Using Jackson to deserialise an array of object

0 votes

For a single object I would do this:

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

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


Now for an array I want to do this:

//json input
[{
    "id" : "junk",
    "stuff" : "bread"
},
{
    "id" : "healthy",
    "stuff" : "eggs"
}]

//Java
List<MyClass> entries = ?


Can anyone help me to find out the missing command?

Sep 26, 2018 in Java by Daisy
• 8,120 points
4,894 views

1 answer to this question.

0 votes

First create a mapper :

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

As Array:

MyClass[] myObjects = mapper.readValue(json, MyClass[].class);
As List:
List<MyClass> myObjects = mapper.readValue(jsonInput, new TypeReference<List<MyClass>>(){});
Another way to specify the List type:
List<MyClass> myObjects = mapper.readValue(jsonInput, mapper.getTypeFactory().constructCollectionType(List.class, MyClass.class));
answered Sep 26, 2018 by Sushmita
• 6,910 points

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