Merge pull request #502 from sebastian-nagel/NUTCH-2774-override-annotations

NUTCH-2774 Annotate methods implementing the Hadoop API by @Override
diff --git a/src/plugin/subcollection/src/java/org/apache/nutch/collection/Subcollection.java b/src/plugin/subcollection/src/java/org/apache/nutch/collection/Subcollection.java
index 8478390..36f33ca 100644
--- a/src/plugin/subcollection/src/java/org/apache/nutch/collection/Subcollection.java
+++ b/src/plugin/subcollection/src/java/org/apache/nutch/collection/Subcollection.java
@@ -19,6 +19,7 @@
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Locale;
 import java.util.StringTokenizer;
 
 import org.apache.hadoop.conf.Configuration;
@@ -239,8 +240,10 @@
     while (st.hasMoreElements()) {
       String line = (String) st.nextElement();
       line = line.trim();
+      if (line.isEmpty())
+        continue;
       if (caseInsensitive) {
-        line = line.toLowerCase();
+        line = line.toLowerCase(Locale.ROOT);
       }
       list.add(line);
     }