Spring Data Entity中的UUID以传统UUID的形式存储在MongoDB中。

Question

我正在将一些数据转储到我的MongoDb中，并在此过程中生成UUID。在集合中，这个UUID字段存储为LUUID（遗留UUID - 类型3），我不知道如何避免这种情况，因为我希望格式为标准UUID（类型4）。

实体：

@Document(collection = "sms")
public class SmsEntity {
    ...
    private UUID ubmMessageSid;  // <- this field gets stored as LUUID
    ...

    public static class Builder {
    ...
        private UUID ubmMessageSid;
    ...

        public Builder ubmMessageSid(UUID ubmMessageSid) {
            this.ubmMessageSid = ubmMessageSid;
            return this;
        }

        public SmsEntity build() {return new SmsEntity(this);}
    }
}

代码库：

@Repository
public interface SmsRepository extends CrudRepository<SmsEntity, String> {
}

存储此实体的服务：

...
var ubmId = UUID.randomUUID();
var smsEntity = SmsEntity.builder()
    .ubmMessageSid(ubmId)
    ...
    .build();
repository.save(smsEntity);

我需要注释或配置什么来将UUID存储为二进制/类型4吗？

- EngJon

Answer 1

在Spring Boot 2中，针对Spring MongoDB 3.x，您可以使用自动配置属性进行设置：

# Options: unspecified, standard, c_sharp_legacy, java_legacy, python_legacy
spring.data.mongodb.uuid-representation=standard

- tlogbon

Answer 2

在Spring Data Mongo的3.x版本中，MongoClient已被MongoClientSettings取代:

CodecRegistry codecRegistry =
  CodecRegistries.fromRegistries(CodecRegistries.fromCodecs(new UuidCodec(UuidRepresentation.JAVA_LEGACY)),
    MongoClientSettings.getDefaultCodecRegistry());

return new MongoClient(new ServerAddress(address, port), MongoClientSettings.builder().codecRegistry(codecRegistry).build());

- Azyl

---

我认为你不能使用return new MongoClient(...)，而是需要使用return MongoClients.create(...);，更多信息请参见此处。 - Zap

Answer 3

您可以在Mongo配置中设置UUID编解码器，这将使用类型4编解码器保留您的UUID。您需要执行的代码如下：

CodecRegistries.fromRegistries(CodecRegistries.fromCodecs(new UuidCodec(UuidRepresentation.STANDARD)),
                        MongoClient.getDefaultCodecRegistry());
        return new MongoClient(new ServerAddress(address, port), MongoClientOptions.builder().codecRegistry(codecRegistry).build());

以下是完整的类，以防万一：

```

这里是完整的类，以防万一：

```

import com.mongodb.MongoClient;
import com.mongodb.MongoClientOptions;
import com.mongodb.ServerAddress;
import org.bson.UuidRepresentation;
import org.bson.codecs.UuidCodec;
import org.bson.codecs.configuration.CodecRegistries;
import org.bson.codecs.configuration.CodecRegistry;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.config.AbstractMongoConfiguration;
import org.springframework.data.mongodb.core.mapping.event.ValidatingMongoEventListener;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;
import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;

@Configuration
@EnableAutoConfiguration
@EnableMongoRepositories(basePackages = "com.yourpackage.repositories")
public class MongoConfig extends AbstractMongoConfiguration {
    @Value("${mongo.database}")
    String database;
    @Value("${mongo.address}")
    String address;
    @Value("${mongo.port}")
    Integer port;

    @Override
    protected String getDatabaseName() {
        return database;
    }

    @Override
    public MongoClient mongoClient() {
        CodecRegistry codecRegistry =
                CodecRegistries.fromRegistries(CodecRegistries.fromCodecs(new UuidCodec(UuidRepresentation.STANDARD)),
                        MongoClient.getDefaultCodecRegistry());
        return new MongoClient(new ServerAddress(address, port), MongoClientOptions.builder().codecRegistry(codecRegistry).build());
    }

    @Bean
    public LocalValidatorFactoryBean localValidatorFactoryBean() {
        return new LocalValidatorFactoryBean();
    }

    @Bean
    public ValidatingMongoEventListener validatingMongoEventListener() {
        return new ValidatingMongoEventListener(localValidatorFactoryBean());
    }
}

注意：随着新的Spring Boot版本2.2.0.RELEASE，AbstractMongoConfiguration已经过时，不再起作用。我为此发布了一篇文章，也许这是一个bug，或者有人知道答案：Spring Boot标准UUID编解码器与AbstractMongoClientConfiguration不兼容。

- Spotvice

Answer 4

在我的情况下，application.yml 文件中的属性与使用 CodecRegistries 的属性一样都无法正常工作。我的解决方案是：

MongoConfig.java:

    @Bean
    public MongoClient mongoClient() {
        MongoClientSettings.Builder builder = MongoClientSettings.builder();
        builder.uuidRepresentation(UuidRepresentation.JAVA_LEGACY);
        return MongoClients.create(builder.build());
    }

- Zap