PathParam value. It all works fine in Jetty. But now I'm trying to write unit tests using Jersey Test Framework, and it seems that the test framework only supports one registered endpoint per type.
So if I do something like this:
#Path("/users")
public class MyResource {
public MyResource(#PathParam("userId") int userId) {
}
#Path("{userId}")
public String get() {
}
}
public class MyTest extends JerseyTestNg.ContainerPerClassTest {
#Override
protected Application configure() {
return new ResourceConfig()
.register(new MyResource(1))
.register(new MyResource(2));
}
#Test
public void test2() {
target("/users/1").request().get();
}
#Test
public void test2() {
target("/users/2").request().get();
}
}
I see that both test1 and test2 are invoking the instance of MyResource(1). Is this expected? Is there a solution to invoke the correct instance?
You should register the resource as a class. Jersey will create it for you. And handle all the injections.
"The example I posted is dumbed down. In reality, my resource constructor has another injected object that I need to mock. So how would I specify a mocked object parameter for the constructor?"
You can do something like
#Mock
private Service service;
#Override
public ResourceConfig configure() {
MockitoAnnotations.initMocks(this);
return new ResourceConfig()
.register(MyResource.class)
.register(new AbstractBinder() {
#Override
protected configure() {
bind(service).to(Service.class);
}
});
}
#Test
public void test() {
when(service.getSomething()).thenReturn("Something");
// test
}
Assuming you are already using the built in HK2 DI, and have an #Inject annotation on the constructor of your resource class, this should work. In the AbstractBinder we are making the mock object injectable. So now Jersey can inject it into your resource.
See Also:
Jersey - How to mock service
I have the following route configuration:
#Component
public class MyRoute extends RouteBuilder {
#Override
public void configure() throws Exception {
from("direct:in").to("direct:out");
}
}
When I try to test it:
#RunWith(CamelSpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = { MyRouteTest.TestConfig.class }, loader = CamelSpringDelegatingTestContextLoader.class)
#MockEndpoints
public class MyRouteTest {
#EndpointInject(uri = "mock:direct:out")
private MockEndpoint mockEndpoint;
#Produce(uri = "direct:in")
private ProducerTemplate producerTemplate;
#Configuration
public static class TestConfig extends SingleRouteCamelConfiguration {
#Bean
#Override
public RouteBuilder route() {
return new MyRoute();
}
}
#Test
public void testRoute() throws Exception {
mockEndpoint.expectedBodiesReceived("Test Message");
producerTemplate.sendBody("Test Message");
mockEndpoint.assertIsSatisfied();
}
}
I get this exception:
org.apache.camel.component.direct.DirectConsumerNotAvailableException:
No consumers available on endpoint: Endpoint[direct://out].
Exchange[Message: Test Message]
It looks like the Mock is not picking up the message from the endpoint.
What am I doing wrong?
The problem is that mock endpoints just intercept the message before delegating to the actual endpoint. Quoted from the docs:
Important: The endpoints are still in action. What happens differently
is that a Mock endpoint is injected and receives the message first and
then delegates the message to the target endpoint. You can view this
as a kind of intercept and delegate or endpoint listener.
The solution to your problem is to tell certain endpoints (the ones that expect a consumer in your case) not to delegate to the actual endpoint. This can easily be done using #MockEndpointsAndSkip instead of #MockEndpoints:
#RunWith(CamelSpringJUnit4ClassRunner.class)
#ContextConfiguration(classes = { MyRouteTest.TestConfig.class }, loader = CamelSpringDelegatingTestContextLoader.class)
#MockEndpointsAndSkip("direct:out") // <-- turns unit test from red to green ;)
public class MyRouteTest {
// ....
}
This issue because, in your route configuration, there is no route with "direct:out" consumer endpoint.
add a line like some thing below,
from("direct:out").("Anything you want to log");
So that direct:out will consume the exchange and In your test, mock will be able check the received text without any issues. Hope this helps !!
I am using this Spring AOP code in my Spring Boot starter project in STS. After debugging this for some time I don't see any problem with the AspectJ syntax. The Maven dependencies are generated by STS for a AOP starter project. Is there a glaring omission in this code like an annotation ? The other problem could be with the AOP starter project or with the way I try to test the code in a #PostConstruct method.
I installed AJDT but it appears STS should show AspectJ markers in the IDE on its own. Right ? I don't see the markers. What other AspectJ debugging options are included in STS ? -Xlint is what I used in Eclipse/AJDT.
StateHandler.java
public class StateHandler<EVENTTYPE extends EventType> {
private State<EVENTTYPE> state;
private Event<EVENTTYPE> event;
public StateHandler(State<EVENTTYPE> state, Event<EVENTTYPE> event) {
this.state = state;
this.event = event;
}
public void handle( Event<EVENTTYPE> event ){
state = state.handle( event );
}
public State<EVENTTYPE> getState() {
return state;
}
}
DeviceLogger .java
#Aspect
#Component
public class DeviceLogger {
private static Logger logger = Logger.getLogger("Device");
#Around("execution(* com.devicemachine.StateHandler.*(..))")
public void log() {
logger.info( "Logger" );
}
}
LoggerApplication.java
#SpringBootApplication
public class LoggerApplication {
private static Logger logger = Logger.getLogger("Device");
public static void main(String[] args) {
SpringApplication.run(LoggerApplication.class, args);
}
#PostConstruct
public void log(){
DeviceState s = DeviceState.BLOCKED;
StateHandler<DeviceEvent> sh = new StateHandler<DeviceEvent>( s,
Event.block(DeviceEvent.BLOCKED, "AuditMessage") );
sh.handle(Event.block(DeviceEvent.UNBLOCKED, "AuditMessage"));
}
}
There are 3 obvious things wrong and 1 not so obvious wrong.
Your aspect is wrong and breaks proper method execution. When using an around aspect you must always return Object and use a ProceedingJoinPoint and call proceed() on that.
You are creating new instances of classes yourself, Spring, by default, uses proxy based AOP and will only proxy beans it knows.
In a #PostConstruct method it might be that proxies aren't created yet and that nothing is being intercepted
You need to use class based proxies for that to be enabled add spring.aop.proxy-target-class=true to your application.properties. By default JDK Dynamic Proxies are used which are interface based.
Fix Aspect
Your current aspect doesn't use a ProceedingJoinPoint and as such never does the actual method call. Next to that if you now would have a method that returns a value it would all of a sudden return null. As you aren't calling proceed on the ProceedingJoinPoint.
#Around("execution(* com.devicemachine.StateHandler.*(..))")
public Object log(ProceedingJoinPoint pjp) throws Throwable {
logger.info( "Logger" );
return pjp.proceed();
}
Create a bean to fix proxying and #PostConstruct
#SpringBootApplication
public class LoggerApplication {
private static Logger logger = Logger.getLogger("Device");
public static void main(String[] args) {
ApplicationContext context = SpringApplication.run(LoggerApplication.class, args);
StateHandler<DeviceEvent> sh = context.getBean(StateHandler<DeviceEvent>.class);
sh.handle(Event.block(DeviceEvent.UNBLOCKED, "AuditMessage"));
}
#Bean
public StateHandler<DeviceEvent> auditMessageStateHandler() {
return new StateHandler<DeviceEvent>(DeviceState.BLOCKED, Event.block(DeviceEvent.BLOCKED, "AuditMessage") );
}
}
Add property to enable class proxies
In your application.properties in src\main\resources add the following property with a value of true
spring.aop.proxy-target-class=true