java - Using Jackson to deserialize into a Map

Question

I have a JSON object with two attributes: "key" which is a string, and "value" which can be deserialized into a Java bean.

{ "key": "foo", "value": "bar" }

The question is, given a list of such objects, can I deserialize it into a Map?

[{"key": "foo1", "value": "bar1"}, {"key": "foo2", "value": "bar2"}] -> Map<String, String>

Currently using Jackson-databind 2.1

Answer 1

You can easily convert above JSON to List<Map<String, String>>:

import java.util.List;
import java.util.Map;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.type.CollectionType;

public class JacksonProgram {

    public static void main(String[] args) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        CollectionType mapCollectionType = mapper.getTypeFactory().constructCollectionType(List.class, Map.class);
        List<Map<String, String>> result = mapper.readValue(json, mapCollectionType);
        System.out.println(result);
    }
}

Above program prints:

[{key=foo1, value=bar1}, {key=foo2, value=bar2}]