Jackson 使用 mixins 序列化具有动态不同名称的属性

2022-01-13 00:00:00 nosql java jackson mixins

我使用不同的 NoSQL 数据库，根据数据库，我需要将id"命名为不同的.因此，例如在 OrientDB 中，id 被命名为@rid"

I use different NoSQL databases and depending on the database I need to name the "id" different. So for example in OrientDB the id is named "@rid"

@JsonProperty("@rid")
private String id;

对于 MongoDB，id 被命名为_id"

And for MongoDB the id is named "_id"

@JsonProperty("@_id")
private String id;

我不知道现代数据库开发人员有什么问题，而不仅仅是将 id 字段命名为id"^^.但现在我有一个问题.如何动态序列化/反序列化 id 字段，在某些情况下为@rid"，在另一种情况下为_id"?

I do not know what is wrong with the modern DB developers not just naming the id field "id" ^^. But now I have a problem. How can I dynamically serialize/deserialize the id field in some case as "@rid" and in another case as "_id"?

根据 rmullers 的建议，我尝试使用 mixins.所以我有例如:

Based on rmullers suggestion I have tried to use mixins. So I have for example:

public interface IdMixins {
}

public interface MongoIdMixIn extends IdMixins {
    @JsonProperty("_id") String getId();
    @JsonProperty("_id") void setId(String id);
}

public interface OrientIdMixIn extends IdMixins{
    @JsonProperty("@rid") String getId();
    @JsonProperty("@rid") void setId(String id);
}

IdMixins 是一个完全空的接口，仅用于更好地控制哪些接口可以传递给映射器.

Where IdMixins is a completly empty interface just used to get more controll which interfaces can be passet to the mapper.

然后有一个类:

@JsonTypeInfo(use=JsonTypeInfo.Id.CLASS, include=JsonTypeInfo.As.PROPERTY, property="@javaClass")
public abstract class AbstractBean implements Serializable {
    private static final long serialVersionUID = -1286900676713424199L;

    // @JsonProperty("@rid")
    private String id;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }
}

但是当我运行这个简单的测试时，输出仍然是id":

But when I run this simple test, the output is still "id":

public class MixinTest {
    public static void main(String[] args) throws JsonProcessingException {
        Foo f = new Foo();
        f.setId("123");
        f.setBar("lala");

        ObjectMapper mapper = new ObjectMapper();

        ObjectMapper m2 = mapper.copy();
        m2.addMixInAnnotations(AbstractBean.class, MongoIdMixIn.class);
        System.out.println(m2.writeValueAsString(f));

        ObjectMapper m3 = mapper.copy();
        m3.addMixInAnnotations(AbstractBean.class, OrientIdMixIn.class);
        System.out.println(m3.writeValueAsString(f));

    }

    public static class Foo extends AbstractBean {
        private String bar;

        public String getBar() {
            return bar;
        }

        public void setBar(String bar) {
            this.bar = bar;
        }
    }
}

输出:

{"@javaClass":"test.MixinTest$Foo","id":"123","bar":"lala","@class":"Foo"}{"@javaClass":"test.MixinTest$Foo","id":"123","bar":"lala","@class":"Foo"}

{"@javaClass":"test.MixinTest$Foo","id":"123","bar":"lala","@class":"Foo"} {"@javaClass":"test.MixinTest$Foo","id":"123","bar":"lala","@class":"Foo"}

推荐答案

你试过使用 http://wiki.fastxml.com/JacksonMixInAnnotations?然后，您可以使用具有不同 @JsonProperty 配置的 OrientDbMixin 和 MongoDbMixin.

Have you tried using http://wiki.fasterxml.com/JacksonMixInAnnotations? Then you can use an OrientDbMixin and a MongoDbMixin with different @JsonProperty configuration.

更新:工作示例

public final class JacksonTest {

    static final class ExampleBean {

        private String id;
        private String bar;

        @JsonProperty("donotwanttoseethis")
        public String getId() {
            return id;
        }

        public void setId(String id) {
            this.id = id;
        }

        public String getBar() {
            return bar;
        }

        public void setBar(String bar) {
            this.bar = bar;
        }

    }

    public interface MongoIdMixIn {

        @JsonProperty("_id") String getId();

    }

    public interface OrientIdMixIn {

        @JsonProperty("@rid") String getId();

    }

    private final static Logger LOG = LoggerFactory.getLogger();

    public static void main(String[] args) throws JsonProcessingException {
        ExampleBean bean = new ExampleBean();
        bean.setId("1234");
        bean.setBar("lala");

        ObjectMapper m2 = new ObjectMapper();
        m2.addMixInAnnotations(ExampleBean.class, MongoIdMixIn.class);
        LOG.info(m2.writeValueAsString(bean));

        ObjectMapper m3 = new ObjectMapper();
        m3.addMixInAnnotations(ExampleBean.class, OrientIdMixIn.class);
        LOG.info(m3.writeValueAsString(bean));
    }

}

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