MongoDB No converter found capable of converting from type [java.lang.String] to type [java.time.LocalDateTime]

Question

MongoDB, Spring Data, findAll() method error:

No converter found capable of converting from type [java.lang.String] to type [java.time.LocalDateTime]

public class EntityName {
    @Id
    private String id;
    private Map<LocalDateTime, Integer> statistic;
}

I am able to save entity, but not able to load it. Any quick fixes?

Solution

This solved the problem:

@Configuration
public class MongoConfiguration extends AbstractMongoConfiguration {

    @Value("${spring.data.mongodb.database:test}")
    private String database;

    @Value("${spring.data.mongodb.host:localhost}:${spring.data.mongodb.port:27017}")
    private String host;

    @Autowired
    private MappingMongoConverter mongoConverter;

    // Converts . into a mongo friendly char
    @PostConstruct
    public void setUpMongoEscapeCharacterConversion() {
        mongoConverter.setMapKeyDotReplacement("_");
    }

    @Override
    protected String getDatabaseName() {
        return database;
    }

    @Override
    public Mongo mongo() throws Exception {
        return new MongoClient(host);
    }

    @Bean
    @Override
    public CustomConversions customConversions() {
        List<Converter<?, ?>> converterList = new ArrayList<Converter<?, ?>>();
        converterList.add(new MongoLocalDateTimeFromStringConverter());
        return new CustomConversions(converterList);
    }

    private static final class MongoLocalDateTimeFromStringConverter implements Converter<String, LocalDateTime> {
        @Override
        public LocalDateTime convert(String source) {
            return source == null ? null : LocalDateTime.parse(source);
        }
    }
}