Merge pull request #2284 from zakkak/fix-null-meta-object

forObject is expecting an Object not its Class

Author: harawata

src/main/java/org/apache/ibatis/reflection/SystemMetaObject.java

@@ -27,7 +27,7 @@ public final class SystemMetaObject {
 
   public static final ObjectFactory DEFAULT_OBJECT_FACTORY = new DefaultObjectFactory();
   public static final ObjectWrapperFactory DEFAULT_OBJECT_WRAPPER_FACTORY = new DefaultObjectWrapperFactory();
-  public static final MetaObject NULL_META_OBJECT = MetaObject.forObject(NullObject.class, DEFAULT_OBJECT_FACTORY, DEFAULT_OBJECT_WRAPPER_FACTORY, new DefaultReflectorFactory());
+  public static final MetaObject NULL_META_OBJECT = MetaObject.forObject(new NullObject(), DEFAULT_OBJECT_FACTORY, DEFAULT_OBJECT_WRAPPER_FACTORY, new DefaultReflectorFactory());
 
   private SystemMetaObject() {
     // Prevent Instantiation of Static Class