java - Cast exception from one class to another -

- 

 session session2 = hibernateutil.getsessionfactory().opensession();         transaction tx2 = session2.begintransaction();        query q=session2.createquery("from studbean1 group sno");         list<student_change> l1=(list<student_change>)q.list();         //student_change sc=new student_change();           for(student_change sc3:l1){            session2.save(sc3);            tx2.commit();            session2.close();

here data coming studbean1 can access data student_change

but gives excption can't cast studbean1 student_change

given have modelled student_change generalisation of studbean1, list<studbean1> not subtype of list<student_change>. try getting list<studbean1>, iterating on , perform cast in loop.

why-is-liststring-not-a-subtype-of-listobject

anyway, there more problems in code should revise (see comments question).


Comments

Post a Comment

Popular posts from this blog

Django REST Framework perform_create: You cannot call `.save()` after accessing `serializer.data` -

-
i have following viewset: class artistprofileviewset(viewsets.modelviewset): queryset = artistprofile.objects.all() serializer_class = artistprofileserializer def perform_create(self, serializer): if serializer.is_valid(): serializer.save() with following serializers: class simpleartisttrackserializer(serializers.hyperlinkedmodelserializer): class meta: model = artisttrack fields = (...my fields...) class artistprofileserializer(serializers.hyperlinkedmodelserializer): owners = userserializer(many=true, required=false) tracks = simpleartisttrackserializer(many=true, required=false) class meta: model = artistprofile fields = (...my fields...) i getting following error: assertionerror: cannot call `.save()` after accessing `serializer.data`.if need access data before committing database inspect 'serializer.validated_data' instead. i don't see editing serializer.data object. th...
Read more

Why does Go error when trying to marshal this JSON? -

-
i'm trying rather simple example of trying decode json file structs using golang. however, when attempting error that json: cannot unmarshal object go value of type []main.track which don't understand. here's code in question, , json can found here . package main import ( "encoding/json" "fmt" "net/http" "os" ) // tracks group of track types type tracks struct { tracks []track } // track represents singular track type track struct { name string url string artist artist } // artist represents single artist type artist struct { name string mbid string url string } func main() { url := "http://ws.audioscrobbler.com/2.0/?method=geo.gettoptracks&api_key=c1572082105bd40d247836b5c1819623&format=json&country=netherlands" response, err := http.get(url) if err != nil { fmt.printf("%s\n", err) os.exit(1) } de...
Read more