Thanks Drake. That was the point.It was my mistake. On Mon, Feb 23, 2015 at 6:34 AM, Drake민영근 <drake....@nexr.com> wrote:
> Hi, unmesha. > > I think this is a gson problem. you mentioned like this: > > >> But parsing canot be done in *MR2*. > *>> TreeInfoWritable info = gson.toJson(setupData, > TreeInfoWritable.class);* > > I think just use gson.fromJson, not toJson(setupData is already json > string, i think). > > Is this right ? > > Drake 민영근 Ph.D > kt NexR > > On Sat, Feb 21, 2015 at 4:55 PM, unmesha sreeveni <unmeshab...@gmail.com> > wrote: > >> Am I able to get the values from writable of a previous job. >> ie I have 2 MR jobs >> *MR 1:* >> I need to pass 3 element as values from reducer and the key is >> NullWritable. So I created a custom writable class to achieve this. >> * public class TreeInfoWritable implements Writable{* >> >> * DoubleWritable entropy;* >> * IntWritable sum;* >> * IntWritable clsCount;* >> * ..* >> *}* >> *MR 2:* >> I need to access MR 1 result in MR2 mapper setup function. And I >> accessed it as distributed cache (small file). >> Is there a way to get those values using get method. >> *while ((setupData = bf.readLine()) != null) {* >> * System.out.println("Setup Line "+setupData);* >> * TreeInfoWritable info = //something i can pass to TreeInfoWritable and >> get values* >> * DoubleWritable entropy = info.getEntropy();* >> * System.out.println("entropy: "+entropy);* >> *}* >> >> Tried to convert writable to gson format. >> *MR 1* >> *Gson gson = new Gson();* >> *String emitVal = gson.toJson(valEmit);* >> *context.write(out, new Text(emitVal));* >> >> But parsing canot be done in *MR2*. >> *TreeInfoWritable info = gson.toJson(setupData, TreeInfoWritable.class);* >> >> *Error: Type mismatch: cannot convert from String to TreeInfoWritable* >> Once it is changed to string we cannot get values. >> >> Am I able to get a workaround for the same. or to use just POJO classes >> instaed of Writable. I'm afraid if that becomes slower as we are depending >> on Java instaed of hadoop 's serializable classes >> >> >> >> >> > -- *Thanks & Regards * *Unmesha Sreeveni U.B* *Hadoop, Bigdata Developer* *Centre for Cyber Security | Amrita Vishwa Vidyapeetham* http://www.unmeshasreeveni.blogspot.in/