BeanDefinition的getRole方法,用于标识Bean的分类

public class RoleAndDescriptionAnnotationTests {

    @Test
    public void onBeanMethod() {
        AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
        ctx.register(Config.class);
        ctx.refresh();
        assertThat("Expected bean to have ROLE_APPLICATION",
                ctx.getBeanDefinition("foo").getRole(), is(BeanDefinition.ROLE_APPLICATION));
        assertThat(ctx.getBeanDefinition("foo").getDescription(), is((Object) null));
        assertThat("Expected bean to have ROLE_INFRASTRUCTURE",
                ctx.getBeanDefinition("bar").getRole(), is(BeanDefinition.ROLE_INFRASTRUCTURE));
        assertThat(ctx.getBeanDefinition("bar").getDescription(), is("A Bean method with a role"));
    }

    @Test
    public void onComponentClass() {
        AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
        ctx.register(ComponentWithoutRole.class, ComponentWithRole.class);
        ctx.refresh();
        assertThat("Expected bean to have ROLE_APPLICATION",
                ctx.getBeanDefinition("componentWithoutRole").getRole(), is(BeanDefinition.ROLE_APPLICATION));
        assertThat(ctx.getBeanDefinition("componentWithoutRole").getDescription(), is((Object) null));
        assertThat("Expected bean to have ROLE_INFRASTRUCTURE",
                ctx.getBeanDefinition("componentWithRole").getRole(), is(BeanDefinition.ROLE_INFRASTRUCTURE));
        assertThat(ctx.getBeanDefinition("componentWithRole").getDescription(), is("A Component with a role"));
    }


    @Test
    public void viaComponentScanning() {
        AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
        ctx.scan("org.springframework.context.annotation.role");
        ctx.refresh();
        assertThat("Expected bean to have ROLE_APPLICATION",
                ctx.getBeanDefinition("componentWithoutRole").getRole(), is(BeanDefinition.ROLE_APPLICATION));
        assertThat(ctx.getBeanDefinition("componentWithoutRole").getDescription(), is((Object) null));
        assertThat("Expected bean to have ROLE_INFRASTRUCTURE",
                ctx.getBeanDefinition("componentWithRole").getRole(), is(BeanDefinition.ROLE_INFRASTRUCTURE));
        assertThat(ctx.getBeanDefinition("componentWithRole").getDescription(), is("A Component with a role"));
    }


    @Configuration
    static class Config {
        @Bean
        public String foo() {
            return "foo";
        }

        @Bean
        @Role(BeanDefinition.ROLE_INFRASTRUCTURE)
        @Description("A Bean method with a role")
        public String bar() {
            return "bar";
        }
    }

}