flink-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Matthias J. Sax" <mj...@apache.org>
Subject Re: Problem with flink while development
Date Mon, 18 Apr 2016 19:33:17 GMT
If you work on plain Integer (or other non-POJO types) you need to
provide a KeySelector to make it work.

For you case something like this:

.keyBy(new KeySelector<Integer, Integer>() {
	@Override
	public Integer getKey(Integer value) throws Exception {
		return value;
	}
})

As Saikat already mentioned, int-based index access to keys works only
for Flink's Tuple types.

For POJO's you can also access key by name.

https://ci.apache.org/projects/flink/flink-docs-release-1.0/apis/streaming/index.html#datastream-transformations


-Matthias


On 04/18/2016 08:30 PM, Saikat Maitra wrote:
> Hello Jitendra,
> 
>  I am new to Flink community but may have seen this issue earlier. Can you
> try to use DataStream<Tuple1<Integer>> instead of KeyedStream integers4
> 
> Regards Saikat
> 
> On Mon, Apr 18, 2016 at 7:37 PM, Jitendra Agrawal <
> jitendra.agrawal@northgateps.com> wrote:
> 
>> Hi Team,
>>
>> Problem Description :  When I was calling *reduce()* method on keyedStream
>> object then getting Ecxeption as
>>
>> "* org.apache.flink.api.common.InvalidProgramException: Specifying keys via
>> field positions is only valid for tuple data types. Type: Integer*".
>>
>>    StreamExecutionEnvironment env =
>> StreamExecutionEnvironment.getExecutionEnvironment();
>>   KeyedStream integers4 = env.fromElements(1,2,3).keyBy(0);
>>   DataStream doubleIntegers4 = integers4.reduce(new
>> ReduceFunction<Integer>() {
>>
>> @Override
>> public Integer reduce(Integer arg0, Integer arg1) throws Exception {
>> return arg0 + arg1;
>> }
>> });
>>
>>
>> can you please tell me how to solve this exception? or can you provide any
>> link or example where I get these complete Solution..
>>
>> your help will be appreciated..
>>
>> Thanks & Regards
>>
>>  *Jitendra Agrawal *
>>
>> Mumbai
>>
>> 9167539602
>>
>> --
>> This email is sent on behalf of Northgate Public Services (UK) Limited and
>> its associated companies including Rave Technologies (India) Pvt Limited
>> (together "Northgate Public Services") and is strictly confidential and
>> intended solely for the addressee(s).
>> If you are not the intended recipient of this email you must: (i) not
>> disclose, copy or distribute its contents to any other person nor use its
>> contents in any way or you may be acting unlawfully;  (ii) contact
>> Northgate Public Services immediately on +44(0)1908 264500 quoting the name
>> of the sender and the addressee then delete it from your system.
>> Northgate Public Services has taken reasonable precautions to ensure that
>> no viruses are contained in this email, but does not accept any
>> responsibility once this email has been transmitted.  You should scan
>> attachments (if any) for viruses.
>>
>> Northgate Public Services (UK) Limited, registered in England and Wales
>> under number 00968498 with a registered address of Peoplebuilding 2,
>> Peoplebuilding Estate, Maylands Avenue, Hemel Hempstead, Hertfordshire, HP2
>> 4NN.  Rave Technologies (India) Pvt Limited, registered in India under
>> number 117068 with a registered address of 2nd Floor, Ballard House, Adi
>> Marzban Marg, Ballard Estate, Mumbai, Maharashtra, India, 400001.
>>
> 


Mime
View raw message