Reimplement the shortest path computation by using the new DataPath and FlowEntry containers.
diff --git a/src/main/java/net/floodlightcontroller/util/DataPath.java b/src/main/java/net/floodlightcontroller/util/DataPath.java
index 9ec9380..71e0a2f 100644
--- a/src/main/java/net/floodlightcontroller/util/DataPath.java
+++ b/src/main/java/net/floodlightcontroller/util/DataPath.java
@@ -19,6 +19,7 @@
      * Default constructor.
      */
     public DataPath() {
+	flowEntries = new ArrayList<FlowEntry>();
     }
 
     /**