Introduced beta version of LiveBeansView for STS 3.1

LiveBeansView includes MBean exposure as well as Servlet exposure, with JSON as the initial output format. In order to identify an MBean per application, a new "getApplicationName()" method got introduced on the ApplicationContext interface, returning the Servlet container context path in case of a web application and defaulting to the empty String. MBean exposure can be driven by the "spring.liveBeansView.mbeanDomain" property, e.g. specifying "liveBeansView" as its value, leading to "liveBeansView:application=" or "liveBeansView:application=/myapp" style names for the per-application MBean.

Issue: SPR-9662

spring-context/src/main/java/org/springframework/context/ApplicationContext.java

@@ -63,6 +63,12 @@ public interface ApplicationContext extends EnvironmentCapable, ListableBeanFact
 	 */
 	String getId();
 
+	/**
+	 * Return a name for the deployed application that this context belongs to.
+	 * @return a name for the deployed application, or the empty String by default
+	 */
+	String getApplicationName();
+
 	/**
 	 * Return a friendly name for this context.
 	 * @return a display name for this context (never <code>null</code>)

spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -32,6 +32,7 @@ import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.DisposableBean;
@@ -242,14 +243,14 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 		this.id = id;
 	}
 
-	/**
-	 * Return the unique id of this application context.
-	 * @return the unique id of the context, or <code>null</code> if none
-	 */
 	public String getId() {
 		return this.id;
 	}
 
+	public String getApplicationName() {
+		return "";
+	}
+
 	/**
 	 * Set a friendly name for this context.
 	 * Typically done during initialization of concrete context implementations.
@@ -283,7 +284,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	 */
 	public ConfigurableEnvironment getEnvironment() {
 		if (this.environment == null) {
-			this.environment = this.createEnvironment();
+			this.environment = createEnvironment();
 		}
 		return this.environment;
 	}
@@ -397,7 +398,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 		if (parent != null) {
 			Environment parentEnvironment = parent.getEnvironment();
 			if (parentEnvironment instanceof ConfigurableEnvironment) {
-				this.getEnvironment().merge((ConfigurableEnvironment)parentEnvironment);
+				getEnvironment().merge((ConfigurableEnvironment)parentEnvironment);
 			}
 		}
 	}
@@ -513,7 +514,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 
 		// Validate that all properties marked as required are resolvable
 		// see ConfigurablePropertyResolver#setRequiredProperties
-		this.getEnvironment().validateRequiredProperties();
+		getEnvironment().validateRequiredProperties();
 	}
 
 	/**
@@ -549,7 +550,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 		// Tell the internal bean factory to use the context's class loader etc.
 		beanFactory.setBeanClassLoader(getClassLoader());
 		beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver());
-		beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, this.getEnvironment()));
+		beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));
 
 		// Configure the bean factory with context callbacks.
 		beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
@@ -940,6 +941,9 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 
 		// Publish the final event.
 		publishEvent(new ContextRefreshedEvent(this));
+
+		// Participate in LiveBeansView MBean, if active.
+		LiveBeansView.registerApplicationContext(this);
 	}
 
 	/**
@@ -1033,6 +1037,8 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 				logger.info("Closing " + this);
 			}
 
+			LiveBeansView.unregisterApplicationContext(this);
+
 			try {
 				// Publish shutdown event.
 				publishEvent(new ContextClosedEvent(this));

spring-context/src/main/java/org/springframework/context/support/LiveBeansView.java

@@ -0,0 +1,181 @@
+/*
+ * Copyright 2002-2012 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.context.support;
+
+import java.lang.management.ManagementFactory;
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import javax.management.MBeanServer;
+import javax.management.ObjectName;
+
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextAware;
+import org.springframework.context.ApplicationContextException;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Adapter for live beans view exposure, building a snapshot of current beans
+ * and their dependencies from either a local ApplicationContext (with a
+ * local LiveBeansView bean definition) or all registered ApplicationContexts
+ * (driven by the "spring.liveBeansView.mbean" environment property).
+ *
+ * <p>Note: This feature is still in beta and primarily designed for use with
+ * SpringSource Tool Suite 3.1.
+ *
+ * @author Juergen Hoeller
+ * @since 3.2
+ * @see #getSnapshotAsJson()
+ * @see org.springframework.web.context.support.LiveBeansViewServlet
+ */
+public class LiveBeansView implements LiveBeansViewMBean, ApplicationContextAware {
+
+	public static final String MBEAN_DOMAIN_PROPERTY_NAME = "spring.liveBeansView.mbeanDomain";
+
+	public static final String MBEAN_APPLICATION_KEY = "application";
+
+	private static final Set<ConfigurableApplicationContext> applicationContexts =
+			new LinkedHashSet<ConfigurableApplicationContext>();
+
+	static void registerApplicationContext(ConfigurableApplicationContext applicationContext) {
+		String mbeanDomain = applicationContext.getEnvironment().getProperty(MBEAN_DOMAIN_PROPERTY_NAME);
+		if (mbeanDomain != null) {
+			synchronized (applicationContexts) {
+				if (applicationContexts.isEmpty()) {
+					try {
+						MBeanServer server = ManagementFactory.getPlatformMBeanServer();
+						server.registerMBean(new LiveBeansView(),
+								new ObjectName(mbeanDomain, MBEAN_APPLICATION_KEY, applicationContext.getApplicationName()));
+					}
+					catch (Exception ex) {
+						throw new ApplicationContextException("Failed to register LiveBeansView MBean", ex);
+					}
+				}
+				applicationContexts.add(applicationContext);
+			}
+		}
+	}
+
+	static void unregisterApplicationContext(ConfigurableApplicationContext applicationContext) {
+		synchronized (applicationContexts) {
+			if (applicationContexts.remove(applicationContext) && applicationContexts.isEmpty()) {
+				try {
+					MBeanServer server = ManagementFactory.getPlatformMBeanServer();
+					String mbeanDomain = applicationContext.getEnvironment().getProperty(MBEAN_DOMAIN_PROPERTY_NAME);
+					server.unregisterMBean(new ObjectName(mbeanDomain, MBEAN_APPLICATION_KEY, applicationContext.getApplicationName()));
+				}
+				catch (Exception ex) {
+					throw new ApplicationContextException("Failed to unregister LiveBeansView MBean", ex);
+				}
+			}
+		}
+	}
+
+
+	private ConfigurableApplicationContext applicationContext;
+
+	public void setApplicationContext(ApplicationContext applicationContext) {
+		Assert.isTrue(applicationContext instanceof ConfigurableApplicationContext,
+				"ApplicationContext does not implement ConfigurableApplicationContext");
+		this.applicationContext = (ConfigurableApplicationContext) applicationContext;
+	}
+
+
+	/**
+	 * Generate a JSON snapshot of current beans and their dependencies,
+	 * finding all active ApplicationContexts through {@link #findApplicationContexts()},
+	 * then delegating to {@link #generateJson(java.util.Set)}.
+	 */
+	public String getSnapshotAsJson() {
+		Set<ConfigurableApplicationContext> contexts;
+		if (this.applicationContext != null) {
+			contexts = Collections.singleton(this.applicationContext);
+		}
+		else {
+			contexts = findApplicationContexts();
+		}
+		return generateJson(contexts);
+	}
+
+	/**
+	 * Actually generate a JSON snapshot of the beans in the given ApplicationContexts
+	 * @param contexts the set of ApplicationContexts
+	 * @return the JSON document
+	 */
+	protected String generateJson(Set<ConfigurableApplicationContext> contexts) {
+		StringBuilder result = new StringBuilder();
+		for (ConfigurableApplicationContext context : contexts) {
+			result.append("{\n\"context\": \"").append(context.getId()).append("\"\n");
+			if (context.getParent() != null) {
+				result.append("\"parent\": \"").append(context.getParent().getId()).append("\"\n");
+			}
+			else {
+				result.append("\"parent\": null\n");
+			}
+			ConfigurableListableBeanFactory bf = context.getBeanFactory();
+			String[] beanNames = bf.getBeanDefinitionNames();
+			for (String beanName : beanNames) {
+				BeanDefinition bd = bf.getBeanDefinition(beanName);
+				if (bd.getRole() != BeanDefinition.ROLE_INFRASTRUCTURE &&
+						(!bd.isLazyInit() || bf.containsSingleton(beanName))) {
+					result.append("{\n\"bean\": \"").append(beanName).append("\"\n");
+					String scope = bd.getScope();
+					if (!StringUtils.hasText(scope)) {
+						scope = BeanDefinition.SCOPE_SINGLETON;
+					}
+					result.append("\"scope\": \"").append(scope).append("\"\n");
+					Class beanType = bf.getType(beanName);
+					if (beanType != null) {
+						result.append("\"type\": \"").append(beanType.getName()).append("\"\n");
+					}
+					else {
+						result.append("\"type\": null\n");
+					}
+					result.append("\"resource\": \"").append(bd.getResourceDescription()).append("\"\n");
+					result.append("\"dependencies\": [");
+					String[] dependencies = bf.getDependenciesForBean(beanName);
+					if (dependencies.length > 0) {
+						result.append("\"");
+					}
+					result.append(StringUtils.arrayToDelimitedString(dependencies, "\", \""));
+					if (dependencies.length > 0) {
+						result.append("\"");
+					}
+					result.append("]\n}\n");
+				}
+			}
+			result.append("}");
+		}
+		return result.toString();
+	}
+
+	/**
+	 * Find all applicable ApplicationContexts for the current application.
+	 * <p>Called if no specific ApplicationContext has been set for this LiveBeansView.
+	 * @return the set of ApplicationContexts
+	 */
+	protected Set<ConfigurableApplicationContext> findApplicationContexts() {
+		synchronized (applicationContexts) {
+			return new LinkedHashSet<ConfigurableApplicationContext>(applicationContexts);
+		}
+	}
+
+}

spring-context/src/main/java/org/springframework/context/support/LiveBeansViewMBean.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2002-2012 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.context.support;
+
+/**
+ * MBean operation interface for the {@link LiveBeansView} feature.
+ *
+ * @author Juergen Hoeller
+ * @since 3.2
+ */
+public interface LiveBeansViewMBean {
+
+	/**
+	 * Generate a JSON snapshot of current beans and their dependencies.
+	 */
+	String getSnapshotAsJson();
+
+}

spring-web/src/main/java/org/springframework/web/context/support/AbstractRefreshableWebApplicationContext.java

@@ -109,7 +109,7 @@ public abstract class AbstractRefreshableWebApplicationContext extends AbstractR
 	public void setServletConfig(ServletConfig servletConfig) {
 		this.servletConfig = servletConfig;
 		if (servletConfig != null && this.servletContext == null) {
-			this.setServletContext(servletConfig.getServletContext());
+			setServletContext(servletConfig.getServletContext());
 		}
 	}
 
@@ -133,6 +133,21 @@ public abstract class AbstractRefreshableWebApplicationContext extends AbstractR
 		return super.getConfigLocations();
 	}
 
+	@Override
+	public String getApplicationName() {
+		if (this.servletContext == null) {
+			return "";
+		}
+		if (this.servletContext.getMajorVersion() == 2 && this.servletContext.getMinorVersion() < 5) {
+			String name = this.servletContext.getServletContextName();
+			return (name != null ? name : "");
+		}
+		else {
+			// Servlet 2.5 available
+			return this.servletContext.getContextPath();
+		}
+	}
+
 	/**
 	 * Create and return a new {@link StandardServletEnvironment}. Subclasses may override
 	 * in order to configure the environment or specialize the environment type returned.

spring-web/src/main/java/org/springframework/web/context/support/GenericWebApplicationContext.java

@@ -68,6 +68,7 @@ public class GenericWebApplicationContext extends GenericApplicationContext
 
 	private ThemeSource themeSource;
 
+
 	/**
 	 * Create a new GenericWebApplicationContext.
 	 * @see #setServletContext
@@ -123,6 +124,20 @@ public class GenericWebApplicationContext extends GenericApplicationContext
 		return this.servletContext;
 	}
 
+	@Override
+	public String getApplicationName() {
+		if (this.servletContext == null) {
+			return "";
+		}
+		if (this.servletContext.getMajorVersion() == 2 && this.servletContext.getMinorVersion() < 5) {
+			String name = this.servletContext.getServletContextName();
+			return (name != null ? name : "");
+		}
+		else {
+			// Servlet 2.5 available
+			return this.servletContext.getContextPath();
+		}
+	}
 
 	/**
 	 * Create and return a new {@link StandardServletEnvironment}.

spring-web/src/main/java/org/springframework/web/context/support/LiveBeansViewServlet.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2002-2012 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.web.context.support;
+
+import java.io.IOException;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.springframework.context.support.LiveBeansView;
+
+/**
+ * Servlet variant of {@link LiveBeansView}'s MBean exposure.
+ *
+ * <p>Generates a JSON snapshot for current beans and their dependencies in
+ * all ApplicationContexts that live within the current web application.
+ *
+ * @author Juergen Hoeller
+ * @since 3.2
+ * @see org.springframework.context.support.LiveBeansView#getSnapshotAsJson()
+ */
+public class LiveBeansViewServlet extends HttpServlet {
+
+	private LiveBeansView liveBeansView;
+
+	@Override
+	public void init() throws ServletException {
+		this.liveBeansView = buildLiveBeansView();
+	}
+
+	protected LiveBeansView buildLiveBeansView() {
+		return new ServletContextLiveBeansView(getServletContext());
+	}
+
+	@Override
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		String content = this.liveBeansView.getSnapshotAsJson();
+		response.setContentType("application/json");
+		response.setContentLength(content.length());
+		response.getWriter().write(content);
+	}
+
+}

spring-web/src/main/java/org/springframework/web/context/support/ServletContextLiveBeansView.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2002-2012 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.web.context.support;
+
+import java.util.Enumeration;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import javax.servlet.ServletContext;
+
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.support.LiveBeansView;
+import org.springframework.util.Assert;
+
+/**
+ * {@link LiveBeansView} subclass which looks for all ApplicationContexts
+ * in the web application, as exposed in ServletContext attributes.
+ *
+ * @author Juergen Hoeller
+ * @since 3.2
+ */
+public class ServletContextLiveBeansView extends LiveBeansView {
+
+	private final ServletContext servletContext;
+
+	/**
+	 * Create a new LiveBeansView for the given ServletContext.
+	 * @param servletContext current ServletContext
+	 */
+	public ServletContextLiveBeansView(ServletContext servletContext) {
+		Assert.notNull(servletContext, "ServletContext must not be null");
+		this.servletContext = servletContext;
+	}
+
+	@Override
+	protected Set<ConfigurableApplicationContext> findApplicationContexts() {
+		Set<ConfigurableApplicationContext> contexts = new LinkedHashSet<ConfigurableApplicationContext>();
+		Enumeration<String> attrNames = this.servletContext.getAttributeNames();
+		while (attrNames.hasMoreElements()) {
+			String attrName = attrNames.nextElement();
+			Object attrValue = this.servletContext.getAttribute(attrName);
+			if (attrValue instanceof ConfigurableApplicationContext) {
+				contexts.add((ConfigurableApplicationContext) attrValue);
+			}
+		}
+		return contexts;
+	}
+
+}

spring-webmvc-portlet/src/main/java/org/springframework/web/portlet/context/AbstractRefreshablePortletApplicationContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -143,6 +143,22 @@ public abstract class AbstractRefreshablePortletApplicationContext extends Abstr
 		return super.getConfigLocations();
 	}
 
+	@Override
+	public String getApplicationName() {
+		if (this.portletContext == null) {
+			return "";
+		}
+		String name = this.portletContext.getPortletContextName();
+		return (name != null ? name : "");
+	}
+
+	/**
+	 * Create and return a new {@link StandardPortletEnvironment}.
+	 */
+	@Override
+	protected ConfigurableEnvironment createEnvironment() {
+		return new StandardPortletEnvironment();
+	}
 
 	/**
 	 * Register request/session scopes, a {@link PortletContextAwareProcessor}, etc.
@@ -160,14 +176,6 @@ public abstract class AbstractRefreshablePortletApplicationContext extends Abstr
 				beanFactory, this.servletContext, this.portletContext, this.portletConfig);
 	}
 
-	/**
-	 * Create and return a new {@link StandardPortletEnvironment}.
-	 */
-	@Override
-	protected ConfigurableEnvironment createEnvironment() {
-		return new StandardPortletEnvironment();
-	}
-
 	/**
 	 * This implementation supports file paths beneath the root of the PortletContext.
 	 * @see PortletContextResource
@@ -190,4 +198,5 @@ public abstract class AbstractRefreshablePortletApplicationContext extends Abstr
 	protected void customizeBeanFactory(DefaultListableBeanFactory beanFactory) {
 		super.customizeBeanFactory(beanFactory);
 	}
+
 }