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-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;
+	}
+
+}