Index: Injector.java
===================================================================
--- Injector.java	(revision 1589688)
+++ Injector.java	(working copy)
@@ -247,7 +247,14 @@
   public Injector(Configuration conf) {
     setConf(conf);
   }
-  
+  /*
+   * Main function of the injector that reads the urls in the urlDir,
+   * runs the url filters on them,
+   * normalizes them and injects them into the crawldb
+   * @param crawlDB the path to the crawl database (existing or new)
+   * @param urlDir the path to the url directory that contains the urls file
+   * @throws IOException if the urlDir path doesn't exist
+   */
   public void inject(Path crawlDb, Path urlDir) throws IOException {
     SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
     long start = System.currentTimeMillis();
@@ -301,7 +308,9 @@
     long end = System.currentTimeMillis();
     LOG.info("Injector: finished at " + sdf.format(end) + ", elapsed: " + TimingUtil.elapsedTime(start, end));
   }
-
+/*
+ * Entry point for injecting urls into crawldb
+ */
   public static void main(String[] args) throws Exception {
     int res = ToolRunner.run(NutchConfiguration.create(), new Injector(), args);
     System.exit(res);