Question

我有以下课程：

public class Some implements Map<String, Object>{
    private Map<String, Object> innerMap;
    //implementation that can only set innerMap in constructor and cannot add or remove values
}

问题是我无法正确地在杰克逊中反序列化。如果我在没有默认输入的情况下序列化，那就没关系，因为它被序列化为{“one”：“two”}并且正确反序列化（我必须用

实现反序列化器）

return new Some(jp.readValueAs(new TypeReference<HashMap<String,Object>>(){}));

当我使用默认打字时，会将其序列化为

["com.class.Some",{"one":"two"}]

但反序列化正在抛出

com.fasterxml.jackson.databind.JsonMappingException: Unexpected token (START_OBJECT), expected START_ARRAY: need JSON Array to contain As.WRAPPER_ARRAY type information for class java.util.HashMap

有什么想法吗？

Answer 1

使用let parametersForFriends = ["fields": "name,id"] let graphRequestForFriends = FBSDKGraphRequest(graphPath: "me/friends", parameters: parametersForFriends)注释您的构造函数：

@JsonCreator

Answer 2

这就是我需要的 - 自定义反序列化器：

public class SomeDeserializer extends JsonDeserializer<Some> {

    @Override
    public Object deserializeWithType(JsonParser jsonParser, DeserializationContext ctxt, TypeDeserializer typeDeserializer) throws IOException {
        return typeDeserializer.deserializeTypedFromObject(jsonParser, ctxt);
    }

    @SuppressWarnings("unchecked")
    @Override
    public Some deserialize(JsonParser jp, DeserializationContext ctxt)
            throws IOException {
        JsonDeserializer<Object> deserializer = ctxt.findRootValueDeserializer(
                ctxt.getTypeFactory().constructMapType(Map.class, String.class, Object.class));

        return new Some((Map) deserializer.deserialize(jp, ctxt, new HashMap<>()));
    }
}

杰克逊 - Map <string，object =“”>实现的序列化

2 个答案: