[ https://issues.apache.org/jira/browse/IMPALA-7867?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Paul Rogers reassigned IMPALA-7867: ----------------------------------- Assignee: (was: Paul Rogers) > Expose collection interfaces, not implementations > ------------------------------------------------- > > Key: IMPALA-7867 > URL: https://issues.apache.org/jira/browse/IMPALA-7867 > Project: IMPALA > Issue Type: Improvement > Components: Frontend > Affects Versions: Impala 3.0 > Reporter: Paul Rogers > Priority: Minor > > When using Java collections, a common Java best practice is to expose the > collection interface, but hide the implementation choice. This pattern allows > us to start with a generic implementation (an {{ArrayList}}, say), but evolve > to a more specific implementation to achieve certain goals (a {{LinkedList}} > or {{ImmutableList}}, say.) > For whatever reason, the Impala FE code exposes {{ArrayList}}, {{HashMap}} > and other implementation choices as variable types and in method signatures. > This ticket tracks a gradual process of revising the declarations and > signatures to use the interfaces {{List}} instead of the implementation > {{ArrayList}}. > Also, the FE code appears to predate Java 7, so that declarations of lists > tend to be in one of two forms (with or without Guava): > {code:java} > foo1 = new ArrayList<Bar>(); > foo2 = Lists.newArrayList(); > {code} > Since Java 7, the preferred form is: > {code:java} > foo = new ArrayList<>(); > {code} -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org