In order to get the 2.2 source to compile I needed to apply the following patch:
Code:
diff -u -r Downloads/directjngine.2.2/src/prod/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java ./src/prod/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java
--- Downloads/directjngine.2.2/src/prod/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java    2012-05-20 19:34:52.000000000 +1000
+++ ./src/prod/com/google/gson/internal/bind/ReflectiveTypeAdapterFactory.java    2013-10-03 14:00:26.000000000 +1000
@@ -73,7 +73,7 @@
     return new Adapter<T>(constructor, getBoundFields(gson, type, raw));
   }
 
-  private ReflectiveTypeAdapterFactory.BoundField createBoundField(
+  private static ReflectiveTypeAdapterFactory.BoundField createBoundField(
       final Gson context, final Field field, final String name,
       final TypeToken<?> fieldType, boolean serialize, boolean deserialize) {
     final boolean isPrimitive = Primitives.isPrimitive(fieldType.getRawType());
HTH. Scott