tojsonstring(json.java:418) coba.fastjson.json.tojsonstring(json.java:406) coe(action.java:68) sun.reflect.generatedessor38.invoke(unknown source) sun.reflect.delegatingpl.invoke(unknown source) java.lang.reflect.method.invoke(unknown source) com.opensyctioninvocation.invokeaction(defaultactioninvocation.java:452) com.