Spring-Data Mongo doesn't use converters while serializing key Objects from Map Properties [DATAMONGO-449]

[spring-projects-issues]

Alexander Bätz opened DATAMONGO-449 and commented

While serializing properties/objects of the type Map the keys are serialized by using the toString() method.
This fails for complex classes even when there is a Converter<MyComplexClass, String> for it.

During deserialization the string representing the id is deserialized by using the converters, so a workaround is to call the proper converter in the toString() method. But this only works for classes that can be converted from/into strings

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Affects: 1.0.1

Issue Links:

• DATAMONGO-242 Allow using complex types as Map keys
  ("duplicates")

[spring-projects-issues]

Alexander Bätz commented

The Class serializing maps is the MappingMongoConverter

[spring-projects-issues]

Oliver Drotbohm commented

You've pretty much stumbled over what we already capture in DATAMONGO-242. I'll close this one as duplicate, please follow the other ticket for progress. The summary is that MongoDB only supports String keys by default and mapping maps with complex keys into a structure like this:

{ myMap : [ { key : { … complex key … },
              value : { … value … }]}

would seriously influence you write queries, how your indexes work (or not work as you cannot really index particular keys anymore) etc., which is not really obvious from the domain model