Create static object of metrics registry

metrics-interceptor/src/main/java/uk/gov/justice/services/metrics/interceptor/MetricRegistryProducer.java

@@ -10,10 +10,18 @@
 @ApplicationScoped
 public class MetricRegistryProducer {
 
+    private static final MetricRegistry METRICS_REGISTRY = createMetricsRegistry();
+
     @Produces
     public MetricRegistry metricRegistry() {
-        final MetricRegistry metricRegistry = new MetricRegistry();
-        JmxReporter.forRegistry(metricRegistry).inDomain("uk.gov.justice.metrics").build().start();
-        return metricRegistry;
+        return METRICS_REGISTRY;
+    }
+
+    private static MetricRegistry createMetricsRegistry() {
+
+        final MetricRegistry aMetricsRegistry = new MetricRegistry();
+        JmxReporter.forRegistry(aMetricsRegistry).inDomain("uk.gov.justice.metrics").build().start();
+
+        return aMetricsRegistry;
     }
 }

metrics-interceptor/src/test/java/uk/gov/justice/services/metrics/interceptor/MetricRegistryProducerTest.java

@@ -3,15 +3,20 @@
 
 import static org.hamcrest.CoreMatchers.not;
 import static org.hamcrest.CoreMatchers.nullValue;
+import static org.hamcrest.CoreMatchers.sameInstance;
+import static org.hamcrest.core.Is.is;
 import static org.junit.Assert.assertThat;
 
+import com.codahale.metrics.MetricRegistry;
 import org.junit.Test;
 
 public class MetricRegistryProducerTest {
 
     @Test
-    public void shouldProduceRegistry() throws Exception {
-        MetricRegistryProducer producer = new MetricRegistryProducer();
-        assertThat(producer.metricRegistry(), not(nullValue()));
+    public void shouldProduceRegistry() {
+        final MetricRegistryProducer producer = new MetricRegistryProducer();
+        final MetricRegistry actual = producer.metricRegistry();
+        assertThat(actual, not(nullValue()));
+        assertThat(actual, is(sameInstance(producer.metricRegistry())));
     }
 }