Improve framework for custom mapping couchbase converter.

[mikereiche]

1. change examples in Config to show creating repository mappings using
   existing MappingCouchbaseConverter (which have customConversions /
   BeanNames.COUCHBASE_CUSTOM_CONVERSIONS and applicationContext)
   instead of creating their own and then adding the customConversion and
   applicationContext.

2. remove unused members fro StringBasedN1qlQueryParser

Closes #1141.

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[daschl]

+2, just one minor comment that can slightly improve user experience. but feel free to merge

[daschl]

should we throw an exception if the mappingContext is not instanceof CouchbaseMappingContext? So it will be descriptive

[mp911de]

Actually, the converter should be ApplicationContextAware so that the bean container injects the context. You could skip that line and stop exposing the context from the mapping context for a clean implementation.

[mikereiche]

Yes. This shouldn't be done here. It's similar to afterPropertiesSet() call, in that it should normally be done by the Bean container. And if the object is created outside the bean container, then the caller has to take care of the initialization that the bean container would normally do. So I'll remove this and not expose the applicationContext of the mapping context.

[mp911de]

Please refrain from calling lifecycle methods in setters. Calling afterPropertiesSet is a responsibility of the bean container.

[mikereiche]

I can fix that by instead calling conversions.registerConvertersIn(conversionService) directly here.

The underlying issue is that
(a) setCustomConversions() doesn't do everything needed to setCustomConversions(). It only does this.conversions = conversions and that isn't sufficient. It is also necessary to conversions.registerConvertersIn(conversionService) - otherwise the conversionService is not aware of the conversions. I made the call to afterPropertiesSet() in the event that in the future additional actions were added.
(b) the mapping converter was created outside the Bean container - in #1141 - although that should be unnecessary by creating the template for configureRepositoryOperationsMapping using the converter (MappingCouchbaseConverter) (baseMapping.getDefault().getConverter()) .

Somewhat related - Intellij complains when an @bean is called directly, but sometimes it is necessary - when the value of an @bean method is being used in another public @bean method, and the signature of that public @bean method cannot (should not?) be changed. On the other hand - if there was a guarantee that no applications were calling the @bean method directly, then changing the signature should not be a problem. This issue exists in three bean methods in AbstractCouchbaseConfiguration. The "solution" has been to make @bean method call - the problem with this is that the result of that call is not the actual @bean, it's a different object. (I suppose that if the result object was cached and used on subsequent calls, then it could be the same object).

couchbaseObjectMapper() is an @bean method, it is now required by the couchbaseClusterEnvironment() @bean, but was not/is not a method argument. This had been "fixed" previously by having an @Autowired CouchbaseObjectMapper in the class - but that resulted in a circular reference when @componentscan was used.

	@Bean(destroyMethod = "shutdown")
	public ClusterEnvironment couchbaseClusterEnvironment() 
	   ... 
	   builder.jsonSerializer(JacksonJsonSerializer.create(couchbaseObjectMapper()));

This couchbaseTemplate() method was previously the @bean, but has been superseded with a method with an additional argument.

	public CouchbaseTemplate couchbaseTemplate(CouchbaseClientFactory couchbaseClientFactory,
			MappingCouchbaseConverter mappingCouchbaseConverter) {
		return couchbaseTemplate(couchbaseClientFactory, mappingCouchbaseConverter, new JacksonTranslationService());
	}

[mp911de]

setCustomConversions() doesn't do everything needed to setCustomConversions(). It only doe

That's by intent. The bean configuration phase consists from calling all setters first and then initialize the bean with afterPropertiesSet. That being said, calling registerConvertersIn(…) in the setter isn't better.

the mapping converter was created outside the Bean container

It is then the responsibility of the creator to initialize that bean.

[mikereiche]

ok. I'll just remove the call and not replace it with anything.