Fred Ji created SAMZA-1160:
------------------------------
Summary: Migrate MapConfig inherited Java classes to use
composition over inheritance
Key: SAMZA-1160
URL: https://issues.apache.org/jira/browse/SAMZA-1160
Project: Samza
Issue Type: Task
Reporter: Fred Ji
In Samza code, we have a lot of classes with the name "*Config" which inherits
from MapConfig but only intending to exposing the APIs for the specific
configuration.
For example, JavaStorageConfig, it currently extends MapConfig, but it only
intends to manage/fetch storeNames and store related configs, but not other
configs. With the inheritance, it does not have good encapsulation and it
allows the object JavaStorageConfig to call any public API from MapConfig as
well, for example, javaStorageConfig.get("yarn.resources.package.path"). With
it, it mixes up the business logic for different types of Config.
A proposal for addressing this is to do composition over inheritance, each type
of Config, for example, JavaStorageConfig can have a member variable config
which can leverage the interface of Config class (or the implementation of
MapConfig) but not exposing the APIs of Config further down.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
