mappingMongoConverter.setMapKeyDotReplacement doesnt seem to have any effects - spring-data-mongodb

Question

I am trying to convert a custom object that contains a map containing dotted key string value using the latest 1.7.2 spring mongodb.
Setting a dot replacement doesnt seem to do the job. Here's my code :
class FakeUser {
Map<String, String> map = new LinkedHashMap<>();
void addValue(String key, String value) {
this.map.put(key, value);
}
}
FakeUser fakeUser = new FakeUser();
fakeUser.addValue("test.dot.for.key", "test.dot.for.value");
this.mappingMongoConverter.setMapKeyDotReplacement(":");
Object convertedObject = this.mappingMongoConverter.convertToMongoType(fakeUser);
System.out.println("convertedObject: " + convertedObject.getClass() + ":" + convertedObject);
And the output:
convertedObject: class com.mongodb.BasicDBObject:{ "map" : { "test.dot.for.key" : "test.dot.for.value"}}
And i also tried:
class FakeUser {
Map<String, String> map = new LinkedHashMap<>();
void addValue(String key, String value) {
this.map.put(key, value);
}
}
FakeUser fakeUser = new FakeUser();
fakeUser.addValue("test.dot.for.key", "test.dot.for.value");
this.mappingMongoConverter.setMapKeyDotReplacement(":");
BasicDBObject dbo = new BasicDBObject();
this.mappingMongoConverter.write(fakeUser, dbo);
System.out.println("dbo: " + ":" + dbo.toMap());
And with the output of dbo: :{_class=app.security.MyClass$1FakeUser, map={ "test.dot.for.key" : "test.dot.for.value"}}
I was expecting "test.dot.for.key" to become "test:dot:for:key", so what did i do wrong ?

Answer 1

You need make adjustments to the converter in your SpringMongoDBConfig (which should extend AbstractMongoConfiguration) config files, rather than in the class you're trying to serialize/deserialze. If you're using annotation driven settings, you can use a custom bean to set the converter like so:
#Bean
#Override
public MappingMongoConverter mappingMongoConverter() throws Exception
{
DbRefResolver dbRefResolver = new DefaultDbRefResolver(mongoDbFactory());
MappingMongoConverter converter = new MappingMongoConverter(dbRefResolver, mongoMappingContext());
converter.setCustomConversions(customConversions());
//mongo won't accept key values with dots(.) in them, so configure it to store them as :
converter.setMapKeyDotReplacement("\\:");
return converter;
}
Once the converter is setup, it will handle both serialization and deserialization for you automagically.
If you really want to do the conversion in-line (not recommended), you can just use a string replace function to re-write the string like so:
class FakeUser
{
Map<String, String> map = new LinkedHashMap<>();
void addValue(String key, String value) {
key = key.replace(".",":");
this.map.put(key, value);
}
}
Although, if you do it inline you'll likely have issues deserializing when you get it back out of mongo.