序列化固定大小的映射到CBOR [英] Serialize fixed size Map to CBOR

问题描述

我有以下JSON:

[
  {
    2: {
      "c": true
    }
  },
  {
    3: {
      "p": 10
    }
  }
]

我想转换为CBOR格式. 根据cbor.me，我有以下输出:

That I would like to convert to CBOR format. Accordingly to cbor.me I have the following output:

82A102A16163F5A103A161700A

82A102A16163F5A103A161700A

但是，当使用Jackson Binary CBOR串行器时，我有以下输出:

But, when using Jackson Binary CBOR Serializer, I have the following output:

82BF02BF6163F5FFFFBF03BF61700AFFFF

82BF02BF6163F5FFFFBF03BF61700AFFFF

这没错，但没有进行优化...我实际上增加了4个不必要的字节.

Which is not wrong, but not optimized... I have an extra 4 unnecessary bytes added to what it can really be.

然后我尝试手动序列化JSON，但结果相同:

I've then tried to manually serialize the JSON but same result:

@Override
public void serialize(Request value, JsonGenerator jgen, SerializerProvider provider)
        throws IOException, JsonProcessingException {
    jgen.writeStartArray(value.getDataList().size());
    for (Data data : value.getDataList()) {
        jgen.writeStartObject(new Map[1]);
        jgen.writeFieldId(data.getItem());
        jgen.writeStartObject();
        if (data.getObject().getC() != null) {
            jgen.writeBooleanField("c", data.getObject().getC());
        }
        if (data.getObject().getP() != null) {
            jgen.writeNumberField("p", data.getObject().getP());
        }
        jgen.writeEndObject();
        jgen.writeEndObject();
    }
    jgen.writeEndArray();
}

这是Jackson Binary格式库的错误，还是我缺少ObjectMapper的某些配置属性?

Is this a bug with Jackson Binary format library or am I missing some configuration properties from the ObjectMapper?

编辑:这似乎是一个已知问题:

EDIT: This seems to be a known issue: https://github.com/FasterXML/jackson-dataformats-binary/issues/3

推荐答案

使用版本2.9.4可以在CBORGenerator类中使用以下方法:public final void writeStartObject(int elementsToWrite)

By using version 2.9.4 the following method is available in the CBORGenerator class: public final void writeStartObject(int elementsToWrite)

@Override
public void serialize(Request value, JsonGenerator jgen, SerializerProvider provider)
        throws IOException, JsonProcessingException {
    jgen.writeStartArray(value.getDataList().size());
    for (Data data : value.getDataList()) {
        ((CBORGenerator) jgen).writeStartObject(1);
        jgen.writeFieldId(data.getItem());
        ((CBORGenerator) jgen).writeStartObject(1);
        if (data.getObject().getC() != null) {
            jgen.writeBooleanField("c", data.getObject().getC());
        }
        if (data.getObject().getP() != null) {
            jgen.writeNumberField("p", data.getObject().getP());
        }
        jgen.writeEndObject();
        jgen.writeEndObject();
    }
    jgen.writeEndArray();
}

我有以下输出:

82A102A16163F5A103A161700A

82A102A16163F5A103A161700A

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