Refactoring: use namedJdbcTemplate bean instead of internal new object

[strehle]

Allow to mock the objects in future

e.g. if jdbcTemplate is a mock then sometimes such pattern new NamedParameterJdbcTemplate(jdbcTemplate) causes a not testable code block like in JdbcScimUserProvisioning

For jdbcTemplate we create one instance and re-use it, therefore if NamedParameterJdbcTemplate is used in several beans, then we should do the same

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/187536573

The labels on this github issue will be updated when the story is started.

[peterhaochen47]

Allow to mock the objects in future
e.g. if jdbcTemplate is a mock then sometimes such pattern new NamedParameterJdbcTemplate(jdbcTemplate) causes a not testable code block like in JdbcScimUserProvisioning

Hi! I don't think I understand this point. Could you elaborate? What code block is not testable under JdbcTemplate and how does NamedParameterJdbcTemplate solve that problem?

It looks like the main advantage of NamedParameterJdbcTemplate is that you could perform param substitution on the SQL string in a stricter manner (but I don't see this feature being used in this PR?).

[strehle]

Allow to mock the objects in future
e.g. if jdbcTemplate is a mock then sometimes such pattern new NamedParameterJdbcTemplate(jdbcTemplate) causes a not testable code block like in JdbcScimUserProvisioning

Hi! I don't think I understand this point. Could you elaborate? What code block is not testable under JdbcTemplate and how does NamedParameterJdbcTemplate solve that problem?

It looks like the main advantage of NamedParameterJdbcTemplate is that you could perform param substitution on the SQL string in a stricter manner (but I don't see this feature being used in this PR?).

The change is, that classes which use this can now be mocked, as done with #2863

Another reason why I wanted this refactoring is that I was wondering for a while, why we create a datasource and jdbcTemplate in a single place -> data-source.xml and re-use this reference in all needed places but the enhance jdbc class NamedParameterJdbcTemplate is always newly generated with each bean creating, see
https://github.com/search?q=repo%3Acloudfoundry%2Fuaa+%22new+NamedParameterJdbcTemplate%22&type=code

I think we will re-use NamedParameterJdbcTemplate more often therefore good to use it in same way we do with underlying jdbcTemplate/datasource