exception de pointeur nul - J'ai Eclipse Hadoop à distance

Question

seaching depuis plusieurs jours, S'il vous plaît AIDER

J'ai un NullPointerException lors de l'exécution d'un simple Wordcount pour Hadoop (j'ai installé un cluster de machines virtuelles Ubuntu 14 de Hadoop et d'Eclipse localY)

java.lang.NullPointerException 
    at java.lang.ProcessBuilder.start(Unknown Source) 
    at org.apache.hadoop.util.Shell.runCommand(Shell.java:482) 
    at org.apache.hadoop.util.Shell.run(Shell.java:455) 
    at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:715) 
    at org.apache.hadoop.util.Shell.execCommand(Shell.java:808) 
    at org.apache.hadoop.util.Shell.execCommand(Shell.java:791) 
    at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:656) 
    at org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:444) 
    at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:293) 
    at org.apache.hadoop.mapreduce.JobSubmissionFiles.getStagingDir(JobSubmissionFiles.java:133) 
    at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:437) 
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1296) 
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1293) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at javax.security.auth.Subject.doAs(Unknown Source) 
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1628) 
    at org.apache.hadoop.mapreduce.Job.submit(Job.java:1293) 
    at org.apache.hadoop.mapred.JobClient$1.run(JobClient.java:562) 
    at org.apache.hadoop.mapred.JobClient$1.run(JobClient.java:557) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at javax.security.auth.Subject.doAs(Unknown Source) 
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1628) 
    at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:557) 
    at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:548) 
    at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:833) 
    at WordCount.main(WordCount.java:76) 

Ceci est mon code:

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStreamReader; 

import org.apache.hadoop.fs.FileStatus; 
import org.apache.hadoop.fs.FileSystem; 
import org.apache.hadoop.fs.Path; 
import org.apache.hadoop.io.IntWritable; 
import org.apache.hadoop.io.Text; 
import org.apache.hadoop.mapred.FileInputFormat; 
import org.apache.hadoop.mapred.FileOutputFormat; 
import org.apache.hadoop.mapred.JobClient; 
import org.apache.hadoop.mapred.JobConf; 
//import org.apache.log4j.Logger; 


public class WordCount { 

    public static void main(String[] args) throws IOException { 


    JobConf conf = new JobConf(WordCount.class); 

    System.setProperty("HADOOP_USER_NAME", "hduser"); 
    // specify output types 
    conf.setOutputKeyClass(Text.class); 
    conf.setOutputValueClass(IntWritable.class); 
    conf.set("hadoop.job.ugi", "hduser"); 
    conf.set("fs.defaultFS", "hdfs://10.99.99.2:54310/user/hduser"); 
    //log4j.logger.org.apache.hadoop = DEBUG 
    conf.set("mapred.job.tracker", "10.99.99.2:54311"); 




    // specify input and output dirs 
    FileInputFormat.addInputPath(conf, new Path("input")); //hdfs://10.99.99.2:54310/user/hduser/input/Good.txt 
    FileOutputFormat.setOutputPath(conf, new Path("output")); 

    // specify a mapper 
    conf.setMapperClass(WordCountMapper.class); 

    // specify a reducer 
    conf.setReducerClass(WordCountReducer.class); 
    conf.setCombinerClass(WordCountReducer.class); 



    FileSystem fs = FileSystem.get(conf); 


    // CREATE FILE AND PRINT PATH TO CHECK IS EVERYTHING IS OK 
    fs.createNewFile(new Path("/user/hduser/test")); 

    FileStatus[] status = fs.listStatus(new Path("/user/hduser")); 
    for(int i=0;i<status.length;i++){ 
     System.out.println(status[i].getPath()); 

    } 


    // READ TXT TO BE SURE THERE IS NOT PERMISSION PROBLEM 
    Path pt= new Path("hdfs://10.99.99.2:54310/user/hduser/input/Good.txt"); 
    BufferedReader br=new BufferedReader(new InputStreamReader(fs.open(pt))); 
    String line; 
    line=br.readLine(); 
    while (line != null){ 
      System.out.println(line); 
      line=br.readLine(); } 

    JobClient client = new JobClient(conf); 
    client.setConf(conf); 


    try { 
     JobClient.runJob(conf); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
    } 
} 

Answer 1

Le code semble bien! Veuillez vous assurer que vous donnez une commande précise pour répondre au fichier JAR et que vous pouvez aussi faire des tests et les déboguer pour comprendre d'où vient l'exception du pointeur nul.