Clarify behavior of JMX in @SpringBootTest

Closes gh-13008

spring-boot-docs/src/test/java/org/springframework/boot/jmx/SampleApp.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2012-2018 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.jmx;
+
+import org.springframework.boot.SpringBootConfiguration;
+import org.springframework.boot.autoconfigure.ImportAutoConfiguration;
+import org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration;
+
+/**
+ * A sample {@link SpringBootConfiguration} that only enables JMX auto-configuration.
+ *
+ * @author Stephane Nicoll
+ */
+@SpringBootConfiguration
+@ImportAutoConfiguration(JmxAutoConfiguration.class)
+public class SampleApp {
+
+}

spring-boot-docs/src/test/java/org/springframework/boot/jmx/SampleJmxTests.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2012-2018 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.jmx;
+
+import javax.management.MBeanServer;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.junit4.SpringRunner;
+
+/**
+ * Example integration test that uses JMX.
+ *
+ * @author Stephane Nicoll
+ */
+// tag::test[]
+@RunWith(SpringRunner.class)
+@SpringBootTest(properties = "spring.jmx.enabled=true")
+@DirtiesContext
+public class SampleJmxTests {
+
+	@Autowired
+	private MBeanServer mBeanServer;
+
+	@Test
+	public void exampleTest() {
+		// ...
+
+	}
+
+}
+// end::test[]