java - Class Main$MapClass not found on EMR -

i trying run map-reduce job on emr (amazon) after checked on local computer , i'm getting error:

error: java.lang.runtimeexception: java.lang.classnotfoundexception: class main$mapclass not found @ org.apache.hadoop.conf.configuration.getclass(configuration.java:1720) @ org.apache.hadoop.mapreduce.task.jobcontextimpl.getmapperclass(jobcontextimpl.java:186) @ org.apache.hadoop.mapred.maptask.runnewmapper(maptask.java:733) @ org.apache.hadoop.mapred.maptask.run(maptask.java:342) @ org.apache.hadoop.mapred.yarnchild$2.run(yarnchild.java:162) @ java.security.accesscontroller.doprivileged(native method) @ javax.security.auth.subject.doas(subject.java:415) @ org.apache.hadoop.security.usergroupinformation.doas(usergroupinformation.java:1491) @ org.apache.hadoop.mapred.yarnchild.main(yarnchild.java:157) caused by: java.lang.classnotfoundexception: class main$mapclass not found @ org.apache.hadoop.conf.configuration.getclassbyname(configuration.java:1626) @ org.apache.hadoop.conf.configuration.getclass(configuration.java:1718) ... 8 more 

this main function define job configuration:

    public static void main(string[] args) throws exception {     string inputlocation;     string outputlocation;     string includestopwords;      if (args.length > 2) {         inputlocation = args[0];         outputlocation = args[1];         includestopwords = args[2];     }else{         for(int i=0; < args.length; i++){             system.out.println("missing args!!\n" + "number of args: "+ args.length+ "\n args[" + i+ "]:" + args[i]);         }         throw new illegalargumentexception();     }       // first job - count 2 grams words decade     configuration conf = new configuration();     conf.set("includestopwords", includestopwords);     @suppresswarnings("deprecation")     job job = new job(conf, "words count");     system.out.println("before set classes:");       job.setjarbyclass(main.class);     job.setmapperclass(mapclass.class);     job.setreducerclass(reduceclass.class);     system.out.println("after setting classes.");     job.setoutputkeyclass(text.class);     job.setoutputvalueclass(text.class);     job.setmapoutputkeyclass(text.class);     job.setmapoutputvalueclass(text.class); //  job.setinputformatclass(sequencefileinputformat.class);     fileinputformat.addinputpath(job, new path(inputlocation));     fileoutputformat.setoutputpath(job, new path(outputlocation));     system.out.println("before wait complition");     system.exit(job.waitforcompletion(true) ? 0 : 1);     system.out.println("after wait completion");   } 

the code of runner on emr is:

public class runner { public static logger logger = logmanager.getrootlogger();  public static void main(string[] args) throws ioexception {      string minpmi;     string relminpmi;     string language;     string includestopwords;     if(args.length > 3){         minpmi = args[0];         relminpmi = args[1];         language = args[2];         includestopwords = args[3];      }else{         system.out.println("missing arguments!");         throw new illegalargumentexception();     }       //jobs output locations     string firstoutput = "s3n://dsp152ass2/outputs/first";     string secondoutput = "s3n://dsp152ass2/outputs/second";     string thirdoutput = "s3n://dsp152ass2/outputs/third";      //jobs jar location     string firstjobjar = "s3n://dsp152ass2/jars/firstjob.jar";     string secondjobjar = "s3n://dsp152ass2/jars/secondjob.jar";     string thirdjobjar = "s3n://dsp152ass2/jars/thirdjob.jar";      //select input corpus language argument     string corpus = "s3n://dsp152/output/eng-us-all-100k-2gram"; //todo: change real input     if(language.equalsignorecase("heb")){         corpus = "s3n://dsp152/output/heb-all-100k-2gram";     }        //create emr      awscredentials credentials = new propertiescredentials(new fileinputstream(new file("credentials.properties")));     amazonelasticmapreduce mapreduce = new amazonelasticmapreduceclient(credentials);      //define hadoop steps config     hadoopjarstepconfig firstjobconfing = new hadoopjarstepconfig()     .withjar(firstjobjar)       //.withmainclass("firstmr.main") // sec runner     .withargs(corpus, firstoutput , includestopwords);      hadoopjarstepconfig secondjobconfing = new hadoopjarstepconfig()     .withjar(secondjobjar) //  .withmainclass("main")     .withargs(firstoutput +"/part-r-00000" , secondoutput);      hadoopjarstepconfig thirdjobconfing = new hadoopjarstepconfig()     .withjar(thirdjobjar)      //.withmainclass("main")     .withargs(secondoutput+"/part-r-00000", thirdoutput , minpmi, relminpmi);        //define step config     stepconfig firstjobstep = new stepconfig()     .withname("firstjobstep")     .withhadoopjarstep(firstjobconfing)     .withactiononfailure("terminate_job_flow");      stepconfig secondjobstep = new stepconfig()     .withname("secondjobstep")     .withhadoopjarstep(secondjobconfing)     .withactiononfailure("terminate_job_flow");      stepconfig thirdjobstep = new stepconfig()     .withname("thirdjobstep")     .withhadoopjarstep(thirdjobconfing)     .withactiononfailure("terminate_job_flow");       //define job flow     jobflowinstancesconfig instances = new jobflowinstancesconfig()     .withinstancecount(1) //todo: change 2 - 10     .withmasterinstancetype(instancetype.m1large.tostring())     .withslaveinstancetype(instancetype.m1large.tostring())     .withhadoopversion("2.2.0").withec2keyname("dsp152ass2")     .withkeepjobflowalivewhennosteps(false)     .withplacement(new placementtype("us-east-1b"));        //define run flow     runjobflowrequest runflowrequest = new runjobflowrequest()     .withname("dspextractcollections")       .withinstances(instances)     .withjobflowrole("emr_ec2_defaultrole")     .withservicerole("emr_defaultrole")     .withsteps(firstjobstep,secondjobstep,thirdjobstep)     .withloguri("s3n://dsp152ass2/logs/");        //run jobs     runjobflowresult runjobflowresult = mapreduce.runjobflow(runflowrequest);     string jobflowid = runjobflowresult.getjobflowid();     system.out.println("### workflow added: \n" + "\t" + jobflowid);  } 

}

my project structure:

thanks in advance help.

these steps can solve resolution problem:

1. create separate mapper , reducer classes.
2. create package name classes , use , not default package (foo.main, foo.mapclass ...).
3. when you're in eclipse, try "extract required libraries generated jar" option, instead of "package required libraries generated jar". may solve classes not being found (make sure copy eclipse generated).

tip: emr has specific settings not running local (and pseudo-distributed) deployment. make sure correct following aws's guide.