SpringBoot - BeanDefinitionOverrideException: Invalid bean definition

问题

I am trying to setup DynamoDB locally with Spring Boot. Initially I got the setup working and was able to write/save to DynamoDB via a repository. From that point I added more classes to build my application. Now when I try to start my application, I get the following exception:

org.springframework.beans.factory.support.BeanDefinitionOverrideException: Invalid bean definition with name 'agentRepository' defined in null: Cannot register bean definition [Root bean: class [org.socialsignin.spring.data.dynamodb.repository.support.DynamoDBRepositoryFactoryBean]; scope=; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null] for bean 'agentRepository': There is already [Root bean: class [org.socialsignin.spring.data.dynamodb.repository.support.DynamoDBRepositoryFactoryBean]; scope=; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null] bound.

I have searched SO and internet extensively but there were no any useful solution to this. The error message is misleading as well.

My project is of the following hierarchy

ai.test.as
  - as
      - agent
          - business
          - intent
          - exception
          - Agent.java
          - AgentDTO.java
          - AgentRespository.java
          - AgentController.java
          - AgentService.java
          - AgentServiceImpl.java
  - config
     - DynamoDBConfig.java

DynamoDBConfig.java

package ai.test.as.config;

import ai.test.as.agent.AgentRepository;
import ai.test.as.agent.intent.template.TemplateRepository;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient;
import org.socialsignin.spring.data.dynamodb.repository.config.EnableDynamoDBRepositories;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableDynamoDBRepositories(basePackageClasses = {AgentRepository.class})
public class DynamoDBConfig
{
    @Value("${aws.dynamodb.endpoint}")
    private String dynamoDBEndpoint;

    @Value("${aws.auth.accesskey}")
    private String awsAccessKey;

    @Value("${aws.auth.secretkey}")
    private String awsSecretKey;

    @Bean
    public AmazonDynamoDB amazonDynamoDB()
    {
        AmazonDynamoDB dynamoDB = new AmazonDynamoDBClient(getAwsCredentials());
        dynamoDB.setEndpoint(dynamoDBEndpoint);

        return dynamoDB;
    }

    @Bean
    public AWSCredentials getAwsCredentials()
    {
        return new BasicAWSCredentials(awsAccessKey, awsSecretKey);
    }
}

AgentRepository.java

package ai.test.as.agent;

import ai.test.as.agent.Agent;
import org.socialsignin.spring.data.dynamodb.repository.EnableScan;
import org.springframework.data.repository.CrudRepository;

@EnableScan
public interface AgentRepository extends CrudRepository<Agent, String>
{
}

AgentController.java (Where AgentRepository is used)

@RestController
@RequestMapping(value = "/v1/agents")
public class AgentController
{
    @Autowired
    private AgentRepository agentRepository;

    @RequestMapping(value = "/test", method = RequestMethod.POST)
    public void test()
    {
        Agent agent = new Agent();
        agent.setAgentNumber("123456");
        agent.setId(1);

        agentRepository.save(agent);
    }
}

Spring suggests the following: > The bean 'agentRepository', defined in null, could not be registered. A bean with that name has already been defined in null and overriding is disabled.

What does null mean here? Is it because something wrong in my application config? Also how is it possible that it is already registered?

Please give me some pointers because I so confused about my next steps.

回答1:

Bean overriding has to be enabled since Spring Boot 2.1,

https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.1-Release-Notes

Bean Overriding

Bean overriding has been disabled by default to prevent a bean being accidentally overridden. If you are relying on overriding, you will need to set spring.main.allow-bean-definition-overriding to true.

Set

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

or yml,

spring:
   main:
     allow-bean-definition-overriding: true

to enable overriding again.

Edit,

Bean Overriding is based of the name of the bean not its type. e.g.

@Bean
public ClassA class(){
   return new ClassA();
}

@Bean
public ClassB class(){
   return new ClassB();
}

Will cause this error in > 2.1, by default bean names are taken from the method name. Renaming the method or adding the name attribute to the Bean annotation will be a valid fix.

来源：https://stackoverflow.com/questions/53723303/springboot-beandefinitionoverrideexception-invalid-bean-definition