CODEWITHSUNDEEP
javajackson
Kaniel Outis
Kaniel Outis

Reputation: 11

jackson deserialize string to a parameterized map

I have a json string in the following structure:

{   
    "1": { ... },
    "2": { ... },
    "3": { ... }
}

where 1, 2 and 3 are identifiers.

I want to deserialize this string and cast it to the following type - Map<Integer, List<MyCustomPojo>>

The thing is that each value { ... } has its own structure, but I need to parse them all and cast to a common structure - MyCustomPojo.

I can do it by implementing a custom deserializer:

public class CustomMapDeserializer extends JsonDeserializer<Map<Integer, List<MyCustomPojo>>> {

    @Override
    public Map<Integer, List<MyCustomPojo>> deserialize(JsonParser jsonParser, DeserializationContext context) throws IOException {
        JsonNode root = jsonParser.getCodec().readTree(jsonParser);

    // parse JsonNode and return  Map<Integer, List<MyCustomPojo>>      
}

Now I need to add this deserializer to a module and then register it with an object mapper.

SimpleModule module = new SimpleModule();
module.addDeserializer(Map.class, new CustomMapDeserializer()); // can’t specify type for map
objectMapper.registerModule(module);

The problem is that now it will be applied to all Map classes in my application. I want it to apply only to parameterized map - Map<Integer, List<MyCustomPojo>>.

Is it possible to do it?

Upvotes: 1

Views: 289

Answers (2)

adrien olivier
adrien olivier

Reputation: 125

Simplest solution should be to create a new class which inherit from Map and use it when you add deserializer

Upvotes: 1

Tyler
Tyler

Reputation: 203

The way you're thinking of isn't going to work, and might need to rewrite some of the code to apply ONLY to your parameterized map. I don't want to give any false info, sorry I can't provide a solution, but I hope this comment will help others to provide a solution for other abled coders.

Upvotes: 0

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