一、情景
SpringBoot项目中，引入Mongo，项目启动时，会自动创建配置的相关Collection信息。如果代码中有Document保存信息，则会自动创建Document及相关字段，默认创建的字段包括字段：_class。根据业务需求，则不需要保存该字段。
二、代码实现
设置Mongo配置信息
import org.springframework.beans.factory.BeanFactory; import org.springframework.beans.factory.NoSuchBeanDefinitionException; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.mongodb.MongoDbFactory; import org.springframework.data.mongodb.core.convert.*; import org.springframework.data.mongodb.core.mapping.MongoMappingContext; /** * @description: * When using spring data mongo it by default adds a _class key to your collection to be able to handle inheritance. * But if your domain model is simple and flat, you can remove it by overriding the default MappingMongoConverter */ @Configuration public class MongoConfig { @Bean public MappingMongoConverter mappingMongoConverter(MongoDbFactory factory, MongoMappingContext context, BeanFactory beanFactory) { DbRefResolver dbRefResolver = new DefaultDbRefResolver(factory); MappingMongoConverter mappingConverter = new MappingMongoConverter(dbRefResolver, context); try { mappingConverter.setCustomConversions(beanFactory.getBean(CustomConversions.class)); } catch (NoSuchBeanDefinitionException ignore) { } // Don't save _class to mongo mappingConverter.setTypeMapper(new DefaultMongoTypeMapper(null)); return mappingConverter; } }
