args struct javaclassname (#247)

diff --git a/request.go b/request.go
index 25908cb..032fbc8 100644
--- a/request.go
+++ b/request.go
@@ -107,6 +107,10 @@
 		}
 		switch t.Kind() {
 		case reflect.Struct:
+			v, ok := v.(POJO)
+			if ok {
+				return v.JavaClassName()
+			}
 			return "java.lang.Object"
 		case reflect.Slice, reflect.Array:
 			if t.Elem().Kind() == reflect.Struct {