Demo.java

    MongoTemplate mongo = ...;

    List<Converter> converters = new ArrayList<Converter>();
    converters.add(new Converter<DBObject, Participant>() {
      public Participant convert(DBObject s) {
        throw new UnsupportedOperationException("Not supported yet 1.");
      }
    });
    
    converters.add(new Converter<Participant, DBObject>() {
      public DBObject convert(Participant s) {
        throw new UnsupportedOperationException("Not supported yet 2.");
      }
    });

    
    CustomConversions cc = new CustomConversions(converters);
    
    MappingMongoConverter mmc = (MappingMongoConverter)mongo.getConverter();
    mmc.setCustomConversions(cc);
    mmc.afterPropertiesSet()