MongoDB-Escape dots '.' in map key]

My exception:

org.springframework.data.mapping.MappingException: Map key VAT Registration No. contains dots but no replacement was configured! Make sure map keys don't contain dots in the first place or configure an appropriate replacement!

Field with a dot at the end: VAT Registration No.

This didn't work for me:

mongoConverter.setMapKeyDotReplacement(".");
mongoConverter.setMapKeyDotReplacement("_"); //this broke enum values for example VALUE_1 -> VALUE.1

This works for me:

mongoConverter.setMapKeyDotReplacement("-DOT")

Complete class:

@Configuration
public class MongoConfiguration {

    @Bean
    public MappingMongoConverter mongoConverter(MongoDbFactory mongoFactory, MongoMappingContext mongoMappingContext) {
        DbRefResolver dbRefResolver = new DefaultDbRefResolver(mongoFactory);
        MappingMongoConverter mongoConverter = new MappingMongoConverter(dbRefResolver, mongoMappingContext);
        mongoConverter.setMapKeyDotReplacement("-DOT");
        return mongoConverter;
    }
}

When using Spring Data MongoDB you get an instance of: org.springframework.data.mongodb.core.convert.MappingMongoConverter that has mapKeyDotReplacement set to null by default - that is why you are getting an exception.

You need to either create your own instance of org.springframework.data.mongodb.core.convert.MappingMongoConverter or just modify existing instance using its provider setter method:

/**
 * Configure the characters dots potentially contained in a {@link Map} shall be replaced with. By default we don't do
 * any translation but rather reject a {@link Map} with keys containing dots causing the conversion for the entire
 * object to fail. If further customization of the translation is needed, have a look at
 * {@link #potentiallyEscapeMapKey(String)} as well as {@link #potentiallyUnescapeMapKey(String)}.
 * 
 * @param mapKeyDotReplacement the mapKeyDotReplacement to set
 */
public void setMapKeyDotReplacement(String mapKeyDotReplacement) {
    this.mapKeyDotReplacement = mapKeyDotReplacement;
}

In MongoDB, dot is always treated as a special character so avoiding it will most likely save you some other headache in the future.

EDIT: To override default MappingMongoConverter add the following bean declaration:

  @Bean
  public MappingMongoConverter mongoConverter(MongoDbFactory mongoFactory) throws Exception {
    DbRefResolver dbRefResolver = new DefaultDbRefResolver(mongoFactory);
    MappingMongoConverter mongoConverter = new MappingMongoConverter(dbRefResolver, mongoMappingContext);
    mongoConverter.setMapKeyDotReplacement(".");

    return mongoConverter;
  }