rest - JsonMappingException : Already had POJO for id

Question

尝试使用 @JsonIdentityInfo jackson 注释时出错。当我尝试反序列化对象时，出现以下异常:

Could not read JSON: Already had POJO for id (java.lang.Integer) [1] (through reference chain: eu.cobiz.web.domain.Site["operators"]->eu.yavix.web.domain.Account["image"]->eu.cobiz.web.domain.Image["@Image"]);nested exception is com.fasterxml.jackson.databind.JsonMappingException: Already had POJO for id (java.lang.Integer) [1] (through reference chain: eu.yavix.web.domain.Site["operators"]->eu.cobiz.web.domain.Account["image"]->eu.cobiz.web.domain.Image["@Image"])

我试图反序列化的 JSON 看起来像:

{
"@Site": 1,
"siteId": 1,
"name": "0",
"address": {
    "@Address": 2,
    "addressId": 4,
    "number": "22"
},
"operators": [
    {
        "accountId": 1,
        "email": "user982701361@yavix.eu",
        "image": {
            "@Image": 1,
            "imageId": 1,
            "uri": "http://icons.iconarchive.com/icons/deleket/purple-monsters/128/Alien-awake-icon.png"
        }
    },
    {
        "accountId": 2,
        "email": "user174967957@yavix.eu",
        "image": {
            "@Image": 2,
            "imageId": 2,
            "uri": "http://icons.iconarchive.com/icons/deleket/purple-monsters/128/Alien-awake-icon.png"
        }
    }
]
}

我的域对象注释为

@JsonIdentityInfo(generator = ObjectIdGenerators.IntSequenceGenerator.class, property = "@Image")

问题出现在@Id 注释上，因为如果我删除注释，问题就会消失(正如我为帐户所做的那样)，但据我所知，新功能对循环依赖很有用，这对我在其他情况下很有用。这两个图像之间不应该有冲突，因为它们是不同的对象。
我该如何解决这个问题或者是什么问题？

Answer 1

您应该使用 scope注释 id 时的参数。然后反序列化器将确保 id 在范围内是唯一的。

来自注释类型 JsonIdentityInfo :

Scope is used to define applicability of an Object Id: all ids must be unique within their scope; where scope is defined as combination of this value and generator type.

例如

@JsonIdentityInfo(generator=ObjectIdGenerators.IntSequenceGenerator.class,property="@id", scope = Account.class)