获取错误 "No serializer found for class org.springframework.data.mongodb.core.convert.DefaultDbRefResolver$LazyLoadingInterceptor"

Question

我正在使用 spring 数据 mongodb，在延迟加载 true 之后我收到错误 "No serializer found for class org.springframework.data.mongodb.core.convert.DefaultDbRefResolver$LazyLoadingInterceptor"。

我的域名class是

public class Preference extends BaseEntity {

    @DBRef(lazy = true)
    User user;

    MetadataEnum preferenceType;


    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }


    public MetadataEnum getPreferenceType() {
        return preferenceType;
    }


    public void setPreferenceType(MetadataEnum preferenceType) {
        this.preferenceType = preferenceType;
    }


    public List<Subtype> getSubtypes() {
        return subtypes;
    }


    public void setSubtypes(List<Subtype> subtypes) {
        this.subtypes = subtypes;
    }

    List<Subtype> subtypes = new ArrayList<Subtype>();


    boolean enableSearch;

}

我浪费了很多时间，但我无法得到合适的答案？谁能帮我重新爱上它？提前致谢

Answer 1

关闭该 bean 的序列化程序，因为使用 @DBRef 延迟加载仅适用于实体列表，jackson 自动序列化 @DBRef(lazy = true) 列表用户，但不适用于 '@DBRef(lazy = true) User 用户.因此，您必须手动序列化它或关闭该 bean 的序列化程序。

Answer 2

根据您的要求添加此配置代码

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.core.convert.LazyLoadingProxy;

import com.fasterxml.jackson.core.Version;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;

@Configuration
public class LazyLoadingSerializationConfig {

    @Bean
    public ObjectMapper objectMapper() {

        ObjectMapper om = new ObjectMapper();
        final SimpleModule module = new SimpleModule("<your entity>", new Version(1, 0, 0,null));

        module.addSerializer(LazyLoadingProxy.class, new LazyLoadingSerializer());
        om.registerModule(module);

        return om;
    }

}

和

import java.io.IOException;

import org.springframework.data.mongodb.core.convert.LazyLoadingProxy;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

public class LazyLoadingSerializer extends JsonSerializer<LazyLoadingProxy> {

    @Override
    public void serialize(LazyLoadingProxy value, JsonGenerator jgen,
        SerializerProvider provider) throws IOException,
        JsonProcessingException {

        jgen.writeStartObject();
        jgen.writeStringField("id", value.toDBRef().getId().toString());
        jgen.writeEndObject();
    }
}

希望对您有所帮助！

获取错误 "No serializer found for class org.springframework.data.mongodb.core.convert.DefaultDbRefResolver$LazyLoadingInterceptor"

Getting error "No serializer found for class org.springframework.data.mongodb.core.convert.DefaultDbRefResolver$LazyLoadingInterceptor"

mongodb

spring-data-mongodb