Hi rdsr, The problem is that you're trying to use the "maxtemperature" as a class name before it's finished compiling. To work around that, use (Class/forName "maxtemperature") instead.
You can also see my (very task-specific) Hadoop/Clojure integration at <http://tinyurl.com/mqv2os> and <http://tinyurl.com/lznlg2>. -SS On Jul 27, 4:55 am, RD <rdsr...@gmail.com> wrote: > Hi all, > I'm having trouble converting the basic hadoop example to clojure. > Here's my code. > > (ns maxtemperature > (:gen-class) > (:import [org.apache.hadoop.io IntWritable Text] > [org.apache.hadoop.mapred > JobConf JobClient > FileInputFormat FileOutputFormat > Mapper Reducer MapReduceBase]) > (:use [clojure.contrib.str-utils :only (re-split)])) > > (gen-class > :name mapper > :extends org.apache.hadoop.mapred.MapReduceBase > :implements [org.apache.hadoop.mapred.Mapper] > :prefix "m-") > > (defn m-map [this key value output-collector reporter] > (let [line (str value) > year (subs line 15 19) > air-temperature (if (= (nth line 87) \+) > (Integer/parseInt (subs line 88 92)) > (Integer/parseInt (subs line 87 92))) > quality (subs line 92 93)] > (if (and (not (= air-temperature 9999)) > (re-matches quality "[01459]")) > (.collect output-collector (Text. year) (IntWritable. > air-temperature))))) > > (gen-class > :name reducer > :extends org.apache.hadoop.mapred.MapReduceBase > :implements [org.apache.hadoop.mapred.Reducer] > :prefix "r-") > > (defn r-reduce [this key values output-collector] > (.collect output-collector key (apply max values))) > > (defn -main [s] > (let [conf (JobConf. maxtemperature) > args (re-split " +" s 2)] > (doto conf > (.setJobName "Max temperature") > (.setMapperClass mapper) > (.setReducerClass reducer) > (.setOutputKeyClass Text) > (.setOutputValueClass IntWritable)) > (FileInputFormat/addInputPath conf (first args)) > (FileOutputFormat/setOutputPath conf (second args)) > (.runJob JobClient conf))) > > (compile 'maxtemperature) > > The problem is that, the compilation step fails when it encounters the > maxtemperature in the main function. > Without the main function the code works fine and even the compilation > succeeds. I can't figure out what's wrong. > Greatly appreciate help on this. > > thanks, > rdsr. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -~----------~----~----~----~------~----~------~--~---
