java - What are all the @Configuration naming rules for beans? -

i have integration tests supposed mock out 1 of many beans in system. this, have @configuration looks this:

@configuration public class mockcontext {     @primary     @bean     public realbean realbean() {         return new mockbean();     } } 

i noticed method gets used if realbean java class without @component. if realbean is @component, have change context method this:

@configuration public class mockcontext {     @primary     @bean     public realbean getrealbean() {         return new mockbean();     } } 

can explain why need change method name , can find these rules? takes long time troubleshoot these "why isn't mockcontext working correctly?" issues.

fwiw, here's how i'm using context in test:

@runwith(springjunit4classrunner.class) @springapplicationconfiguration(classes = {realcontext.class, mockcontext.class}) @webappconfiguration public abstract class abstractintegrationtest { 

and integration test extend class. using spring boot 1.2.4.release

you can have various beans registered same type. need have different names.

if use @bean annotation without name attribute, name of bean extracted method name (in case realbean/getrealbean).

when use @component annotation without attribute (which specifies bean name), name of bean extracted method name first letter lowercased.

so first case, name clash. can't have 2 beans named realbean.

your second example without clash because bean annotated @component has name realbean , second bean registered via @bean has name getrealbean.

@primary annotation helps spring choose bean pick if there 2 of same type , inject type. when inject name (usage of @qualifier annotation), can inject secondary instance.