使用Jackson在Java中解析JSON的子集 [英] Parsing a subset of JSON in Java using Jackson
问题描述
鉴于Json,是否可以使用Jackson仅解析消息的一部分?
假设我感兴趣的数据埋藏在深层次的字段中,我根本不关心为每个类创建DTO类。
Given a Json, is it possible to use Jackson to only parse out a section of the message? Say that the data I'm interested in is buried in a deep hierarchy of fields and I simply do not care about creating DTO classes for each and every class.
鉴于一个非常简化的场景我想建模电话类而不知道它之前的结构:
Given a very simplified scenario I'd like to model the Telephone class without knowing anything about the structure before it:
...{
"firstName": "John",
"lastName" : "doe",
"age" : 26,
"address" : {
"streetAddress": "naist street",
"city" : "Nara",
"postalCode" : "630-0192"
},
"phoneNumbers": [
{
"type" : "iPhone",
"number": "0123-4567-8888"
},
{
"type" : "home",
"number": "0123-4567-8910"
}
]
}....
我正在考虑使用json-path和反序列化我感兴趣的部分。一些伪:
I'm thinking something in the terms of using json-path together with deserializing just the parts I'm interested of. Some pseudo:
List<Telephone> phoneNrs = parse(".my.deep.structure.persons.phoneNumbers", List<Telephone.class>);
推荐答案
ObjectMapper mapper = new ObjectMapper();
JsonNode json = mapper.readTree("... your JSON ...");
使用 JsonNode
对象,然后可以调用 get(my)。get(deep)。get(structure)
获取所需的节点。
Using the JsonNode
object you can then call get("my").get("deep").get("structure")
to get the node you want.
一旦你掌握了那个节点,只需简单调用 mapper.treeToValue(myDeepJsonNode,Telephone [] .class)
就可以得到你的数组电话
。您也可以使用 TypeReference
获取列表。
Once you got your hands on that node, a simple call to mapper.treeToValue(myDeepJsonNode, Telephone[].class)
will get you your array ofTelephone
. You can get a list using a TypeReference
as well.
要深入 JsonNode
你也可以使用 findValue
和 findPath
方法。
To get to your deep JsonNode
you can also use the findValue
and findPath
methods.
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