Json Parsing in Apache Pig - json

Question

I am Having a json :
{"Name":"sampling","elementInfo":{"fraction":"3"},"destination":"/user/sree/OUT","source":"/user/sree/foo.txt"}
I found that we are able to load json into PigScript.
A = LOAD ‘data.json’
USING PigJsonLoader();
But how to parse json in Apache Pig
--Sampling.pig
--pig -x mapreduce -f Sampling.pig -param input=foo.csv -param output=OUT/pig -param delimiter="," -param fraction='0.05'
--Load data
inputdata = LOAD '$input' using PigStorage('$delimiter');
--Group data
groupedByAll = group inputdata all;
--output into hdfs
sampled = SAMPLE inputdata $fraction;
store sampled into '$output' using PigStorage('$delimiter');
Above is my pig script.
How to parse json (each element) in Apache pig?
I need to take above json as input and parse its source,delimiter,fraction,output and pass in $input,$delimiter,$fraction,$output respectively.
How to parse the same .
Please suggest

Answer 1

Try this :
--Load data
inputdata = LOAD '/input.txt' using JsonLoader('Name:chararray,elementinfo:(fraction:chararray),destionation:chararray,source:chararray');
--Group data
groupedByAll = group inputdata all;
store groupedByAll into '/OUT/pig' using PigStorage(',');
Now your output looks :
all,{(sampling1,(4),/user/sree/OUT1,/user/sree/foo1.txt),(sampling,(3),/user/sree/OUT,/user/sree/foo.txt)}
In input file fraction data {"fraction":"3"} in double quotes. so i used fraction as chararray so can't able to run sample command so i used the above script to get the result.
if you want to perform sample operation cast the fraction data to int and then you will get the result.