用数组反序列化json [英] deserializing json with arrays

问题描述

我使用jackson反序列化一些Json。我正在阅读一个大型的json文档并拔出块并告诉jackson将该块取出并将其反序列化为我在java中创建的对象（实际上有几个对象，因为有嵌套数组）以匹配json。

im using jackson to deserialize some Json. I am reading through a large json document and pulling out blocks and telling jackson to take that block and deserialize it to an object that I created (Actually several objects as there are nested arrays) in java to match the json.

用于反序列化的代码是

fooObject newFoo = mapper.readValue(newNode,fooObject.class);

问题是块中有一个值，有时是哈希值，如

The problem is there is a value in the block that is sometimes a hash such as

addWidgetStrategy={"get":2,"spend":6,"textLabel":"bikes"}

有时数组

addWidgetStrategy=[{"get":1.5,"spend":3,"textLabel":"thursday"},{"get":3,"spend":5,"textLabel":"tuesday"}]

所以在fooObject中我需要处理addWidgetStrategy，它有自己的对象。如果在fooObject中我放了

So in fooObject I need to deal with addWidgetStrategy which has its own object. If in fooObject I put

public addWidgetStrategy addWidgetStrategy;

以上工作直到它试图反序列化数组

The above works until it tried to deserialize an array

如果我把

public List<addWidgetStrategy>  addWidgetStrategy;

它仅适用于数组，只需单个哈希就会爆炸

it works just for arrays and blows up when its just a single hash

如何解析相同的Json元素addWidgetStrategy，无论它是数组还是单个哈希？

How can I parse that same Json element addWidgetStrategy regardless if its an array or a single hash?

推荐答案

对于数组，它应该是：

   fooObject[] newFoo = mapper.readValue(newNode,fooObject[].class);

你可以这样读：

   JsonNode jsonNode = mapper.readTree(json);
   if (jsonNode.isArray()) {
       fooObject[] newFoo = mapper.readValue(jsonNode,fooObject[].class);
       ...
   } else {
       fooObject newFoo = mapper.readValue(jsonNode,fooObject.class);  
       ....
   }

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