Updated docs in ResourceDef to indicate what id is used for (potentially it's also used for other things, though I didn't find any)

Added a test that demonstrates using ResourceDef.id to set the id for a custom resource's profile

hapi-fhir-base/src/main/java/ca/uhn/fhir/model/api/annotation/ResourceDef.java

@@ -38,7 +38,7 @@ public @interface ResourceDef {
 	String name() default "";
 
 	/**
-	 * Not currently used
+	 * if set, will be used as the id for any profiles generated for this resource
 	 */
 	String id() default "";
 	

hapi-fhir-structures-dstu/src/test/java/ca/uhn/fhir/context/CustomObservation.java

@@ -0,0 +1,30 @@
+package ca.uhn.fhir.context;
+
+import ca.uhn.fhir.model.api.annotation.Child;
+import ca.uhn.fhir.model.api.annotation.Description;
+import ca.uhn.fhir.model.api.annotation.Extension;
+import ca.uhn.fhir.model.api.annotation.ResourceDef;
+import ca.uhn.fhir.model.dstu.resource.Observation;
+import ca.uhn.fhir.model.primitive.StringDt;
+
+/**
+ * Created by Bill de Beaubien on 10/31/2014.
+ */
+@ResourceDef(name="Observation", id="customobservation")
+public class CustomObservation extends Observation {
+    @Child(name = "valueUnits", order = 3)
+    @Extension(url = "http://hapi.test.com/profile/customobservation#valueUnits", definedLocally = true, isModifier = false)
+    @Description(shortDefinition = "Units on an observation whose type is of valueString")
+    private StringDt myValueUnits;
+
+    public StringDt getValueUnits() {
+        if (myValueUnits == null) {
+            myValueUnits = new StringDt();
+        }
+        return myValueUnits;
+    }
+
+    public void setValueUnits(StringDt theValueUnits) {
+        myValueUnits = theValueUnits;
+    }
+}

hapi-fhir-structures-dstu/src/test/java/ca/uhn/fhir/context/RuntimeResourceDefinitionTest.java

@@ -92,4 +92,14 @@ public class RuntimeResourceDefinitionTest {
 
 	}
 
+	@Test
+	public void testProfileIdIsActualResourceName() {
+		FhirContext ctx = new FhirContext(CustomObservation.class);
+		RuntimeResourceDefinition def = ctx.getResourceDefinition(CustomObservation.class);
+
+		Profile profile = (Profile) def.toProfile();
+
+		assertEquals("customobservation", profile.getId().toString());
+	}
+
 }