I have a JMS listener which is receiving ByteMessage from another application. The current application is working with Spring JMS. I am trying to introduce spring integration here. So I added the following sample code to listen for the message.
#Configuration
public class JmsConfiguration {
#Bean
public IntegrationFlow integrationFlow(ConnectionFactory connectionFactory) {
return IntegrationFlows
.from(Jms.messageDrivenChannelAdapter(connectionFactory)
.destination("fooQueue"))
.transform("hello "::concat)
.get();
}
Then I am getting the class cast exception as below:
java.lang.ClassCastException: [B cannot be cast to java.lang.String
I am getting a ByteMessage and I am not finding a good example on how the ByteMessage with Byte array payload can be extracted. I am new to the spring integration world.
Add .transform(Transformers.objectToString()) before your .transform(). BytesMessage will result in a message with a byte[] payload so you need to convert it to a String before trying to concatenate it.
Related
I have multiple feign clients in a Spring Boot application. I am using a Controller Advice for handling custom exceptions for each feign client.
Here my controller advice that handles two custom exceptions (one for each client: client1 and client2):
#ControllerAdvice
public class ExceptionTranslator implements ProblemHandling {
#ExceptionHandler
public ResponseEntity<Problem> handleCustomClient1Exception(CustomException1 ex, NativeWebRequest request) {
Problem problem = Problem.builder()
.title(ex.getTitle())
.detail(ex.getMessage())
.status(ex.getStatusType())
.code(ex.getCode())
.build();
return create(ex, problem, request);
}
#ExceptionHandler
public ResponseEntity<Problem> handleCustomClient2Exception(CustomException2 ex, NativeWebRequest request) {
Problem problem = Problem.builder()
.title(ex.getTitle())
.detail(ex.getMessage())
.status(ex.getStatusType())
.code(ex.getCode())
.build();
return create(ex, problem, request);
}
}
I have implemented an error decoder for feign client1.
public class ClientErrorDecoder implements ErrorDecoder {
final ObjectMapper mapper;
public ClientErrorDecoder() {
this.mapper = new ObjectMapper();
}
#Override
public Exception decode(String methodKey, Response response) {
ExceptionDTO exceptionDTO;
try {
exceptionDTO = mapper.readValue(response.body().asInputStream(), ExceptionDTO.class);
} catch (IOException e) {
throw new RuntimeException("Failed to process response body.", e);
}
return new CustomException1(exceptionDTO.getDetail(), exceptionDTO.getCode(), exceptionDTO.getTitle(), exceptionDTO.getStatus());
}
}
I have also configured feign for using that error decoder for that specific client like this:
feign:
client:
config:
client1:
errorDecoder: feign.codec.ErrorDecoder.Default
My question is: what is the best approach for handling more than one feign client exceptions? Should I use the same error decoder and treat their responses as a generic exception? Or should I create an error decoder for each feign client?
Quick Answer
If you work with different APIs, error responses will not be formatted the same way. Hence handling them separately seems to be the best approach.
Remarks
From your example, it seems like you defined a custom ErrorDecoder that may
be not used because you also configured feign to use default error decoder for you client1 in properties file.
Even if you defined a #Configuration class somewhere with a bean for your custom ClientErrorDecoder,
Spring Cloud documentation mentions that configuration properties take precedence over #Configuration annotation
If we create both #Configuration bean and configuration properties,
configuration properties will win. It will override #Configuration
values. But if you want to change the priority to #Configuration, you
can change feign.client.default-to-properties to false.
Example
Here is a hypothetical pruned configuration to handle multiple feign clients with different error decoders :
Client1:
You tell feign to load beans defined in CustomFeignConfiguration class for client1
#FeignClient(name = "client1", configuration = {CustomFeignConfiguration.class})
public interface Client1 {...}
Client2:
Client2 will use default Feign ErrorDecoder because no configuration is specified. (Will throw a FeignException on error)
#FeignClient(name = "client2")
public interface Client2 {...}
Configuration: Be carefull here, if you add #Configuration to CustomFeignConfiguration, then ClientErrorDecoder bean will be used for every loaded feign clients (depending on your application component scanning behaviour)
public class CustomFeignConfiguration {
#Bean
public ClientErrorDecoder clientErrorDecoder(ObjectMapper objectMapper) {
return new ClientErrorDecoder(objectMapper);
}
}
This configuration could be done with properties file aswell.
Side remark
From my point of view, you don't even need controller advice. If you use Spring Web #ResponseStatus annotation, you can tell which HTTP status code should be sent back with exception body thrown by your custom ErrorDecoder.
Helpeful resources
Spring Cloud Documentation
GitHub issue related to the subject
I've created a Gateway and a polling notificationChannel which the Gateway uses to route messages. I want a service activator to poll from the channel and do its thing. But I can't seem to grasp a few things about Spring Integration.
In this case would we need an IntegrationFlow Bean? Wouldn't calling the gateway method just send the message trough the channel and the service activator can just poll automatically when there is a new message?
ConfigurationClass:
#EnableIntegration
#Configuration
#IntegrationComponentScan
class IntegrationConfiguration {
#Bean
fun notificationChannel(): MessageChannel {
return MessageChannels.queue().get()
}
#Bean
fun integrationFlow(): IntegrationFlow {
TODO()
}
}
Gateway:
#MessagingGateway(defaultRequestChannel = "notificationChannel")
#Component
interface NotificationGateway {
fun sendNotification(bytes: ByteArray)
}
Service:
#Service
class NotificationService {
#ServiceActivator(inputChannel = "notificationChannel")
fun sendNotification(bytes: ByteArray) {
TODO()
}
}
I am new to Spring Integration and having a rough time since I can't find understandable documentation for my level of knowledge especially on Spring Integration DSL.
My main problem might be that I do now understand the use of the IntegrationFlow Bean
For a simple use-case like yours you indeed don't need an IntegrationFlow. The simple #ServiceActivator as you have now is fully enough to process messages from the notificationChannel. Only what you need is a #Poller in that #ServiceActivator configuration since your notificationChannel is a PollableChannel one and it is not subscribable one.
See Reference Manual for more info: https://docs.spring.io/spring-integration/docs/current/reference/html/#configuration-using-poller-annotation
Also pay attention to the paragraph in the beginning of the doc: https://docs.spring.io/spring-integration/docs/current/reference/html/#programming-considerations
I'm trying to use Spring Cloud Stream to publish and consume Kafka messages. I've been working off of the documentation here on Accessing Bound Channels. I'm trying to use a custom name on the channel for my topic, so I have a #Qualifier when I'm trying to inject it, but spring can't find the relevant bean. It says "For each bound interface, Spring Cloud Stream will generate a bean that implements the interface", but the auto-wiring isn't working.
The error I'm getting is "Parameter 0 of constructor in com...MessagingManager required a bean of type 'org.springframework.messaging.MessageChannel' that could not be found."
I tried using #Autowired before the MessagingManager constructor like in the example, but then got a similar error in bean factory about there being 2 of them, so I took it out, and got the current error.
It's probably complicated by my trying to use a Processor.
Here are my components. I'm running it with spring boot and trying to test it with this :
#Component
public class StartupTester implements ApplicationListener<ContextRefreshedEvent> {
MessagingManager messagingManager;
#Override
public void onApplicationEvent(ContextRefreshedEvent event) {
messagingManager.sendThingCreatedMessage(new ThingCreated("12345", "667788"));
}
}
#Component
public class MessagingManager {
private MessageChannel thingCreatedChannel;
public MessagingManager(#Qualifier(ThingChannelProcessor.THING_CREATED) MessageChannel output) {
thingCreatedChannel = output;
}
public void sendThingCreatedMessage(ThingCreated thingCreated) {
thingCreatedChannel.send(MessageBuilder.withPayload(thingCreated).build());
}
}
#Component
public interface ThingsChannelProcessor extends Processor {
String THING_REQUEST = "thing-request";
String THING_CREATED = "thing-created";
#Input(THING_REQUEST )
SubscribableChannel thingsRequest();
#Output(THING_CREATED )
MessageChannel thingCreated();
}
And I also have #EnableBinding(ThingsMessagingManager.class) on my main class which is annotated with #SpringBootApplication.
I could not reproduce your error. But I have a few points you could follow:
You don't need to annotate the interface with #Component
It seems that you have a typo on your #EnableBinding you should have #EnableBinding(ThingsChannelProcessor.class) not ThingsMessagingManager
You don't need to extend Processor either, that may be the reason why you got 2 beans in the first time. If you are customizing your channels, you don't need to descend from Sink/Source/Processor, look at the Barista example in the docs
Listen for an contextRefresh won't work either, as we do the binding after the context was refreshed
Actually, let me a bit more clear on 4. We create a child context, so in order to make sure that your context has fully initialized, make sure you also implement ApplicationContextAware on your Starter, and before sending the message check if the contexts are the same otherwise you will get an error if(this.context.equals(event.getApplicationContext()))
I have successfully integrated kafka outbound channle adapter with fixed topic name. Now, i want to make the topic name configurable and hence, want to expose it via application properties.
application.properties contain one of the following entry:
kafkaTopic:testNewTopic
My configuration class looks like below:
#Configuration
#Component
public class KafkaConfig {
#Value("${kafkaTopic}")
private String kafkaTopicName;
#Bean
public String getTopic(){
return kafkaTopicName;
}
#Bean
public KafkaTemplate<String, String> kafkaTemplate() {
return new KafkaTemplate<>(producerFactory());
}
#Bean
public ProducerFactory<String, String> producerFactory() {
Map<String, Object> props = new HashMap<>();
props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");//this.brokerAddress);
props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
// set more properties
return new DefaultKafkaProducerFactory<>(props);
}
}
and in my si-config.xml, i have used the following (ex: topic="getTopic") :
<int-kafka:outbound-channel-adapter
id="kafkaOutboundChannelAdapter" kafka-template="kafkaTemplate"
auto-startup="true" sync="true" channel="inputToKafka" topic="getTopic">
</int-kafka:outbound-channel-adapter>
However, the configuration is unable to pick up the topic name when exposed via bean. But it works fine when i hard code the value of the topic name.
Can someone please suggest what i am doing wrong here?
Does topic within kafka outbound channel accept the value referred as bean?
How do i externalize it as every application using my utility will supply different kafka topic names
The topic attribute is for string value.
However it supports property placeholder resolution:
topic="${kafkaTopic}"
and also SpEL evaluation for aforementioned bean:
topic="#{getTopic}"
Just because this is allowed by the XML parser configuration.
However you may pay attention that KafkaTemplate, which you inject into the <int-kafka:outbound-channel-adapter> has defaultTopic property. Therefore you won't need to worry about that XML.
And one more option available for you is Spring Integration Annotations configuration. Where you can define a #ServiceActivator for the KafkaProducerMessageHandler #Bean:
#ServiceActivator(inputChannel = "inputToKafka")
#Bean
KafkaProducerMessageHandler kafkaOutboundChannelAdapter() {
kafkaOutboundChannelAdapter adapter = new kafkaOutboundChannelAdapter( kafkaTemplate());
adapter.setSync(true);
adapter.setTopicExpression(new LiteralExpression(this.kafkaTopicName));
return adapter;
}
I would like to use the new annotations and features provided in Spring 4.1 for an application that needs a JMS listener.
I've carefully read the notes in the Spring 4.1 JMS improvements post but I continue to miss the relationship between #JmsListener and maybe the DestinationResolver and how I would setup the application to indicate the proper Destination or Endpoint.
Here is the suggested use of #JmsListener
#Component
public class MyService {
#JmsListener(containerFactory = "myContainerFactory", destination = "myQueue")
public void processOrder(String data) { ... }
}
Now, I can't use this in my actual code because the "myQueue" needs to be read from a configuration file using Environment.getProperty().
I can setup an appropriate myContainerFactory with a DestinationResolver but mostly, it seems you would just use DynamicDestinationResolver if you don't need JNDI to lookup a queue in an app server and didn't need to do some custom reply logic. I'm simply trying to understand how Spring wants me to indicate the name of the queue in a parameterized fashion using the #JmsListener annotation.
Further down the blog post, I find a reference to this Configurer:
#Configuration
#EnableJms
public class AppConfig implements JmsListenerConfigurer {
#Override
public void configureJmsListeners(JmsListenerEndpointRegistrar registrar) {
registrar.setDefaultContainerFactory(defaultContainerFactory());
SimpleJmsListenerEndpoint endpoint = new SimpleJmsListenerEndpoint();
endpoint.setDestination("anotherQueue");
endpoint.setMessageListener(message -> {
// processing
});
registrar.registerEndpoint(endpoint);
}
Now, this makes some amount of sense and I could see where this would allow me to set a Destination at runtime from some external string, but this seems to be in conflict with using #JmsListener as it appears to be overriding the annotation in favor of endpoint.setMessageListener in the code above.
Any tips on how to specify the appropriate queue name using #JmsListener?
Also note that depending on use case you can already parameterize using properties file per environment and PropertySourcesPlaceholderConfigurer
#JmsListener(destinations = "${some.key}")
As per https://jira.spring.io/browse/SPR-12289
In case people are using #JmsListener with spring boot, you do not have to configure PropertySourcesPlaceholderConfigurer. It work's out the box
Sample:
class
#JmsListener(destination = "${spring.activemq.queue.name}")
public void receiveEntityMessage(final TextMessage message) {
// process stuff
}
}
application.properties
spring.activemq.queue.name=some.weird.queue.name.that.does.not.exist
Spring boot output
[26-Aug;15:07:53.475]-[INFO ]-[,]-[DefaultMes]-[o.s.j.l.DefaultMessageListenerContainer ]-[931 ]-Successfully refreshed JMS Connection
[26-Aug;15:07:58.589]-[WARN ]-[,]-[DefaultMes]-[o.s.j.l.DefaultMessageListenerContainer ]-[880 ]-Setup of JMS message listener invoker failed for destination 'some.weird.queue.name.that.does.not.exist' - trying to recover. Cause: User user is not authorized to read from some.weird.queue.name.that.does.not.exist
[26-Aug;15:07:59.787]-[INFO ]-[,]-[DefaultMes]-[o.s.j.l.DefaultMessageListenerContainer ]-[931 ]-Successfully refreshed JMS Connection
[26-Aug;15:08:04.881]-[WARN ]-[,]-[DefaultMes]-[o.s.j.l.DefaultMessageListenerContainer ]-[880 ]-Setup of JMS message listener invoker failed for destination 'some.weird.queue.name.that.does.not.exist' - trying to recover. Cause: User user is not authorized to read from some.weird.queue.name.that.does.not.exist
This proves that #JmsListener is able to pickup property values from application.properties without actually setting up any explicit PropertySourcesPlaceholderConfigurer
I hope this helps!
You could eventually do that right now but it's a bit convoluted. You can set a custom JmsListenerEndpointRegistry using JmsListenerConfigurer
#Configuration
#EnableJms
public class AppConfig implements JmsListenerConfigurer {
#Override
public void configureJmsListeners(JmsListenerEndpointRegistrar registrar) {
registrar.setEndpointRegistry(customRegistry());
}
}
and then override the registerListenerContainer method, something like
public void registerListenerContainer(JmsListenerEndpoint endpoint, JmsListenerContainerFactory<?> factory) {
// resolve destination according to whatever -> resolvedDestination
((AbstractJmsListenerEndpoint)endpoint).setDestination(resolvedDestination);
super.registerListenerContainer(endpoint, factory);
}
But we could do better. Please watch/vote for SPR-12280