AxonConfig类中的axon-mongo 4.5、spring boot 2.4.3和mongodb 4.2出现异常

Question

在运行项目时，我得到以下异常：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 
'axonMongoTemplate' defined in com.springbank.user.core.configuration.AxonConfig: Bean 
instantiation via factory method failed; nested exception is 
org.springframework.beans.BeanInstantiationException: Failed to instantiate 
[org.axonframework.extensions.mongo.MongoTemplate]: Factory method 'axonMongoTemplate' 
threw exception; nested exception is java.lang.IllegalStateException: @Bean method 
AxonConfig.mongo called as bean reference for type [com.mongodb.MongoClient] but overridden
 by non-compatible bean instance of type [com.mongodb.client.internal.MongoClientImpl].
 Overriding bean of same name declared in: class path resource 
[org/springframework/boot/autoconfigure/mongo/MongoAutoConfiguration.class]

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate 
[org.axonframework.extensions.mongo.MongoTemplate]: Factory method 'axonMongoTemplate' 
threw exception; nested exception is java.lang.IllegalStateException: @Bean method 
AxonConfig.mongo called as bean reference for type [com.mongodb.MongoClient] but overridden
 by non-compatible bean instance of type [com.mongodb.client.internal.MongoClientImpl].
 Overriding bean of same name declared in: class path resource
 [org/springframework/boot/autoconfigure/mongo/MongoAutoConfiguration.class]

Caused by: java.lang.IllegalStateException: @Bean method AxonConfig.mongo called as bean 
reference for type [com.mongodb.MongoClient] but overridden by non-compatible bean instance 
of type [com.mongodb.client.internal.MongoClientImpl]. Overriding bean of same name declared 
in: class path resource 
[org/springframework/boot/autoconfigure/mongo/MongoAutoConfiguration.class]

这是我的轴突配置类：

@Configuration
public class AxonConfig {

    @Value("${spring.data.mongodb.host:127.0.0.1}")
    private String mongoHost;

    @Value("${spring.data.mongodb.port:27017}")
    private int mongoPort;

    @Value("${spring.data.mongodb.database:user}")
    private String mongoDatabase;

    @Bean
    public MongoClient mongo() {
        var mongoFactory = new MongoFactory();
        mongoFactory.setMongoAddresses(Collections.singletonList(new ServerAddress(mongoHost, mongoPort)));

        return mongoFactory.createMongo();
    }

    @Bean
    public MongoTemplate axonMongoTemplate() {
        return DefaultMongoTemplate.builder()
                .mongoDatabase(mongo(), mongoDatabase)
                .build();
    }
...
}

我使用的Spring Boot版本和依赖项是：

1. org.springframework.boot：spring-boot-starter-parent：2.4.3
2. org.axonframework：axon-spring-boot-starter：4.5.9
3. org.axonframework.extensions.mongo：axon-mongo：4.3

这是我的application.properties：

#spring
server.port=8082

#mongodb
spring.data.mongodb.host=localhost
spring.data.mongodb.port=27017
spring.data.mongodb.database=user

spring.main.allow-bean-definition-overriding=true
spring.main.allow-circular-references=true

Answer 1

在对依赖版本进行了几次测试后，我发现了彼此不冲突的依赖项。
以下是使用的版本列表：

< li>Java JDK 14版 < Li > spring-boot-starter-parent:2 . 2 . 6 . release < Li > axon-spring-boot-starter:4 . 3 . 1 < li >龙目岛:1.18.20

使用其他版本的spring boot时出现异常。

Answer 2

我认为你可以删除MongoClient Bean，因为Spring Boot已经为你做了。