java - Dependency object be saved as instance variable or just the values obtained from getters? -

consider example of simple 'mycalendar' class 3 getters 'getday, getmonth, , getyear'. if pass 'mycalendar' object class of following options approach.

option 1: call required parameters through injected object's getters when needed.

class foo {     mycalendar mycal;     class foo(mycalendar mycal) {         this.mycal = mycal     } } 

or

option 2: assign values obtained injected object's getter part of initialization.

class foo {     day d;     month m;     year y;     class foo(mycalendar mycal) {         d = mycal.getday();         m = mycal.getmonth();         y = mycal.getyear();     } } 

if answer choice 1 : if field needs accessed mutiple times in loop: (..some imaginary usecase) { mycal.getdate(); } in case benefit have local copy ?

use option 1. sound option oriented approach. can delegate tasks calendar object have created. reason see make copy if original data mutable , not want field in foo change, preserve in object form, make copy.