public Injector() 
{

}

 public Injector(Configuration conf) 
{
    setConf(conf);
}

 public  void inject(Path crawlDb,
    Path urlDir) throws IOException 
{
    if (LOG.isInfoEnabled()) {
      LOG.info("Injector: starting");
      LOG.info("Injector: crawlDb: " + crawlDb);
      LOG.info("Injector: urlDir: " + urlDir);
    }
    Path tempDir =
      new Path(getConf().get("mapred.temp.dir", ".") +
               "/inject-temp-"+
               Integer.toString(new Random().nextInt(Integer.MAX_VALUE)));
    // map text input file to a < url,CrawlDatum > file
    if (LOG.isInfoEnabled()) {
      LOG.info("Injector: Converting injected urls to crawl db entries.");
    }
    JobConf sortJob = new NutchJob(getConf());
    sortJob.setJobName("inject " + urlDir);
    FileInputFormat.addInputPath(sortJob, urlDir);
    sortJob.setMapperClass(InjectMapper.class);
    FileOutputFormat.setOutputPath(sortJob, tempDir);
    sortJob.setOutputFormat(SequenceFileOutputFormat.class);
    sortJob.setOutputKeyClass(Text.class);
    sortJob.setOutputValueClass(CrawlDatum.class);
    sortJob.setLong("injector.current.time", System.currentTimeMillis());
    JobClient.runJob(sortJob);
    // merge with existing crawl db
    if (LOG.isInfoEnabled()) {
      LOG.info("Injector: Merging injected urls into crawl db.");
    }
    JobConf mergeJob = CrawlDb.createJob(getConf(), crawlDb);
    FileInputFormat.addInputPath(mergeJob, tempDir);
    mergeJob.setReducerClass(InjectReducer.class);
    JobClient.runJob(mergeJob);
    CrawlDb.install(mergeJob, crawlDb);
    // clean up
    FileSystem fs = FileSystem.get(getConf());
    fs.delete(tempDir, true);
    if (LOG.isInfoEnabled()) { LOG.info("Injector: done"); }
}

 public static  void main(String[] args) throws Exception 
{
    int res = ToolRunner.run(NutchConfiguration.create(), new Injector(), args);
    System.exit(res);
}

 public int run(String[] args) throws Exception 
{
    if (args.length <  2) {
      System.err.println("Usage: Injector < crawldb > < url_dir >");
      return -1;
    }
    try {
      inject(new Path(args[0]), new Path(args[1]));
      return 0;
    } catch (Exception e) {
      LOG.fatal("Injector: " + StringUtils.stringifyException(e));
      return -1;
    }
}