java - providing granular data for data intensive web service -

i developing webservice data intensive. unfortunately of data returned not needed calls, might needed call.

an overly simplified response might below:

 response : {     a,     b,     c,     d : {         x : {          }         y,         z     } } 

i want provide flexibility callers such can request specific data big object. thought of achieving exposing enums, , taking list of enum input. each enum map field in response.

example if caller needs , d, can specify passing list of enums immutablelist.of(get_enum_a, get_enum_d) , @ web service end can compute , d.

questions: there better way of taking input (other enum) of data needed caller?

i give control user on more fine grained data, eg. can specify part of d needed. get_enum_d_x.

at server end, thinking of implementing using command pattern, having command each enum , executing if corresponding enum present in list.

• here d facade.
• if granular data requested don't use facade instead use command x.

issue can think of:

• i end many commands.
• if command subset of command , both requested execute superset command (we need in code)

is there better way of solving problem.

(ps : not interested in fragmenting smaller apis, because of use cases).

if using jackson serialize objects can take advantage of views:

http://wiki.fasterxml.com/jacksonjsonviews

basically, define view class , when serializing object pass in view want. example:

// view definitions: class views {         static interface { }         static interface b { }         static interface c { }         static class ac implements a, c { } }  public class bean {          @jsonview(views.a.class)          public object geta() {           // compute         }         @jsonview(views.b.class)          public object getb() {           // compute b         }         @jsonview(views.c.class)          public object getc() {           // compute c         } } 

then, when want serialize can pass in view want:

objectmapper.writevalueusingview(out, beaninstance, a.class); 

if want both , c use ac class

objectmapper.writevalueusingview(out, beaninstance, ac.class);