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MapReduce, mail # user - Re: Reducer to output only json


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Re: Reducer to output only json
Shahab Yunus 2013-06-04, 21:00
Chengi,

You can also see this for pointers:
http://java.dzone.com/articles/hadoop-practice

Regards,
Shahab
On Tue, Jun 4, 2013 at 4:15 PM, Mohammad Tariq <[EMAIL PROTECTED]> wrote:

> Yes...This should do the trick.
>
> Warm Regards,
> Tariq
> cloudfront.blogspot.com
>
>
> On Wed, Jun 5, 2013 at 1:38 AM, Niels Basjes <[EMAIL PROTECTED]> wrote:
>
>> Have you tried something like this (i do not have a pc here to check this
>> code)
>>
>> context.write(NullWritable, new Text(jsn.toString()));
>> On Jun 4, 2013 8:10 PM, "Chengi Liu" <[EMAIL PROTECTED]> wrote:
>>
>>> Hi,
>>>
>>>  I have the following redcuer class
>>>
>>> public static class TokenCounterReducer
>>>     extends Reducer<Text, Text, Text, Text> {
>>>     public void reduce(Text key, Iterable<Text> values, Context context)
>>>         throws IOException, InterruptedException {
>>>
>>>     //String[] fields = s.split("\t", -1)
>>>     JSONObject jsn = new JSONObject();
>>>         int sum = 0;
>>>         for (Text value : values) {
>>>         String[] vals = value.toString().split("\t");
>>>         String[] targetNodes = vals[0].toString().split(",",-1);
>>>         jsn.put("source",vals[1] );
>>>         jsn.put("target",targetNodes);
>>>             //sum += value.get();
>>>         }
>>>        // context.write(key, new Text(sum));
>>>     }
>>> }
>>>
>>> I want to save that json to hdfs?
>>>
>>> It was very trivial in hadoop streaming.. but how do i do it in hadoop
>>> java?
>>> Thanks
>>>
>>
>