https://stackoverflow.com/q/46767604/1032167

Parse JSON to deeply nested generic with jackson

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.type.TypeFactory;

import java.io.IOException;
import java.util.List;

/**
 * Created by varren on 16.10.17.
 */
public class Main15 {

    private static String json = "{\n" +
            "    \"Level1\": {\n" +
            "        \"Level2\": {\n" +
            "            \"Level3\": {\n" +
            "                \"genericObject\": [\n" +
            "                    { \n" +
            "                      \"attribute1\": \"a\", \n" +
            "                      \"attribute2\": \"b\"\n" +
            "                    },\n" +
            "                    { \n" +
            "                      \"attribute1\": \"c\", \n" +
            "                      \"attribute2\": \"d\"\n" +
            "                    } \n" +
            "                ]\n" +
            "            }\n" +
            "        }\n" +
            "    }\n" +
            "}";

    private static String json2= "{\n" +
            "    \"Level1\": {\n" +
            "        \"Level2\": {\n" +
            "            \"Level3\": {\n" +
            "                \"genericObject\": [\"attribute1\",\"attribute2\",\"attribute3\",\"attribute4\"]\n" +
            "            }\n" +
            "        }\n" +
            "    }\n" +
            "}";
    public static void main(String[] args) throws IOException {

        
        test(SomeObject.class, json);
        test(String.class, json2);

    }

    private static void test(Class<?> c, String json) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        // because we dont have object above Level1 so lvl1 is a field of root object
        mapper.enable(DeserializationFeature.UNWRAP_ROOT_VALUE);

        JavaType javaType = TypeFactory.defaultInstance().constructParametricType(Level1.class, c);
        System.out.println((Level1)mapper.readValue(json, javaType));
    }
    static class Level1<T> {
        @JsonProperty("Level2")
        public Level2<T> l2;

        @Override
        public String toString() {
            return "Level1{" +
                    "l2=" + l2 +
                    '}';
        }
    }

    static class Level2<T> {
        @JsonProperty("Level3")
        public Level3<T> l3;

        @Override
        public String toString() {
            return "Level2{" +
                    "l3=" + l3 +
                    '}';
        }
    }

    static class Level3<T> {
        @JsonProperty("genericObject")
        public List<T> objectsList;

        @Override
        public String toString() {
            return "Level3{" +
                    "objectsList=" + objectsList +
                    '}';
        }
    }

    static class SomeObject{
        public String attribute1;
        public String attribute2;

        @Override
        public String toString() {
            return "SomeObject{" +
                    "attribute1='" + attribute1 + '\'' +
                    ", attribute2='" + attribute2 + '\'' +
                    '}';
        }
    }
}