Q: Getting NullPointerException while running a normal Mapreduce program in Eclipse I am getting NullPointerException when trying to execute a simple MapReduce program. I am unable to understand where the problem is?
package MapReduce.HadMapReduce;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

public class RecCount extends Configured implements Tool {

    public int run(String[] arg0) throws Exception {

        Job job = Job.getInstance(getConf());

        FileInputFormat.setInputPaths(job, new Path("C:\\singledeck.txt"));
        FileOutputFormat.setOutputPath(job, new Path("C:\\temp123"));

        return job.waitForCompletion(true) ? 0 : 1;
    }

    public static void main(String args[]) throws Exception {
        System.exit(ToolRunner.run(new RecCount(), args));
    }
}

Error is:
Exception in thread "main" java.lang.NullPointerException
    at java.lang.ProcessBuilder.start(ProcessBuilder.java:1010)
    at org.apache.hadoop.util.Shell.runCommand(Shell.java:483)
    at org.apache.hadoop.util.Shell.run(Shell.java:456)
    at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:722)
    at org.apache.hadoop.util.Shell.execCommand(Shell.java:815)
    at org.apache.hadoop.util.Shell.execCommand(Shell.java:798)
    at org.apache.hadoop.fs.RawLocalFileSystem.setPermission(RawLocalFileSystem.java:731)
    at org.apache.hadoop.fs.RawLocalFileSystem.mkOneDirWithMode(RawLocalFileSystem.java:489)
    at org.apache.hadoop.fs.RawLocalFileSystem.mkdirsWithOptionalPermission(RawLocalFileSystem.java:530)
    at org.apache.hadoop.fs.RawLocalFileSystem.mkdirs(RawLocalFileSystem.java:507)
    at org.apache.hadoop.fs.FilterFileSystem.mkdirs(FilterFileSystem.java:305)
    at org.apache.hadoop.mapreduce.JobSubmissionFiles.getStagingDir(JobSubmissionFiles.java:133)
    at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:144)
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1290)
    at org.apache.hadoop.mapreduce.Job$10.run(Job.java:1287)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:415)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
    at org.apache.hadoop.mapreduce.Job.submit(Job.java:1287)
    at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1308)
    at MapReduce.HadMapReduce.RecCount.run(RecCount.java:22)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
    at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84)
    at MapReduce.HadMapReduce.RecCount.main(RecCount.java:26)

This is the logic which is happening behind the scenes: 
ToolRunner is calling the below run method and this method calls its other run method (which is pasted right below this) where the configuration is set if it is null.
public static int run(Tool tool, String[] args) throws Exception {
    return run(tool.getConf(), tool, args);
}        

public static int run(Configuration conf, Tool tool, String[] args) throws  Exception {
    if (conf == null) {
        conf = new Configuration();
    }
    GenericOptionsParser parser = new GenericOptionsParser(conf, args);
    // set the configuration back, so that Tool can configure itself
    tool.setConf(conf);

    // get the args w/o generic hadoop args
    String[] toolArgs = parser.getRemainingArgs();
    return tool.run(toolArgs);
}

In the last statement above run method is called which I implemented because I implemented Tool interface. I don't see any error in my code. Please let me know if you can find any!
Can someone please explain what is the problem with my code?
