Use Short.parseShort instead of valueOf to avoid boxing
diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/util/HexString.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/util/HexString.java
index eaeed5f..bcc46f7 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/util/HexString.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/util/HexString.java
@@ -92,7 +92,7 @@
         for (String octet: octets) {
             if (octet.length() > 2)
                 throw new NumberFormatException("Each colon-separated byte component must consist of 1 or 2 hex digits: " + value);
-            short s = Short.valueOf(octet, 16);
+            short s = Short.parseShort(octet, 16);
             l = (l << 8) + s;
         }
         return l;