code: package edu.jhu.thrax.hadoop.tools;
  
  import java.util.Map;
  
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.conf.Configured;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.io.FloatWritable;
  import org.apache.hadoop.io.IntWritable;
  import org.apache.hadoop.mapreduce.Job;
  import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
  import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
  import org.apache.hadoop.mapreduce.lib.output.SequenceFileOutputFormat;
  import org.apache.hadoop.mapreduce.lib.reduce.IntSumReducer;
  import org.apache.hadoop.util.Tool;
  import org.apache.hadoop.util.ToolRunner;
  
  import edu.jhu.thrax.hadoop.datatypes.TextPair;
  import edu.jhu.thrax.hadoop.features.WordLexicalProbabilityCalculator;
  import edu.jhu.thrax.hadoop.jobs.WordLexprobJob;
  import edu.jhu.thrax.util.ConfFileParser;
  
  public class TargetWordGivenSourceWordProbabilityTool extends Configured implements Tool
  {
      public int run(String [] argv) throws Exception
      {
          if (argv.length < 1) {
              System.err.println("usage: TargetWordGivenSourceWordProbabilityTool <conf file>");
              return 1;
          }
          String confFile = argv[0];
          Configuration conf = getConf();
          Map<String,String> options = ConfFileParser.parse(confFile);
          for (String opt : options.keySet()) {
              conf.set("thrax." + opt, options.get(opt));
          }
          String input = conf.get("thrax.input-file");
          if (input == null) {
              System.err.println("set input-file key in conf file " + confFile + "!");
              return 1;
          }
          String workDir = conf.get("thrax.work-dir");
          if (workDir == null) {
              System.err.println("set work-dir key in conf file " + confFile + "!");
              return 1;
          }
          if (!workDir.endsWith(Path.SEPARATOR)) {
              workDir += Path.SEPARATOR;
              conf.set("thrax.work-dir", workDir);
          }
  		conf.setBoolean(WordLexprobJob.SOURCE_GIVEN_TARGET, false);
          Job job = new Job(conf, "thrax-tgs-word-lexprob");
  
          job.setJarByClass(WordLexicalProbabilityCalculator.class);
          job.setMapperClass(WordLexicalProbabilityCalculator.Map.class);
          job.setCombinerClass(IntSumReducer.class);
          job.setSortComparatorClass(TextPair.SndMarginalComparator.class);
          job.setPartitionerClass(WordLexicalProbabilityCalculator.Partition.class);
          job.setReducerClass(WordLexicalProbabilityCalculator.Reduce.class);
  
          job.setMapOutputKeyClass(TextPair.class);
          job.setMapOutputValueClass(IntWritable.class);
  
          job.setOutputKeyClass(TextPair.class);
          job.setOutputValueClass(FloatWritable.class);
  
          job.setOutputFormatClass(SequenceFileOutputFormat.class);
  
          FileInputFormat.setInputPaths(job, new Path(input));
          FileOutputFormat.setOutputPath(job, new Path(workDir + "lexprobs_tgs"));
  
          job.submit();
          return 0;
      }
  
      public static void main(String [] argv) throws Exception
      {
          int exit_code = ToolRunner.run(null, new TargetWordGivenSourceWordProbabilityTool(), argv);
          System.exit(exit_code);
      }
  }
  