Axon Framework可以与ActiveMQ集成,以下是一个简单的代码示例来说明如何使用Axon Framework与ActiveMQ进行集成:
首先,确保在项目的依赖管理中包含Axon Framework和ActiveMQ的相关依赖项。在pom.xml文件中添加以下依赖:
org.axonframework
axon-spring-boot-starter
4.5.3
org.apache.activemq
activemq-broker
5.15.9
org.apache.activemq
activemq-client
5.15.9
接下来,创建一个配置类来配置Axon Framework和ActiveMQ的集成。在该类中,我们将配置一个用于处理命令和事件的CommandBus和EventBus,并使用ActiveMQ作为消息传递的中间件。
@Configuration
@EnableAutoConfiguration
public class AxonConfig {
@Bean
public CommandBus commandBus() {
return new SimpleCommandBus();
}
@Bean
public EventBus eventBus() {
return new SimpleEventBus();
}
@Bean
public EventStorageEngine eventStorageEngine() {
return new InMemoryEventStorageEngine();
}
@Bean
public ConnectionFactory connectionFactory() {
return new ActiveMQConnectionFactory("tcp://localhost:61616");
}
@Bean
public SpringAMQPMessageSource messageSource(ConnectionFactory connectionFactory) {
return new SpringAMQPMessageSource(new DefaultAMQPMessageConverter(), connectionFactory);
}
@Bean
public DefaultAMQPMessageConverter messageConverter() {
return DefaultAMQPMessageConverter.builder()
.withContentType(MessageProperties.CONTENT_TYPE_JSON)
.build();
}
@Bean
public SubscribableMessageSource eventSubscribableMessageSource(SpringAMQPMessageSource springAMQPMessageSource) {
return new DefaultSubscribableMessageSource<>(springAMQPMessageSource);
}
@Bean
public MessageMonitor> messageMonitor() {
return NoOpMessageMonitor.INSTANCE;
}
@Bean
public SpringAMQPPublisher publisher(EventBus eventBus, MessageMonitor> messageMonitor) {
return new SpringAMQPPublisher(eventBus, messageMonitor);
}
@Bean
public SpringAMQPConsumerConfiguration springAMQPConsumerConfiguration() {
SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy();
retryPolicy.setMaxAttempts(3);
FixedBackOffPolicy backOffPolicy = new FixedBackOffPolicy();
backOffPolicy.setBackOffPeriod(1000); // 1 second
RetryTemplate retryTemplate = new RetryTemplate();
retryTemplate.setRetryPolicy(retryPolicy);
retryTemplate.setBackOffPolicy(backOffPolicy);
SpringAMQPConsumerConfiguration configuration = new SpringAMQPConsumerConfiguration();
configuration.setRetryTemplate(retryTemplate);
configuration.setConcurrentConsumers(1); // adjust as needed
return configuration;
}
@Bean
public SpringAMQPMessageSource springAMQPMessageSource(ConnectionFactory connectionFactory) {
return new SpringAMQPMessageSource(new DefaultAMQPMessageConverter(), connectionFactory);
}
@Bean
public SpringAMQPMessageConverter springAMQPMessageConverter() {
return DefaultSpringAMQPMessageConverter.builder()
.messageConverter(messageConverter())
.build();
}
@Bean
public SpringAMQPMessageSource eventSource(
SubscribableMessageSource eventSubscribableMessageSource,
SpringAMQPMessageConverter springAMQPMessageConverter,
SpringAMQPConsumerConfiguration springAMQPConsumerConfiguration) {
return new SpringAMQPMessageSource(eventSubscribableMessageSource, springAMQPMessageConverter,
springAMQPConsumerConfiguration);
}
}
最后,在你的应用程序中,你可以使用Axon Framework提供的注解和类来定义聚合根、命令和事件。例如,以下是一个简单的聚合根示例:
@Aggregate
public class MyAggregate {
@AggregateIdentifier
private String id;
public MyAggregate() {
// Required by Axon