How do I use Jackson to deserialize an array of objects? Recommended | Java Debug Notes

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** How to use Jackson to deserialize an array of objects? 支那

The documentation on Jackson data binding states that Jackson supports deseriavenues “all support for arrays” but I can’t figure out the exact syntax for this.

For a single object, I can do this:

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

//Java
MyClass instance = objectMapper.readValue(json, MyClass.class);
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Now, for arrays, I want to do this:

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

//Java
List<MyClass> entries = ?
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Does anyone know if there’s a magical order? If not, what is the solution?

Answer:

$\color{purple} a lot of knowledge points, really need to write out just can master!! {~}$

First create a mapper:

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

As an array:

MyClass[] myObjects = mapper.readValue(json, MyClass[].class);
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As a list:

List<MyClass> myObjects = mapper.readValue(jsonInput, new TypeReference<List<MyClass>>(){});
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Another way to specify a list type:

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

From Eugene Tskhovrebov

List<MyClass> myObjects = Arrays.asList(mapper.readValue(json, MyClass[].class))
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This solution seems to be the best for me.

The article translated from am2dgbqfb6mk75jcyanzabc67y ac4c6men2g7xr2a – stackoverflow – com. Translate. Goog/questions / 6…

Author’s suggestion: Used Jackson, have a lookdoc:Arrays.asList(mapper.readValue(json, MyClass[].class))

For an extension: juejin.cn/post/696217…

Gson can support three layers of nesting, Jackson community is active, Fastjson is very popular in China, but there are shortcomings, I see ali cloud is not using Fastjson to parse JSON

The reason WHY I know ali cloud is not using Fastjson to parse JSON is because, I docking nail API document, in the source code does not appear fastjson figure, if you are interested, but PRIVATE message I want to source!

$\color{red} Welcome to my column StackOverFlow, I will filter the quality of the interview test!! {~}$

$\color{red} has the latest, elegant implementation, and I will also write my opinion on this question at the end of the article {~}$

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