android - Send ArrayList inside ArrayList -

i have arraylist (a) contains 2 arraylists(b) , getting a's data json file, in first activity can see , b both not empty, when pass activity or fragment, stays full b becomes empty, objects used implements parcelable, snippet of code used send , retrieve data :

           intent myintent = new intent(launcheractivity.this, acceuilactivity.class);                     myintent.putparcelablearraylistextra("listeoffres",projectslist);                     startactivity(myintent);                     finish(); 

and how retrieve contains b offreslist=getintent().getparcelablearraylistextra("listeoffres");

check parceble model file. let's take example of user here , check below code. also, check argument used passing arraylist in intent. if may not please provide more details.

protected user(parcel in) {     name = in.readstring();     ....     gender = in.readstring(); }   @override public void writetoparcel(parcel parcel, int i) {     parcel.writestring(name);     ....     parcel.writestring(gender); }