如何使用Jackson对一系列对象进行反序列化 [英] How to use Jackson to deserialise an array of objects

问题描述

Jackson数据绑定文档表明Jackson支持反序列化所有支持类型的数组，但我可以找出确切的语法。

The Jackson data binding documentation indicates that Jackson supports deserialising "Arrays of all supported types" but I can't figure out the exact syntax for this.

对于单个对象，我会这样做：

For a single object I would do this:

//json input
{
    "id" : "junk",
    "stuff" : "things"
}

//Java
MyClass instance = objectMapper.readValue(json, MyClass.class);

现在对于一个数组我想这样做：

Now for an array I want to do this:

//json input
[{
    "id" : "junk",
    "stuff" : "things"
},
{
    "id" : "spam",
    "stuff" : "eggs"
}]

//Java
List<MyClass> entries = ?

任何人都知道是否有魔法缺失命令？如果没有那么解决方案是什么？

Anyone know if there is a magic missing command? If not then what is the solution?

推荐答案

首先创建一个映射器：

import com.fasterxml.jackson.databind.ObjectMapper;// in play 2.3
ObjectMapper mapper = new ObjectMapper();

As Array：

MyClass[] myObjects = mapper.readValue(json, MyClass[].class);

作为清单：

List<MyClass> myObjects = mapper.readValue(jsonInput, new TypeReference<List<MyClass>>(){});

指定列表类型的另一种方法：

Another way to specify the List type:

List<MyClass> myObjects = mapper.readValue(jsonInput, mapper.getTypeFactory().constructCollectionType(List.class, MyClass.class));

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