Remove EntityCreatedObserver and update code where needed

Due to timing issues, the blocking observable could return before the observer has a non null response object. The result could then be "No Content" instead of "Created"

api/metrics-api-jaxrs-1.1/src/main/java/org/hawkular/metrics/api/jaxrs/handler/AvailabilityHandler.java

@@ -18,7 +18,9 @@
 
 import static java.util.concurrent.TimeUnit.HOURS;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
 import static javax.ws.rs.core.MediaType.APPLICATION_JSON;
+
 import static org.hawkular.metrics.api.jaxrs.util.ApiUtils.noContent;
 import static org.hawkular.metrics.api.jaxrs.util.ApiUtils.requestToAvailabilities;
 import static org.hawkular.metrics.api.jaxrs.util.ApiUtils.requestToAvailabilityDataPoints;
@@ -48,8 +50,6 @@
 
 import org.hawkular.metrics.api.jaxrs.ApiError;
 import org.hawkular.metrics.api.jaxrs.filter.TenantFilter;
-import org.hawkular.metrics.api.jaxrs.handler.observer.EntityCreatedObserver;
-import org.hawkular.metrics.api.jaxrs.handler.observer.MetricCreatedObserver;
 import org.hawkular.metrics.api.jaxrs.model.Availability;
 import org.hawkular.metrics.api.jaxrs.model.AvailabilityDataPoint;
 import org.hawkular.metrics.api.jaxrs.param.Duration;
@@ -114,11 +114,12 @@ public Response createAvailabilityMetric(
         Metric<?> metric = new Metric<DataPoint<?>>(new MetricId(tenantId, AVAILABILITY, metricDefinition.getId()),
                 metricDefinition.getTags(), metricDefinition.getDataRetention());
         try {
-            EntityCreatedObserver<MetricAlreadyExistsException> observer = new MetricCreatedObserver(location);
             Observable<Void> observable = metricsService.createMetric(metric);
-            observable.subscribe(observer);
             observable.toBlocking().lastOrDefault(null);
-        return observer.getResponse();
+            return Response.created(location).build();
+        } catch (MetricAlreadyExistsException e) {
+            String message = "A metric with name [" + e.getMetric().getId().getName() + "] already exists";
+            return Response.status(Response.Status.CONFLICT).entity(new ApiError(message)).build();
         } catch (Exception e) {
             return ApiUtils.serverError(e);
         }

api/metrics-api-jaxrs-1.1/src/main/java/org/hawkular/metrics/api/jaxrs/handler/CounterHandler.java

@@ -18,7 +18,9 @@
 
 import static java.util.concurrent.TimeUnit.HOURS;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
 import static javax.ws.rs.core.MediaType.APPLICATION_JSON;
+
 import static org.hawkular.metrics.api.jaxrs.filter.TenantFilter.TENANT_HEADER_NAME;
 import static org.hawkular.metrics.api.jaxrs.util.ApiUtils.requestToCounterDataPoints;
 import static org.hawkular.metrics.api.jaxrs.util.ApiUtils.requestToCounters;
@@ -41,14 +43,13 @@
 import javax.ws.rs.core.UriInfo;
 
 import org.hawkular.metrics.api.jaxrs.ApiError;
-import org.hawkular.metrics.api.jaxrs.handler.observer.EntityCreatedObserver;
-import org.hawkular.metrics.api.jaxrs.handler.observer.MetricCreatedObserver;
 import org.hawkular.metrics.api.jaxrs.model.Counter;
 import org.hawkular.metrics.api.jaxrs.model.CounterDataPoint;
 import org.hawkular.metrics.api.jaxrs.model.GaugeDataPoint;
 import org.hawkular.metrics.api.jaxrs.request.MetricDefinition;
 import org.hawkular.metrics.api.jaxrs.util.ApiUtils;
 import org.hawkular.metrics.core.api.Metric;
+import org.hawkular.metrics.core.api.MetricAlreadyExistsException;
 import org.hawkular.metrics.core.api.MetricId;
 import org.hawkular.metrics.core.api.MetricsService;
 import org.slf4j.Logger;
@@ -105,13 +106,13 @@ public Response createCounter(
         Metric<Double> metric = new Metric<>(new MetricId(tenantId, COUNTER, metricDefinition.getId()),
                 metricDefinition.getTags(), metricDefinition.getDataRetention());
         URI location = uriInfo.getBaseUriBuilder().path("/counters/{id}").build(metric.getId().getName());
-
         try {
-            EntityCreatedObserver<?> observer = new MetricCreatedObserver(location);
             Observable<Void> observable = metricsService.createMetric(metric);
-            observable.subscribe(observer);
             observable.toBlocking().lastOrDefault(null);
-            return observer.getResponse();
+            return Response.created(location).build();
+        } catch (MetricAlreadyExistsException e) {
+            String message = "A metric with name [" + e.getMetric().getId().getName() + "] already exists";
+            return Response.status(Response.Status.CONFLICT).entity(new ApiError(message)).build();
         } catch (Exception e) {
             return ApiUtils.serverError(e);
         }

api/metrics-api-jaxrs-1.1/src/main/java/org/hawkular/metrics/api/jaxrs/handler/GaugeHandler.java

@@ -18,7 +18,9 @@
 
 import static java.util.concurrent.TimeUnit.HOURS;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
 import static javax.ws.rs.core.MediaType.APPLICATION_JSON;
+
 import static org.hawkular.metrics.api.jaxrs.filter.TenantFilter.TENANT_HEADER_NAME;
 import static org.hawkular.metrics.api.jaxrs.util.ApiUtils.badRequest;
 import static org.hawkular.metrics.api.jaxrs.util.ApiUtils.requestToGaugeDataPoints;
@@ -46,8 +48,6 @@
 import javax.ws.rs.core.UriInfo;
 
 import org.hawkular.metrics.api.jaxrs.ApiError;
-import org.hawkular.metrics.api.jaxrs.handler.observer.EntityCreatedObserver;
-import org.hawkular.metrics.api.jaxrs.handler.observer.MetricCreatedObserver;
 import org.hawkular.metrics.api.jaxrs.model.Gauge;
 import org.hawkular.metrics.api.jaxrs.model.GaugeDataPoint;
 import org.hawkular.metrics.api.jaxrs.param.Duration;
@@ -58,6 +58,7 @@
 import org.hawkular.metrics.core.api.BucketedOutput;
 import org.hawkular.metrics.core.api.Buckets;
 import org.hawkular.metrics.core.api.Metric;
+import org.hawkular.metrics.core.api.MetricAlreadyExistsException;
 import org.hawkular.metrics.core.api.MetricId;
 import org.hawkular.metrics.core.api.MetricsService;
 
@@ -107,13 +108,13 @@ public Response createGaugeMetric(
         Metric<Double> metric = new Metric<>(new MetricId(tenantId, GAUGE, metricDefinition.getId()),
                 metricDefinition.getTags(), metricDefinition.getDataRetention());
         URI location = uriInfo.getBaseUriBuilder().path("/gauges/{id}").build(metric.getId().getName());
-
         try {
-            EntityCreatedObserver<?> observer = new MetricCreatedObserver(location);
             Observable<Void> observable = metricsService.createMetric(metric);
-            observable.subscribe(observer);
             observable.toBlocking().lastOrDefault(null);
-            return observer.getResponse();
+            return Response.created(location).build();
+        } catch (MetricAlreadyExistsException e) {
+            String message = "A metric with name [" + e.getMetric().getId().getName() + "] already exists";
+            return Response.status(Response.Status.CONFLICT).entity(new ApiError(message)).build();
         } catch (Exception e) {
             return ApiUtils.serverError(e);
         }

api/metrics-api-jaxrs-1.1/src/main/java/org/hawkular/metrics/api/jaxrs/handler/TenantsHandler.java

@@ -31,12 +31,11 @@
 import javax.ws.rs.core.UriInfo;
 
 import org.hawkular.metrics.api.jaxrs.ApiError;
-import org.hawkular.metrics.api.jaxrs.handler.observer.EntityCreatedObserver;
-import org.hawkular.metrics.api.jaxrs.handler.observer.TenantCreatedObserver;
 import org.hawkular.metrics.api.jaxrs.request.TenantParam;
 import org.hawkular.metrics.api.jaxrs.util.ApiUtils;
 import org.hawkular.metrics.core.api.MetricsService;
 import org.hawkular.metrics.core.api.Tenant;
+import org.hawkular.metrics.core.api.TenantAlreadyExistsException;
 
 import com.wordnik.swagger.annotations.Api;
 import com.wordnik.swagger.annotations.ApiOperation;
@@ -75,15 +74,15 @@ public Response createTenant(@ApiParam(required = true) TenantParam params,
             @Context UriInfo uriInfo
     ) {
         URI location = uriInfo.getBaseUriBuilder().path("/tenants").build();
-        EntityCreatedObserver<?> observer = new TenantCreatedObserver(location);
         try {
             Observable<Void> observable = metricsService.createTenant(new Tenant(params.getId()));
-            observable.subscribe(observer);
             observable.toBlocking().lastOrDefault(null);
-            return observer.getResponse();
+            return Response.created(location).build();
+        } catch (TenantAlreadyExistsException e) {
+            String message = "A tenant with id [" + e.getTenantId() + "] already exists";
+            return Response.status(Response.Status.CONFLICT).entity(new ApiError(message)).build();
         } catch (Exception e) {
-            Response response = observer.getResponse();
-            return response != null ? response : ApiUtils.serverError(e);
+            return ApiUtils.serverError(e);
         }
     }