Hadoop: ToolRunner Interface Is Not Working. ( Use GenericOptionsParser Warning )

Question

I am trying to implement a ToolRunner interface. However, I am still getting the "WARN [JobClient] Use GenericOptionsParser" warning. What am I doing wrong can anyone help ? I used the command

hadoop jar gc.jar stubs.AvgWordLength -D mapred.reduce.tasks=10 myInput.txt myOutput_res

but still no use the WARN message was not suppressed, but the command worked. I have been trying for almost a day and cannot resolve it. Really not sure what I am doing wrong as I am still a beginner.

Ps: I am using it on linux.

Driver/ToolRunner

package stubs;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.DoubleWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

public class AvgWordLength extends Configured implements Tool {

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

        int exitCode = ToolRunner.run(new Configuration(), new AvgWordLength(), args);
        System.exit(exitCode);

    }

    @Override
    public int run(String[] args) throws Exception {
        /*
         * Validate that two arguments were passed from the command line.
         */
        if (args.length != 2) {
            System.out.printf("Usage: AvgWordLength <input dir> <output dir>\n");
            System.exit(-1);
        }

        /*
         * Instantiate a Job object for your job's configuration.
         */
        Job job = Job.getInstance(getConf());

        /*
         * Specify the jar file that contains your driver, mapper, and reducer.
         * Hadoop will transfer this jar file to nodes in your cluster running
         * mapper and reducer tasks.
         */
        job.setJarByClass(AvgWordLength.class);

        /*
         * Specify an easily-decipherable name for the job. This job name will
         * appear in reports and logs.
         */
        job.setJobName("Average Word Length");

        /*
         * Specify the paths to the input and output data based on the
         * command-line arguments.
         */
        FileInputFormat.setInputPaths(job, new Path(args[0]));
        FileOutputFormat.setOutputPath(job, new Path(args[1]));

        /*
         * Specify the mapper and reducer classes.
         */
        job.setMapperClass(LetterMapper.class);
        job.setReducerClass(AverageReducer.class);

        /*
         * The input file and output files are text files, so there is no need
         * to call the setInputFormatClass and setOutputFormatClass methods.
         */

        /*
         * The mapper's output keys and values have different data types than
         * the reducer's output keys and values. Therefore, you must call the
         * setMapOutputKeyClass and setMapOutputValueClass methods.
         */
        job.setMapOutputKeyClass(Text.class);
        job.setMapOutputValueClass(IntWritable.class);

        /*
         * Specify the job's output key and value classes.
         */
        job.setOutputKeyClass(Text.class);
        job.setOutputValueClass(DoubleWritable.class);

        /*
         * Start the MapReduce job and wait for it to finish. If it finishes
         * successfully, return 0. If not, return 1.
         */
        boolean success = job.waitForCompletion(true);
        return (success ? 0 : 1);
    }
}