Re: Variable not initialized in the open() method of RichMapFunction

[Dong iL, Kim]

oops. stephan already answered.
sorry. T^T

On Sat, Jul 23, 2016 at 12:16 AM, Dong iL, Kim <kim.s...@gmail.com> wrote:

> is open method signature right? or typo?
>
> void open(Configuration parameters) throws Exception;
>
> On Sat, Jul 23, 2016 at 12:09 AM, Stephan Ewen <se...@apache.org> wrote:
>
>> I think you overrode the open method with the wrong signature. The right
>> signature would be "open(Configuration cfg) {...}". You probably overlooked
>> this because you missed the "@Override" annotation.
>>
>> On Fri, Jul 22, 2016 at 4:49 PM, Yassin Marzouki <yassmar...@gmail.com>
>> wrote:
>>
>>> Hi everyone,
>>>
>>> I want to convert a stream of json strings to POJOs using Jackson, so I
>>> did the following:
>>>
>>> .map(new RichMapFunction<String, Request>() {
>>>
>>>     private ObjectMapper objectMapper;
>>>
>>>         public void open() {
>>>             objectMapper = new ObjectMapper();
>>>         }
>>>
>>>         @Override
>>>              public Request map(String value) throws Exception {
>>>                  return objectMapper.readValue(value, Request.class);
>>>         }
>>> })
>>>
>>> But this code gave me a NullPointerException because the objectMapper
>>> was not initialized successfully.
>>>
>>> 1. Isn't the open() method supposed to be called before map() and
>>> initialize objectMapper?
>>> 2. I figured out that initializing objectMapper before the open() method
>>> resolves the problem, and that it works also with a simple MapFunction. In
>>> that case, is there an advantage for using a RichMapFunction?
>>>
>>> Best,
>>> Yassine
>>>
>>
>>
>
>
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