Im trying to Deserialize a hashmap using jackson. My data structure is

public class FilterDto {

    private Map<String, List<String>> sectorFilter;

    public FilterDto() {}

    public Map<String, List<String>> getSectorFilter() {
        return sectorFilter;
    }

    public void setSectorFilter(Map<String, List<String>> sectorFilter) {
        this.sectorFilter = sectorFilter;
    }

}

My request body is

{
  "sectorFilter": [
    {
      "ab": [
        "abc",
        "cde"
      ]
    }
  ]
}

When i tried to deserialize this i got

Cannot deserialize instance of `java.util.Map<java.lang.String,java.util.List<java.lang.String>>` out of START_ARRAY token

So i tried using a custom deserialzer to see whether it would work. I created a custom deerialzer like below

public class FilterDeserializer  extends StdDeserializer<Map<String,List<String>>> {


    public FilterDeserializer(StdDeserializer<?> src) {
        super(src);
    }

    @Override
    public Map<String,List<String>> deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException, JsonProcessingException {
        
    }
}

and added it to my dto

@JsonDeserialize(using = FilterDeserializer.class)
private Map<String, List<String>> sectorFilter;

but now im getting

No qualifying bean of type 'com.fasterxml.jackson.databind.deser.std.StdDeserializer<?>' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}

any idea how can i get this work ? Thanks

CodePudding user response：

sectorFilter, as you’ve shown, isn’t a map, it’s an array of JSON objects. Try to deserialize as List<Map<String, List<String>>>. Of course, you can also create classes mimicking that structure if you want.