How use Custom Conversions Spring-data-elasticsearch

Question

I am using Elasticist 4.0.1. I have a field

@Field(type = FieldType.Nested, index = false, includeInParent = true)
private Map<String, Map<String, List<City>>> province = new HashMap<>();

According to the documentation, I did Custom Conversions.

public class ElasticConfig extends AbstractElasticsearchConfiguration {


@Bean
@Override
public RestHighLevelClient elasticsearchClient() {

    ClientConfiguration clientConfiguration
            = ClientConfiguration.builder()
            .connectedTo("0.0.0.0:9200")
            .build();

    return RestClients.create(clientConfiguration).rest();
}
@Bean
public ElasticsearchOperations elasticsearchTemplate() {
    return new ElasticsearchRestTemplate(elasticsearchClient());
}

@Bean
@Override
public ElasticsearchCustomConversions elasticsearchCustomConversions() {
    return new ElasticsearchCustomConversions(Arrays.asList(new ProvinceToMap(), new MapToProvince()));
}

@WritingConverter
static class ProvinceToMap implements Converter<Map<String, Map<String, ArrayList<City>>>, Map<String, Object>> {

    @Override
    public Map<String, Object> convert(Map<String, Map<String, ArrayList<City>>> userTaskEvents) {

        HashMap<String, Object> target = new HashMap<>();

        for(Map.Entry<String, Map<String, ArrayList<City>>> entry: userTaskEvents.entrySet()) {
            target.put(entry.getKey(), entry.getValue());

        }

        return target;
    }

}

@ReadingConverter
static class MapToProvince implements Converter<Map<String, Object>, Map<String, Map<String, ArrayList<City>>>> {

    @Override
    public Map<String, Map<String, ArrayList<City>>> convert(Map<String, Object> stringObjectMap) {
        ObjectMapper oMapper = new ObjectMapper();

        Map<String, Map<String, ArrayList<City>>> target = new HashMap<>();

        for(Map.Entry<String, Object> entry: stringObjectMap.entrySet()) {
            Map<String, ArrayList<Map<String, Object>>> event = oMapper.convertValue(entry.getValue(), Map.class);

            target.put(entry.getKey(), conv);
        }

        return target;
    }

When I execute this piece of code.

 for(Map.Entry<String, Map<String, ArrayList<City>>> entry: userTaskEvents.entrySet()) {
            target.put(entry.getKey(), entry.getValue());

            for (Map.Entry<String, ArrayList<City>> aaa: entry.getValue().entrySet()) {
                for (TestClass tt: aaa.getValue())
                    System.out.println(tt.getNameCity());
            }

        }

I get an error

java.lang.ClassCastException: java.util.HashMap cannot be cast to org.elasticsearch.example.model.City
at kz.elasticsearch.example.config.ElasticConfig$UserTaskEventToMap.convert(ElasticConfig.java:66) ~[classes/:na]
at kz.elasticsearch.example.config.ElasticConfig$UserTaskEventToMap.convert(ElasticConfig.java:54) ~[classes/:na]

...

Maybe I'm not doing it right. I noticed that when I receive data from elastic, the data is cast be as Map.

How to use the parts correctly 4.0.1. I've used Jackson before.

Answer 1

I brought this Map into a separate class.

public class SomeHardMap {

   private Map<String, Map<String, ArrayList<TestClass>>> hardMap = new HashMap<>();
   /// Getter and Setter
........

Elasticsearch field class

@Field(type = FieldType.Object) private SomeHardMap someHardMap = new SomeHardMap();

When the @ReadingConverter is done, the Province class is resolved as a Map. I was writing to do additional mapping. I didn't manage to do it beautifully

@WritingConverter static class UserTaskEventToMap implements Converter<SomeHardMap, Object> {

    @Override
    public Object convert(SomeHardMap userTaskEvents) {


        Object obj = userTaskEvents;
        return obj;
    }

}

@ReadingConverter static class MapToUserTaskEvent implements Converter<Object, SomeHardMap> {

    @SneakyThrows
    @Override
    public SomeHardMap convert(Object stringObjectMap) {

        Map<String, Map<String, Map<String, ArrayList<Map<String, String>>>>> mamamia = (Map)stringObjectMap;

        Map<String, Map<String, ArrayList<TestClass>>> hardMapV = new HashMap<>();

        for (Map.Entry<String, Map<String, Map<String, ArrayList<Map<String, String>>>>> entryObj: mamamia.entrySet()) {

            for (Map.Entry<String, Map<String, ArrayList<Map<String, String>>>> entryMapHight: entryObj.getValue().entrySet()) {

                Map<String, ArrayList<TestClass>> hard1 = new HashMap<>();

                for (Map.Entry<String, ArrayList<Map<String, String>>> entryNextLevel: entryMapHight.getValue().entrySet()) {

                    ArrayList<TestClass> list = new ArrayList<>();

                    entryNextLevel.getValue().forEach(f -> list.add(mapClass(f)));


                    hard1.put(entryNextLevel.getKey(), list);
                }

                hardMapV.put(entryMapHight.getKey(), hard1);
            }
        }

        SomeHardMap hardMap = new SomeHardMap();
        hardMap.setHardMap(hardMapV);
        return hardMap;
    }

    private TestClass mapClass(Map<String, String> f) {
        TestClass testClass = new TestClass();
        for(Map.Entry<String, String> entry: f.entrySet()) {

            if (entry.getKey().equals("workPlace"))
                testClass.setWorkPlace(entry.getValue());
            else if (entry.getKey().equals("city"))
                testClass.setCity(entry.getValue());
            else if(entry.getKey().equals("nameJob"))
                testClass.setNameJob(entry.getValue());
        }

        return testClass;
    }
}

If someone decided otherwise, you can share. If necessary, I publish a test project on the github