SpringBoot MongoDB 색인 충돌 분석 및 해결 방법

@Document(collection = "T_MDevice")
public class MDevice {

  @Id
  private String id;

  @Indexed(unique=true)
  private String deviceId;

db.getCollection('T_MDevice').getIndexes()

>>
[
  {
    "v" : 1,
    "key" : {
      "_id" : 1
    },
    "name" : "_id_",
    "ns" : "appdb.T_MDevice"
  },
  {
    "v" : 1,
    "key" : {
      "deviceId" : 1
    },
    "name" : "deviceId",
    "ns" : "appdb.T_MDevice"
  }
]

public MongoPersistentEntityIndexCreator(MongoMappingContext mappingContext, MongoDbFactory mongoDbFactory,
      IndexResolver indexResolver) {
    ...
    //        
    for (MongoPersistentEntity<?> entity : mappingContext.getPersistentEntities()) {
      checkForIndexes(entity);
    }
  }

 public void onApplicationEvent(MappingContextEvent<?, ?> event) {

    if (!event.wasEmittedBy(mappingContext)) {
      return;
    }

    PersistentEntity<?, ?> entity = event.getPersistentEntity();

    // Double check type as Spring infrastructure does not consider nested generics
    if (entity instanceof MongoPersistentEntity) {
      //        
      checkForIndexes((MongoPersistentEntity<?>) entity);
    }
  }

  public MongoTemplate(MongoDbFactory mongoDbFactory, MongoConverter mongoConverter) {

    Assert.notNull(mongoDbFactory);

    this.mongoDbFactory = mongoDbFactory;
    this.exceptionTranslator = mongoDbFactory.getExceptionTranslator();
    this.mongoConverter = mongoConverter == null ? getDefaultMongoConverter(mongoDbFactory) : mongoConverter;
    ...

    // We always have a mapping context in the converter, whether it's a simple one or not
    mappingContext = this.mongoConverter.getMappingContext();
    // We create indexes based on mapping events
    if (null != mappingContext && mappingContext instanceof MongoMappingContext) {
      indexCreator = new MongoPersistentEntityIndexCreator((MongoMappingContext) mappingContext, mongoDbFactory);
      eventPublisher = new MongoMappingEventPublisher(indexCreator);
      if (mappingContext instanceof ApplicationEventPublisherAware) {
        ((ApplicationEventPublisherAware) mappingContext).setApplicationEventPublisher(eventPublisher);
      }
    }
  }


  ...
  //MongoTemplate    ApplicationContextAware， ApplicationContext        
  public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {

    prepareIndexCreator(applicationContext);

    eventPublisher = applicationContext;
    if (mappingContext instanceof ApplicationEventPublisherAware) {
      //MappingContext      ， ApplicationContext  
      ((ApplicationEventPublisherAware) mappingContext).setApplicationEventPublisher(eventPublisher);
    }
    resourceLoader = applicationContext;
  }

  ...
  //      
  private void prepareIndexCreator(ApplicationContext context) {

    String[] indexCreators = context.getBeanNamesForType(MongoPersistentEntityIndexCreator.class);

    for (String creator : indexCreators) {
      MongoPersistentEntityIndexCreator creatorBean = context.getBean(creator, MongoPersistentEntityIndexCreator.class);
      if (creatorBean.isIndexCreatorFor(mappingContext)) {
        return;
      }
    }

    if (context instanceof ConfigurableApplicationContext) {
      //  IndexCreator    ApplicationContext   
      ((ConfigurableApplicationContext) context).addApplicationListener(indexCreator);
    }
  }

 @Bean
  public MongoMappingContext mappingContext() {
    return new MongoMappingContext();
  }

  //    MappingContext     MongoTemplate
  @Bean
  public MongoTemplate mongoTemplate(MongoDbFactory mongoDbFactory, MongoMappingContext mappingContext) {
    MappingMongoConverter converter = new MappingMongoConverter(new DefaultDbRefResolver(mongoDbFactory),
        mappingContext);
    converter.setTypeMapper(new DefaultMongoTypeMapper(null));

    MongoTemplate mongoTemplate = new MongoTemplate(mongoDbFactory, converter);

    return mongoTemplate;
  }

  //    IndexCreator  
  @Component
  public static class CustomIndexCreator extends MongoPersistentEntityIndexCreator {

    //      MappingContext
    public CustomIndexCreator(MongoMappingContext mappingContext, MongoDbFactory mongoDbFactory) {
      super(mappingContext, mongoDbFactory);
    }

    public void onApplicationEvent(MappingContextEvent<?, ?> event) {
      PersistentEntity<?, ?> entity = event.getPersistentEntity();

      //   Mongo   
      if (entity instanceof MongoPersistentEntity) {
        System.out.println("Detected MongoEntity " + entity.getName());
        
        //       ..
      }
    }
  }