org.axonframework.common.AxonConfigurationException: A default XStreamSerializer is used for snapshots, without specifying the security context

Question

I am using Spring Boot and CQRS using AXONIQ Framework concepts using: https://www.udemy.com/course/master-spring-boot-microservices-with-cqrs-event-sourcing/learn/lecture/23432536#overview.

I am getting the below error when trying to start the app.

Error:

org.axonframework.common.AxonConfigurationException: A default XStreamSerializer is used for snapshots, without specifying the security context
    at org.axonframework.eventsourcing.eventstore.AbstractEventStorageEngine$Builder.validate(AbstractEventStorageEngine.java:369) ~[axon-eventsourcing-4.5.8.jar:4.5.8]
    at org.axonframework.eventsourcing.eventstore.BatchingEventStorageEngine$Builder.validate(BatchingEventStorageEngine.java:224) ~[axon-eventsourcing-4.5.8.jar:4.5.8]
    at org.axonframework.extensions.mongo.eventsourcing.eventstore.MongoEventStorageEngine$Builder.validate(MongoEventStorageEngine.java:286) ~[axon-mongo-4.4.jar:4.4]
    at org.axonframework.eventsourcing.eventstore.AbstractEventStorageEngine.<init>(AbstractEventStorageEngine.java:74) ~[axon-eventsourcing-4.5.8.jar:4.5.8]
    at org.axonframework.eventsourcing.eventstore.BatchingEventStorageEngine.<init>(BatchingEventStorageEngine.java:62) ~[axon-eventsourcing-4.5.8.jar:4.5.8]
    at org.axonframework.extensions.mongo.eventsourcing.eventstore.MongoEventStorageEngine.<init>(MongoEventStorageEngine.java:64) ~[axon-mongo-4.4.jar:4.4]
    at org.axonframework.extensions.mongo.eventsourcing.eventstore.MongoEventStorageEngine$Builder.build(MongoEventStorageEngine.java:275) ~[axon-mongo-4.4.jar:4.4]
    at com.example.demo.configuration.AxonConfig.eventStorageEngine(AxonConfig.java:70) ~[classes/:na]
    at com.example.demo.configuration.AxonConfig$$EnhancerBySpringCGLIB$$42613698.CGLIB$eventStorageEngine$4(<generated>) ~[classes/:na]
    at com.example.demo.configuration.AxonConfig$$EnhancerBySpringCGLIB$$42613698$$FastClassBySpringCGLIB$$202fc6aa.invoke(<generated>) ~[classes/:na]
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) ~[spring-core-5.3.20.jar:5.3.20]
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331) ~[spring-context-5.3.20.jar:5.3.20]
    at com.example.demo.configuration.AxonConfig$$EnhancerBySpringCGLIB$$42613698.eventStorageEngine(<generated>) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:486) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1352) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:582) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:953) ~[spring-beans-5.3.20.jar:5.3.20]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918) ~[spring-context-5.3.20.jar:5.3.20]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.20.jar:5.3.20]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147) ~[spring-boot-2.7.0.jar:2.7.0]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:734) ~[spring-boot-2.7.0.jar:2.7.0]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408) ~[spring-boot-2.7.0.jar:2.7.0]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:308) ~[spring-boot-2.7.0.jar:2.7.0]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) ~[spring-boot-2.7.0.jar:2.7.0]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) ~[spring-boot-2.7.0.jar:2.7.0]
    at com.example.demo.UserCommandApplication.main(UserCommandApplication.java:13) ~[classes/:na]

AxonConfig.java

package com.example.demo.configuration;

import com.mongodb.ServerAddress;
import com.mongodb.client.MongoClient;
import org.axonframework.eventhandling.tokenstore.TokenStore;
import org.axonframework.eventsourcing.EventCountSnapshotTriggerDefinition;
import org.axonframework.eventsourcing.SnapshotTriggerDefinition;
import org.axonframework.eventsourcing.Snapshotter;
import org.axonframework.eventsourcing.eventstore.EmbeddedEventStore;
import org.axonframework.eventsourcing.eventstore.EventStorageEngine;
import org.axonframework.eventsourcing.eventstore.EventStore;
import org.axonframework.extensions.mongo.DefaultMongoTemplate;
import org.axonframework.extensions.mongo.MongoTemplate;
import org.axonframework.extensions.mongo.eventsourcing.eventstore.MongoEventStorageEngine;
import org.axonframework.extensions.mongo.eventsourcing.eventstore.MongoFactory;
import org.axonframework.extensions.mongo.eventsourcing.eventstore.MongoSettingsFactory;
import org.axonframework.extensions.mongo.eventsourcing.tokenstore.MongoTokenStore;
import org.axonframework.serialization.Serializer;
import org.axonframework.spring.config.AxonConfiguration;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.List;

@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-api}")
    private String mongoDatabase;

    @Bean
    public MongoClient mongoClient() {
        MongoFactory mongoFactory = new MongoFactory();
        MongoSettingsFactory mongoSettingsFactory = new MongoSettingsFactory();
        mongoSettingsFactory.setMongoAddresses(List.of(new ServerAddress(mongoHost, mongoPort)));
        mongoFactory.setMongoClientSettings(mongoSettingsFactory.createMongoClientSettings());
        return mongoFactory.createMongo();
    }

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

    @Bean
    public TokenStore tokenStore(Serializer serializer) {
        return MongoTokenStore.builder()
                .mongoTemplate(axonMongoTemplate())
                .serializer(serializer)
                .build();
    }

    @Bean
    public EventStorageEngine eventStorageEngine() {
        return MongoEventStorageEngine.builder()
                .mongoTemplate(
                        DefaultMongoTemplate.builder()
                                .mongoDatabase(mongoClient())
                                .build()
                )
                .build();
    }

    @Bean
    public EmbeddedEventStore eventStore(AxonConfiguration configuration) {
        return EmbeddedEventStore.builder()
                .storageEngine(eventStorageEngine())
                .messageMonitor(configuration.messageMonitor(EventStore.class, "eventStore"))
                .build();
    }
}

Answer 1

Adding something like the Bean underneath to theAxonConfiguration class should hopefully fix it.

    @Bean
    @Qualifier("defaultAxonXStream")
    public XStream xStream() {
        XStream xStream = new XStream();

        xStream.allowTypesByWildcard(new String[]{
                "java.util.**",
                "tech.gklijs.tech.**"
        });
        return xStream;
    }