Spring Boot - Kafka Consumer Bean Scope - spring-boot

Question

I'm using a CacheManager in a Spring Boot application with SCOPE_REQUEST scope.
#Bean
#Scope(value = WebApplicationContext.SCOPE_REQUEST, proxyMode = ScopedProxyMode.TARGET_CLASS)
public CacheManager cacheManager() {
return new ConcurrentMapCacheManager();
}
I'm also using Kafka for communication between microservices. Actually I'm receiving an event through a Kafka consumer and I get the following error:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.cacheManager': Scope 'request' is not active for the current thread;
...
Caused by: java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread?
It's clear that the CacheManager bean is missing on the listener thread.
My goal is to have let the Spring Boot/Kafka framework to create the mean for each consumed Kafka events just as it's for the web requests.
I have no idea how I could achive that, could someone help me ?
Thank you so much,
Have a nice day!

Answer 1

#Gary Russel
That's true and false at the same time, meantime I succeed to find a solution, create the below class:
public class KafkaRequestScopeAttributes implements RequestAttributes {
private Map<String, Object> requestAttributeMap = new HashMap<>();
#Override
public Object getAttribute(String name, int scope) {
if (scope == RequestAttributes.SCOPE_REQUEST) {
return this.requestAttributeMap.get(name);
}
return null;
}
#Override
public void setAttribute(String name, Object value, int scope) {
if (scope == RequestAttributes.SCOPE_REQUEST) {
this.requestAttributeMap.put(name, value);
}
}
#Override
public void removeAttribute(String name, int scope) {
if (scope == RequestAttributes.SCOPE_REQUEST) {
this.requestAttributeMap.remove(name);
}
}
#Override
public String[] getAttributeNames(int scope) {
if (scope == RequestAttributes.SCOPE_REQUEST) {
return this.requestAttributeMap.keySet().toArray(new String[0]);
}
return new String[0];
}
#Override
public void registerDestructionCallback(String name, Runnable callback, int scope) {
// Not Supported
}
#Override
public Object resolveReference(String key) {
// Not supported
return null;
}
#Override
public String getSessionId() {
return null;
}
#Override
public Object getSessionMutex() {
return null;
}
}
then add the following two lines into your KafkaListener method's start and end:
RequestContextHolder.setRequestAttributes(new KafkaRequestScopeAttributes());
RequestContextHolder.resetRequestAttributes();
By doing that you can force to create the REQUEST_SCOPE in a Kafka Listener.

Answer 2

Request Scope is for web applications only; it can't be used with Kafka consumers.