streams-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (STREAMS-288) StreamsJacksonModule should not scan for DateTimeFormats by default
Date Tue, 17 Feb 2015 20:21:11 GMT

    [ https://issues.apache.org/jira/browse/STREAMS-288?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14324813#comment-14324813
] 

ASF GitHub Bot commented on STREAMS-288:
----------------------------------------

Github user steveblackmon commented on the pull request:

    https://github.com/apache/incubator-streams/pull/187#issuecomment-74744716
  
    So this is just a performance concern? I agree that creating a new Mapper inside of a
loop is obviously a bad idea.  That's why :
    
    public class StreamsJacksonMapper extends ObjectMapper {
    
        private static final StreamsJacksonMapper INSTANCE = new StreamsJacksonMapper();
    
        public static StreamsJacksonMapper getInstance(){    return INSTANCE;   }
    
    Get your mapper this way and only once and problem solved.
    
    I don't think the fact that bad implementations can get slow is a reason to make the default
behavior worse, to make a call that should only happen once per jvm a bit faster.



> StreamsJacksonModule should not scan for DateTimeFormats by default
> -------------------------------------------------------------------
>
>                 Key: STREAMS-288
>                 URL: https://issues.apache.org/jira/browse/STREAMS-288
>             Project: Streams
>          Issue Type: Bug
>            Reporter: Robert Douglas
>
> The StreamsJacksonModule's constructor is called all over the codebase and by default,
it uses Reflections to scan the classpath for valid DateTimeFormats.
> This is problematic because it will happen multiple times during a Stream's runtime,
considerably slowing down the execution.
> Instead, we should default to NOT scanning the classpath, but provide a constructor where
we can pass in a flag dictating whether or not we want to scan.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message