org.springframework.kafka.config.KafkaListenerEndpointRegistrar Maven / Gradle / Ivy
/*
* Copyright 2014-2020 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.kafka.config;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.kafka.annotation.KafkaListenerAnnotationBeanPostProcessor;
import org.springframework.lang.Nullable;
import org.springframework.messaging.handler.annotation.support.MessageHandlerMethodFactory;
import org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver;
import org.springframework.util.Assert;
import org.springframework.validation.Validator;
/**
* Helper bean for registering {@link KafkaListenerEndpoint} with
* a {@link KafkaListenerEndpointRegistry}.
*
* @author Stephane Nicoll
* @author Juergen Hoeller
* @author Artem Bilan
* @author Gary Russell
* @author Filip Halemba
*
* @see org.springframework.kafka.annotation.KafkaListenerConfigurer
*/
public class KafkaListenerEndpointRegistrar implements BeanFactoryAware, InitializingBean {
private final List endpointDescriptors = new ArrayList<>();
private List customMethodArgumentResolvers = new ArrayList<>();
private KafkaListenerEndpointRegistry endpointRegistry;
private MessageHandlerMethodFactory messageHandlerMethodFactory;
private KafkaListenerContainerFactory containerFactory;
private String containerFactoryBeanName;
private BeanFactory beanFactory;
private boolean startImmediately;
private Validator validator;
/**
* Set the {@link KafkaListenerEndpointRegistry} instance to use.
* @param endpointRegistry the {@link KafkaListenerEndpointRegistry} instance to use.
*/
public void setEndpointRegistry(KafkaListenerEndpointRegistry endpointRegistry) {
this.endpointRegistry = endpointRegistry;
}
/**
* Return the {@link KafkaListenerEndpointRegistry} instance for this
* registrar, may be {@code null}.
* @return the {@link KafkaListenerEndpointRegistry} instance for this
* registrar, may be {@code null}.
*/
public KafkaListenerEndpointRegistry getEndpointRegistry() {
return this.endpointRegistry;
}
/**
* Return the list of {@link HandlerMethodArgumentResolver}.
* @return the list of {@link HandlerMethodArgumentResolver}.
* @since 2.4.2
*/
public List getCustomMethodArgumentResolvers() {
return Collections.unmodifiableList(this.customMethodArgumentResolvers);
}
/**
* Add custom methods arguments resolvers to {@link KafkaListenerAnnotationBeanPostProcessor}
* Default empty list.
* @param methodArgumentResolvers the methodArgumentResolvers to assign.
* @since 2.4.2
*/
public void setCustomMethodArgumentResolvers(HandlerMethodArgumentResolver... methodArgumentResolvers) {
this.customMethodArgumentResolvers = Arrays.asList(methodArgumentResolvers);
}
/**
* Set the {@link MessageHandlerMethodFactory} to use to configure the message
* listener responsible to serve an endpoint detected by this processor.
* By default,
* {@link org.springframework.messaging.handler.annotation.support.DefaultMessageHandlerMethodFactory}
* is used and it can be configured further to support additional method arguments
* or to customize conversion and validation support. See
* {@link org.springframework.messaging.handler.annotation.support.DefaultMessageHandlerMethodFactory}
* javadoc for more details.
* @param kafkaHandlerMethodFactory the {@link MessageHandlerMethodFactory} instance.
*/
public void setMessageHandlerMethodFactory(MessageHandlerMethodFactory kafkaHandlerMethodFactory) {
Assert.isNull(this.validator,
"A validator cannot be provided with a custom message handler factory");
this.messageHandlerMethodFactory = kafkaHandlerMethodFactory;
}
/**
* Return the custom {@link MessageHandlerMethodFactory} to use, if any.
* @return the custom {@link MessageHandlerMethodFactory} to use, if any.
*/
public MessageHandlerMethodFactory getMessageHandlerMethodFactory() {
return this.messageHandlerMethodFactory;
}
/**
* Set the {@link KafkaListenerContainerFactory} to use in case a {@link KafkaListenerEndpoint}
* is registered with a {@code null} container factory.
*
Alternatively, the bean name of the {@link KafkaListenerContainerFactory} to use
* can be specified for a lazy lookup, see {@link #setContainerFactoryBeanName}.
* @param containerFactory the {@link KafkaListenerContainerFactory} instance.
*/
public void setContainerFactory(KafkaListenerContainerFactory containerFactory) {
this.containerFactory = containerFactory;
}
/**
* Set the bean name of the {@link KafkaListenerContainerFactory} to use in case
* a {@link KafkaListenerEndpoint} is registered with a {@code null} container factory.
* Alternatively, the container factory instance can be registered directly:
* see {@link #setContainerFactory(KafkaListenerContainerFactory)}.
* @param containerFactoryBeanName the {@link KafkaListenerContainerFactory} bean name.
* @see #setBeanFactory
*/
public void setContainerFactoryBeanName(String containerFactoryBeanName) {
this.containerFactoryBeanName = containerFactoryBeanName;
}
/**
* A {@link BeanFactory} only needs to be available in conjunction with
* {@link #setContainerFactoryBeanName}.
* @param beanFactory the {@link BeanFactory} instance.
*/
@Override
public void setBeanFactory(BeanFactory beanFactory) {
this.beanFactory = beanFactory;
}
/**
* Get the validator, if supplied.
* @return the validator.
* @since 2.2
*/
@Nullable
public Validator getValidator() {
return this.validator;
}
/**
* Set the validator to use if the default message handler factory is used.
* @param validator the validator.
* @since 2.2
*/
public void setValidator(Validator validator) {
Assert.isNull(this.messageHandlerMethodFactory,
"A validator cannot be provided with a custom message handler factory");
this.validator = validator;
}
@Override
public void afterPropertiesSet() {
registerAllEndpoints();
}
protected void registerAllEndpoints() {
synchronized (this.endpointDescriptors) {
for (KafkaListenerEndpointDescriptor descriptor : this.endpointDescriptors) {
this.endpointRegistry.registerListenerContainer(
descriptor.endpoint, resolveContainerFactory(descriptor));
}
this.startImmediately = true; // trigger immediate startup
}
}
private KafkaListenerContainerFactory resolveContainerFactory(KafkaListenerEndpointDescriptor descriptor) {
if (descriptor.containerFactory != null) {
return descriptor.containerFactory;
}
else if (this.containerFactory != null) {
return this.containerFactory;
}
else if (this.containerFactoryBeanName != null) {
Assert.state(this.beanFactory != null, "BeanFactory must be set to obtain container factory by bean name");
this.containerFactory = this.beanFactory.getBean(
this.containerFactoryBeanName, KafkaListenerContainerFactory.class);
return this.containerFactory; // Consider changing this if live change of the factory is required
}
else {
throw new IllegalStateException("Could not resolve the " +
KafkaListenerContainerFactory.class.getSimpleName() + " to use for [" +
descriptor.endpoint + "] no factory was given and no default is set.");
}
}
/**
* Register a new {@link KafkaListenerEndpoint} alongside the
* {@link KafkaListenerContainerFactory} to use to create the underlying container.
*
The {@code factory} may be {@code null} if the default factory has to be
* used for that endpoint.
* @param endpoint the {@link KafkaListenerEndpoint} instance to register.
* @param factory the {@link KafkaListenerContainerFactory} to use.
*/
public void registerEndpoint(KafkaListenerEndpoint endpoint, KafkaListenerContainerFactory factory) {
Assert.notNull(endpoint, "Endpoint must be set");
Assert.hasText(endpoint.getId(), "Endpoint id must be set");
// Factory may be null, we defer the resolution right before actually creating the container
KafkaListenerEndpointDescriptor descriptor = new KafkaListenerEndpointDescriptor(endpoint, factory);
synchronized (this.endpointDescriptors) {
if (this.startImmediately) { // Register and start immediately
this.endpointRegistry.registerListenerContainer(descriptor.endpoint,
resolveContainerFactory(descriptor), true);
}
else {
this.endpointDescriptors.add(descriptor);
}
}
}
/**
* Register a new {@link KafkaListenerEndpoint} using the default
* {@link KafkaListenerContainerFactory} to create the underlying container.
* @param endpoint the {@link KafkaListenerEndpoint} instance to register.
* @see #setContainerFactory(KafkaListenerContainerFactory)
* @see #registerEndpoint(KafkaListenerEndpoint, KafkaListenerContainerFactory)
*/
public void registerEndpoint(KafkaListenerEndpoint endpoint) {
registerEndpoint(endpoint, null);
}
private static final class KafkaListenerEndpointDescriptor {
private final KafkaListenerEndpoint endpoint;
private final KafkaListenerContainerFactory containerFactory;
private KafkaListenerEndpointDescriptor(KafkaListenerEndpoint endpoint,
KafkaListenerContainerFactory containerFactory) {
this.endpoint = endpoint;
this.containerFactory = containerFactory;
}
}
}