Hi Thanks guys. I figured out the issue. Hence i have another question. I am using a third party library and I thought that once I have created the jar file I dont need to specify the dependancies but aparently thats not the case. (error below) Very very naive question...probably stupid. How do i specify third party libraries (jar) in hadoop.
Error: Error: java.lang.ClassNotFoundException: org.json.JSONException at java.net.URLClassLoader$1.run(URLClassLoader.java:202) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:820) at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:865) at org.apache.hadoop.mapreduce.JobContext.getMapperClass(JobContext.java:199) at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:719) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370) at org.apache.hadoop.mapred.Child$4.run(Child.java:255) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:396) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1093) at org.apache.hadoop.mapred.Child.main(Child.java:249) On Thu, May 30, 2013 at 2:02 AM, Pramod N <[email protected]> wrote: > Whatever you are trying to do should work, > Here is the modified WordCount Map > > > public void map(LongWritable key, Text value, Context context) throws > IOException, InterruptedException { String line = value.toString(); > > JSONObject line_as_json = new JSONObject(line); > String text = line_as_json.getString("text"); > StringTokenizer tokenizer = new StringTokenizer(text); while > (tokenizer.hasMoreTokens()) { word.set(tokenizer.nextToken()); > context.write(word, one); } } > > > > > > Pramod N <http://atmachinelearner.blogspot.in> > Bruce Wayne of web > @machinelearner <https://twitter.com/machinelearner> > > -- > > > On Thu, May 30, 2013 at 8:42 AM, Rahul Bhattacharjee < > [email protected]> wrote: > >> Whatever you have mentioned Jamal should work.you can debug this. >> >> Thanks, >> Rahul >> >> >> On Thu, May 30, 2013 at 5:14 AM, jamal sasha <[email protected]>wrote: >> >>> Hi, >>> For some reason, this have to be in java :( >>> I am trying to use org.json library, something like (in mapper) >>> JSONObject jsn = new JSONObject(value.toString()); >>> >>> String text = (String) jsn.get("text"); >>> StringTokenizer itr = new StringTokenizer(text); >>> >>> But its not working :( >>> It would be better to get this thing properly but I wouldnt mind using a >>> hack as well :) >>> >>> >>> On Wed, May 29, 2013 at 4:30 PM, Michael Segel < >>> [email protected]> wrote: >>> >>>> Yeah, >>>> I have to agree w Russell. Pig is definitely the way to go on this. >>>> >>>> If you want to do it as a Java program you will have to do some work on >>>> the input string but it too should be trivial. >>>> How formal do you want to go? >>>> Do you want to strip it down or just find the quote after the text >>>> part? >>>> >>>> >>>> On May 29, 2013, at 5:13 PM, Russell Jurney <[email protected]> >>>> wrote: >>>> >>>> Seriously consider Pig (free answer, 4 LOC): >>>> >>>> my_data = LOAD 'my_data.json' USING >>>> com.twitter.elephantbird.pig.load.JsonLoader() AS json:map[]; >>>> words = FOREACH my_data GENERATE $0#'author' as author, >>>> FLATTEN(TOKENIZE($0#'text')) as word; >>>> word_counts = FOREACH (GROUP words BY word) GENERATE group AS word, >>>> COUNT_STAR(words) AS word_count; >>>> STORE word_counts INTO '/tmp/word_counts.txt'; >>>> >>>> It will be faster than the Java you'll likely write. >>>> >>>> >>>> On Wed, May 29, 2013 at 2:54 PM, jamal sasha <[email protected]>wrote: >>>> >>>>> Hi, >>>>> I am stuck again. :( >>>>> My input data is in hdfs. I am again trying to do wordcount but there >>>>> is slight difference. >>>>> The data is in json format. >>>>> So each line of data is: >>>>> >>>>> {"author":"foo", "text": "hello"} >>>>> {"author":"foo123", "text": "hello world"} >>>>> {"author":"foo234", "text": "hello this world"} >>>>> >>>>> So I want to do wordcount for text part. >>>>> I understand that in mapper, I just have to pass this data as json and >>>>> extract "text" and rest of the code is just the same but I am trying to >>>>> switch from python to java hadoop. >>>>> How do I do this. >>>>> Thanks >>>>> >>>> >>>> >>>> >>>> -- >>>> Russell Jurney twitter.com/rjurney [email protected] >>>> datasyndrome.com >>>> >>>> >>>> >>> >> >
