Fall back to standard LiveBeansView behaviour when MBean is in use

Closes gh-8146

Author: wilkinsona

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/BeansEndpoint.java

@@ -75,6 +75,9 @@ private void setLeafContext(ApplicationContext leafContext) {
 
 		@Override
 		public String getSnapshotAsJson() {
+			if (this.leafContext == null) {
+				return super.getSnapshotAsJson();
+			}
 			return generateJson(getContextHierarchy());
 		}
 

spring-boot-samples/spring-boot-sample-actuator/pom.xml

@@ -27,10 +27,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
-		<dependency>
+		<!-- <dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-security</artifactId>
-		</dependency>
+		</dependency> -->
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-jdbc</artifactId>