[bs-143] Add LiveBeansView to Actuator app on /beans

As per standard LiveBeansView features, if spring.liveBeansView.mbeanDomain
is set in the Environment, then all application contexts are displayed,
otherwise only the local one.  Only JSON is served (via produces=).

[Fixes #50879457]

spring-bootstrap-actuator/src/main/java/org/springframework/bootstrap/actuate/autoconfigure/BeansConfiguration.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2012-2013 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.bootstrap.actuate.autoconfigure;
+
+import javax.servlet.Servlet;
+
+import org.springframework.bootstrap.actuate.endpoint.beans.BeansEndpoint;
+import org.springframework.bootstrap.context.annotation.ConditionalOnClass;
+import org.springframework.bootstrap.context.annotation.ConditionalOnMissingBean;
+import org.springframework.bootstrap.context.annotation.EnableAutoConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.DispatcherServlet;
+
+/**
+ * {@link EnableAutoConfiguration Auto-configuration} for /beans endpoint.
+ * 
+ * @author Dave Syer
+ */
+@Configuration
+@ConditionalOnClass({ Servlet.class, DispatcherServlet.class })
+@ConditionalOnMissingBean({ BeansEndpoint.class })
+public class BeansConfiguration {
+
+	@Bean
+	public BeansEndpoint beansEndpoint() {
+		return new BeansEndpoint();
+	}
+
+}

spring-bootstrap-actuator/src/main/java/org/springframework/bootstrap/actuate/autoconfigure/ManagementEndpointsRegistration.java

@@ -28,7 +28,7 @@ import org.springframework.context.annotation.Import;
 @Configuration
 @ConditionalOnManagementContext
 @Import({ MetricsConfiguration.class, HealthConfiguration.class,
-		ShutdownConfiguration.class, TraceConfiguration.class })
+		ShutdownConfiguration.class, TraceConfiguration.class, BeansConfiguration.class })
 public class ManagementEndpointsRegistration {
 
 }

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

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2012-2013 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.bootstrap.actuate.endpoint.beans;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.beans.BeansException;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextAware;
+import org.springframework.context.support.LiveBeansView;
+import org.springframework.core.env.Environment;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.ResponseBody;
+
+/**
+ * Exposes JSON view of Spring beans. If the {@link Environment} contains a key setting
+ * the {@link LiveBeansView#MBEAN_DOMAIN_PROPERTY_NAME} then all application contexts in
+ * the JVM will be shown (and the corresponding MBeans will be registered per the standard
+ * behaviour of LiveBeansView). Otherwise only the current application context.
+ * 
+ * @author Dave Syer
+ */
+@Controller
+public class BeansEndpoint implements ApplicationContextAware {
+
+	private LiveBeansView liveBeansView = new LiveBeansView();
+
+	@Override
+	public void setApplicationContext(ApplicationContext context) throws BeansException {
+		if (context.getEnvironment()
+				.getProperty(LiveBeansView.MBEAN_DOMAIN_PROPERTY_NAME) == null) {
+			this.liveBeansView.setApplicationContext(context);
+		}
+	}
+
+	@RequestMapping(value = "${endpoints.beans.path:/beans}", produces = "application/json")
+	@ResponseBody
+	public String error(HttpServletRequest request) {
+		return this.liveBeansView.getSnapshotAsJson();
+	}
+}

spring-bootstrap-actuator/src/main/java/org/springframework/bootstrap/actuate/properties/EndpointsProperties.java

@@ -51,6 +51,9 @@ public class EndpointsProperties {
 	@Valid
 	private Endpoint dump = new Endpoint("/dump");
 
+	@Valid
+	private Endpoint beans = new Endpoint("/beans");
+
 	public Endpoint getInfo() {
 		return this.info;
 	}
@@ -79,6 +82,10 @@ public class EndpointsProperties {
 		return this.dump;
 	}
 
+	public Endpoint getBeans() {
+		return this.beans;
+	}
+
 	public static class Endpoint {
 
 		@NotNull