On Jul 10, 2013, at 20:01 , Jiaan Zeng <l.alle...@gmail.com> wrote:
> By reset I mean that variable is 0 every time when onEvent() is > called. Sorry for the confusion. From the wordcount point of view, it > is correct because the "int wordCounter;" is incremented to 1 in > onEvent(). I don't understand when and where the variable is reset to > 0. that variable initially has a 0 value when S4 creates a new PE instance in order to process a previously unseen key. Matthieu > > > On Wed, Jul 10, 2013 at 12:04 PM, Matthieu Morel <mmo...@apache.org> wrote: >> >> On Jul 10, 2013, at 17:30 , Jiaan Zeng <l.alle...@gmail.com> wrote: >> >>> Hi, >>> >>> I wonder how to maintain state in ProcessElement. For example, >>> >>> s4-core/src/test/java/org/apache/s4/wordcount/WordCountPE.java >>> The variable "int wordCounter;" is used in onEvent() function and is >>> reset to zero after the onEvent() function finishes. This is >>> stateless. >> >> I don't see where that variable is reset to 0, can you point out the code? >> >>> >>> s4-core/src/test/java/org/apache/s4/wordcount/WordClassifierPE.java >>> The variables "private int counter;" and "TreeMap<String, Integer> >>> counts" are used in onEvent() function to keep total word count and >>> word count for each word. This is stateful. >>> >>> I am confused about such behavior of ProcessElement. How do I turn >>> on/off stateless if there is such option? >> >> You can keep state in instance variables. >> >> Regards, >> >> Matthieu >> >>> >>> Thanks in advance. >>> >>> -- >>> Regards, >>> Jiaan >> > > > > -- > Regards, > Jiaan
