Add documentation for SpringApplicationAdminMXBean

Closes gh-3179

spring-boot-autoconfigure/src/main/resources/META-INF/additional-spring-configuration-metadata.json

@@ -17,6 +17,18 @@
     "description": "Whether subclass-based (CGLIB) proxies are to be created (true) as opposed to standard Java interface-based proxies (false).",
     "defaultValue": false
   },
+  {
+    "name": "spring.application.admin.enabled",
+    "type": "java.lang.Boolean",
+    "description": "Enable admin features for the application.",
+    "defaultValue": false
+  },
+  {
+    "name": "spring.application.admin.jmx-name",
+    "type": "java.lang.String",
+    "description": "JMX name of the application admin MBean.",
+    "defaultValue": "org.springframework.boot:type=Admin,name=SpringApplication"
+  },
   {
     "name": "spring.batch.job.enabled",
     "type": "java.lang.Boolean",

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -45,6 +45,10 @@ content into your application; rather pick only the properties that you need.
 	spring.main.show-banner=true
 	spring.main....= # see class for all properties
 
+	# ADMIN ({sc-spring-boot-autoconfigure}/admin/SpringApplicationAdminJmxAutoConfiguration.{sc-ext}[SpringApplicationAdminJmxAutoConfiguration])
+	spring.application.admin.enabled=false # enable admin features for the application
+	spring.application.admin.jmx-name=org.springframework.boot:type=Admin,name=SpringApplication # JMX name of the application admin MBean
+
 	# OUTPUT
 	spring.output.ansi.enabled=detect # Configure the ANSI output ("detect", "always", "never")
 

spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -218,6 +218,16 @@ be used.
 In addition, beans may implement the `org.springframework.boot.ExitCodeGenerator`
 interface if they wish to return a specific exit code when the application ends.
 
+[[boot-features-application-admin]]
+=== Admin features
+It is possible to enable admin-related features for the application by specifying the
+`spring.application.admin.enabled` property. For now, this exposes the
+{sc-spring-boot}/admin/SpringApplicationAdminMXBean.{sc-ext}[`SpringApplicationAdminMXBean`]`
+on the platform `MBeanServer`. You could use this feature to administer your Spring Boot
+application remotely. This could also be useful for any service wrapper implementation.
+
+NOTE: Be careful when enabling this feature as the MBean exposes a method to shutdown the
+application.
 
 
 [[boot-features-external-config]]