Spring Boot：从PostgreSQL JSON列反序列化POJO时忽略未知字段

针对PostgreSQL jsonb字段映射到DTO时因第三方API新增属性导致的UnrecognizedPropertyException，以下是几种可行的解决方案：

方案1：自定义JsonBinaryType类型 #

创建一个继承JsonBinaryType的自定义类型，在构造方法中配置忽略未知属性的ObjectMapper：

public class CustomJsonBinaryType extends JsonBinaryType {
    public CustomJsonBinaryType() {
        super();
        ObjectMapper mapper = new ObjectMapper();
        // 关闭未知属性触发反序列化失败的特性
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        setObjectMapper(mapper);
    }
}

然后在实体类中使用这个自定义类型：

@Entity
@TypeDef(name = "customJsonb", typeClass = CustomJsonBinaryType.class)
public class A {
    // 其他字段

    @Type(type = "customJsonb")
    @Column(name = "jsonBody", columnDefinition = "jsonb")
    private SomeModel jsonBody;
}

方案2：全局配置Hibernate的Jackson ObjectMapper #

通过Spring Boot的HibernatePropertiesCustomizer全局配置Hibernate使用的ObjectMapper：

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.hibernate.type.jackson.JacksonJsonBinaryType;
import org.springframework.boot.autoconfigure.orm.jpa.HibernatePropertiesCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class HibernateJacksonConfig {

    @Bean
    public HibernatePropertiesCustomizer hibernateJacksonCustomizer() {
        return hibernateProperties -> {
            ObjectMapper objectMapper = new ObjectMapper();
            objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
            // 为JsonBinaryType指定配置好的ObjectMapper
            hibernateProperties.put(JacksonJsonBinaryType.class.getName() + ".objectMapper", objectMapper);
        };
    }
}

方案3：通过@Type参数指定自定义ObjectMapper #

在实体类的@Type注解中直接指定提供ObjectMapper的类：

@Entity
@TypeDef(name = "jsonb", typeClass = JsonBinaryType.class)
public class A {
    // 其他字段

    @Type(type = "jsonb", parameters = {
            @Parameter(name = JsonBinaryType.OBJECT_MAPPER, value = "com.example.config.CustomObjectMapper")
    })
    @Column(name = "jsonBody", columnDefinition = "jsonb")
    private SomeModel jsonBody;
}

对应的CustomObjectMapper类需要提供一个获取配置好的ObjectMapper的方法：

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;

public class CustomObjectMapper {
    public static ObjectMapper get() {
        ObjectMapper mapper = new ObjectMapper();
        mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
        return mapper;
    }
}

说明 #

@JsonIgnoreProperties(ignoreUnknown = true)无效的原因是：Hibernate的JsonBinaryType默认使用的ObjectMapper并未继承Spring Boot全局配置的序列化规则，需要单独为Hibernate的JSON类型配置忽略未知属性的特性。

内容的提问来源于stack exchange，提问作者Dezrhog