我正在使用Axon + Spring Boot创建一个简单的应用程序,只是为了确保我在Axon框架中理解基本组件,然后才将其用于实际项目。 有一个应该当我通过CommandGateway命令发送到被称为类TaskAggregate内的@CommandHandler注释的方法,但在运行应用程序后,我得到异常:NoHandlerForCommandException with axon-spring-boot-starter
Exception in thread "main" org.axonframework.commandhandling.NoHandlerForCommandException: No handler was subscribed to command [com.xxx.axontest.task.CreateTaskCommand]
按文档,@CommandHandler注释应该足以将命令hander订阅到命令总线。我想我一定会错过一些东西。你可以看看下面的代码,并指出我正确的方向?
的pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.xxx</groupId>
<artifactId>axon-test</artifactId>
<version>0.0.1-SNAPSHOT</version>
<properties>
<axon.version>3.0.6</axon.version>
</properties>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.7.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.axonframework</groupId>
<artifactId>axon-spring-boot-starter</artifactId>
<version>${axon.version}</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
App.java
package com.xxx.axontest;
import org.axonframework.commandhandling.gateway.CommandGateway;
import org.axonframework.eventsourcing.eventstore.EventStorageEngine;
import org.axonframework.eventsourcing.eventstore.inmemory.InMemoryEventStorageEngine;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;
import com.xxx.axontest.task.CreateTaskCommand;
@SpringBootApplication
public class App {
public static void main(String[] args) {
ConfigurableApplicationContext configurableApplicationContext = SpringApplication.run(App.class, args);
CommandGateway commandGateway = configurableApplicationContext.getBean(CommandGateway.class);
commandGateway.send(new CreateTaskCommand(123, "asd"));
}
@Bean
public EventStorageEngine eventStorageEngine() {
return new InMemoryEventStorageEngine();
}
@Bean
public AnnotationCommandHandlerBeanPostProcessor
annotationCommandHandlerBeanPostProcessor() {
return new AnnotationCommandHandlerBeanPostProcessor();
}
}
CreateTaskCommand.java
package com.xxx.axontest.task;
import org.axonframework.commandhandling.TargetAggregateIdentifier;
public class CreateTaskCommand {
@TargetAggregateIdentifier
private int taskId;
private String name;
public CreateTaskCommand(int taskId, String name) {
this.taskId = taskId;
this.name = name;
}
public int getTaskId() {
return taskId;
}
public String getName() {
return name;
}
}
TaskCreatedEvent.java
package com.xxx.axontest.task;
import org.axonframework.commandhandling.TargetAggregateIdentifier;
public class TaskCreatedEvent {
@TargetAggregateIdentifier
private int taskId;
private String name;
public int getTaskId() {
return taskId;
}
public String getName() {
return name;
}
}
TaskAggregate.java
package com.xxx.axontest.task;
import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import org.axonframework.commandhandling.CommandHandler;
import org.axonframework.commandhandling.model.AggregateIdentifier;
import org.axonframework.commandhandling.model.AggregateLifecycle;
import org.axonframework.eventsourcing.EventSourcingHandler;
import org.axonframework.spring.stereotype.Aggregate;
@AggregateRoot
public class TaskAggregate {
private Logger logger = LogManager.getLogger(TaskCreatedEvent.class);
@AggregateIdentifier
private int taskId;
private String name;
@CommandHandler
public void handleCommand(CreateTaskCommand createTaskCommand) {
logger.info("Command received");
AggregateLifecycle.apply(new TaskCreatedEvent());
}
@EventSourcingHandler
public void onTaskCreatedEvent(TaskCreatedEvent taskCreatedEvent) {
logger.info("Event received");
}
public int getTaskId() {
return taskId;
}
public void setTaskId(int taskId) {
this.taskId = taskId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
在此先感谢。
一件重要的事情:事件和命令应该是不可变的(无设置器) –
从doc:“CommandHandlers需要订阅CommandBusin命令才能接收命令“ –
@ConstantinGalbenu,我根据你的建议删除了setter。 – Rodney