Merge branch '1.3.x

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/admin/SpringApplicationAdminJmxAutoConfiguration.java

@@ -22,6 +22,7 @@ import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.admin.SpringApplicationAdminMXBean;
 import org.springframework.boot.admin.SpringApplicationAdminMXBeanRegistrar;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration;
 import org.springframework.context.annotation.Bean;
@@ -34,6 +35,7 @@ import org.springframework.jmx.export.MBeanExporter;
  * for internal use only.
  *
  * @author Stephane Nicoll
+ * @author Andy Wilkinson
  * @since 1.3.0
  * @see SpringApplicationAdminMXBean
  */
@@ -65,6 +67,7 @@ public class SpringApplicationAdminJmxAutoConfiguration {
 	}
 
 	@Bean
+	@ConditionalOnMissingBean
 	public SpringApplicationAdminMXBeanRegistrar springApplicationAdminRegistrar()
 			throws MalformedObjectNameException {
 		String jmxName = this.environment.getProperty(JMX_NAME_PROPERTY,

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/admin/SpringApplicationAdminJmxAutoConfigurationTests.java

@@ -30,6 +30,9 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
+import org.springframework.beans.factory.BeanFactoryUtils;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.boot.admin.SpringApplicationAdminMXBeanRegistrar;
 import org.springframework.boot.autoconfigure.jmx.JmxAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.DispatcherServletAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.EmbeddedServletContainerAutoConfiguration;
@@ -47,6 +50,7 @@ import static org.junit.Assert.fail;
  * Tests for {@link SpringApplicationAdminJmxAutoConfiguration}.
  *
  * @author Stephane Nicoll
+ * @author Andy Wilkinson
  */
 public class SpringApplicationAdminJmxAutoConfigurationTests {
 
@@ -130,6 +134,37 @@ public class SpringApplicationAdminJmxAutoConfigurationTests {
 		assertThat(actual).isEqualTo(String.valueOf(expected));
 	}
 
+	@Test
+	public void onlyRegisteredOnceWhenThereIsAChildContext() throws Exception {
+		SpringApplicationBuilder parentBuilder = new SpringApplicationBuilder().web(false)
+				.sources(JmxAutoConfiguration.class,
+						SpringApplicationAdminJmxAutoConfiguration.class);
+		SpringApplicationBuilder childBuilder = parentBuilder
+				.child(JmxAutoConfiguration.class,
+						SpringApplicationAdminJmxAutoConfiguration.class)
+				.web(false);
+		ConfigurableApplicationContext parent = null;
+		ConfigurableApplicationContext child = null;
+
+		try {
+			parent = parentBuilder.run("--" + ENABLE_ADMIN_PROP);
+			child = childBuilder.run("--" + ENABLE_ADMIN_PROP);
+			BeanFactoryUtils.beanOfType(parent.getBeanFactory(),
+					SpringApplicationAdminMXBeanRegistrar.class);
+			this.thrown.expect(NoSuchBeanDefinitionException.class);
+			BeanFactoryUtils.beanOfType(child.getBeanFactory(),
+					SpringApplicationAdminMXBeanRegistrar.class);
+		}
+		finally {
+			if (parent != null) {
+				parent.close();
+			}
+			if (child != null) {
+				child.close();
+			}
+		}
+	}
+
 	private ObjectName createDefaultObjectName() {
 		return createObjectName(DEFAULT_JMX_NAME);
 	}