Is it possible to inject one service into another service in angularJS?
Yes. follow the regular injection rule in angularjs.
app.service('service1', function(){});
//Inject service1 into service2
app.service('service2',function(service1){});
Thanks to @simon. It is better to use Array injection to avoid minifying problem.
app.service('service2',['service1', function(service1) {}]);