Add JmxMetricWriter for exporting metric values to MBeans

User can add a @Bean of type JmxMetricWriter and get all values
automatically exported in a form that is usable in jconsole
or jvisualvm.

spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/jmx/DefaultMetricNamingStrategyTests.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2012-2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.actuate.metrics.jmx;
+
+import javax.management.ObjectName;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Dave Syer
+ */
+public class DefaultMetricNamingStrategyTests {
+
+	private DefaultMetricNamingStrategy strategy = new DefaultMetricNamingStrategy();
+
+	@Test
+	public void simpleName() throws Exception {
+		ObjectName name = this.strategy.getObjectName(null,
+				"domain:type=MetricValue,name=foo");
+		assertEquals("domain", name.getDomain());
+		assertEquals("foo", name.getKeyProperty("type"));
+	}
+
+	@Test
+	public void onePeriod() throws Exception {
+		ObjectName name = this.strategy.getObjectName(null,
+				"domain:type=MetricValue,name=foo.bar");
+		assertEquals("domain", name.getDomain());
+		assertEquals("foo", name.getKeyProperty("type"));
+		assertEquals("Wrong name: " + name, "bar", name.getKeyProperty("value"));
+	}
+
+	@Test
+	public void twoPeriods() throws Exception {
+		ObjectName name = this.strategy.getObjectName(null,
+				"domain:type=MetricValue,name=foo.bar.spam");
+		assertEquals("domain", name.getDomain());
+		assertEquals("foo", name.getKeyProperty("type"));
+		assertEquals("Wrong name: " + name, "bar", name.getKeyProperty("name"));
+		assertEquals("Wrong name: " + name, "spam", name.getKeyProperty("value"));
+	}
+
+	@Test
+	public void threePeriods() throws Exception {
+		ObjectName name = this.strategy.getObjectName(null,
+				"domain:type=MetricValue,name=foo.bar.spam.bucket");
+		assertEquals("domain", name.getDomain());
+		assertEquals("foo", name.getKeyProperty("type"));
+		assertEquals("Wrong name: " + name, "bar", name.getKeyProperty("name"));
+		assertEquals("Wrong name: " + name, "spam.bucket", name.getKeyProperty("value"));
+	}
+
+}