ContextLoader and FrameworkServlet support "contextId" parameter for custom serialization id

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/FrameworkServlet.java

@@ -20,7 +20,6 @@ import java.io.IOException;
 import java.security.Principal;
 import java.util.ArrayList;
 import java.util.Collections;
-
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -154,6 +153,9 @@ public abstract class FrameworkServlet extends HttpServletBean {
 	/** WebApplicationContext implementation class to create */
 	private Class<?> contextClass = DEFAULT_CONTEXT_CLASS;
 
+	/** WebApplicationContext id to assign */
+	private String contextId;
+
 	/** Namespace for this servlet */
 	private String namespace;
 
@@ -253,6 +255,7 @@ public abstract class FrameworkServlet extends HttpServletBean {
 		this.webApplicationContext = webApplicationContext;
 	}
 
+
 	/**
 	 * Set the name of the ServletContext attribute which should be used to retrieve the
 	 * {@link WebApplicationContext} that this servlet is supposed to use.
@@ -289,6 +292,21 @@ public abstract class FrameworkServlet extends HttpServletBean {
 		return this.contextClass;
 	}
 
+	/**
+	 * Specify a custom WebApplicationContext id,
+	 * to be used as serialization id for the underlying BeanFactory.
+	 */
+	public void setContextId(String contextId) {
+		this.contextId = contextId;
+	}
+
+	/**
+	 * Return the custom WebApplicationContext id, if any.
+	 */
+	public String getContextId() {
+		return this.contextId;
+	}
+
 	/**
 	 * Set a custom namespace for this servlet,
 	 * to be used for building a default context config location.
@@ -574,27 +592,32 @@ public abstract class FrameworkServlet extends HttpServletBean {
 	}
 
 	protected void configureAndRefreshWebApplicationContext(ConfigurableWebApplicationContext wac) {
-
 		if (ObjectUtils.identityToString(wac).equals(wac.getId())) {
 			// The application context id is still set to its original default value
 			// -> assign a more useful id based on available information
-			ServletContext sc = getServletContext();
-			if (sc.getMajorVersion() == 2 && sc.getMinorVersion() < 5) {
-				// Servlet <= 2.4: resort to name specified in web.xml, if any.
-				String servletContextName = sc.getServletContextName();
-				if (servletContextName != null) {
-					wac.setId(ConfigurableWebApplicationContext.APPLICATION_CONTEXT_ID_PREFIX + servletContextName +
-							"." + getServletName());
+			if (this.contextId != null) {
+				wac.setId(this.contextId);
+			}
+			else {
+				// Generate default id...
+				ServletContext sc = getServletContext();
+				if (sc.getMajorVersion() == 2 && sc.getMinorVersion() < 5) {
+					// Servlet <= 2.4: resort to name specified in web.xml, if any.
+					String servletContextName = sc.getServletContextName();
+					if (servletContextName != null) {
+						wac.setId(ConfigurableWebApplicationContext.APPLICATION_CONTEXT_ID_PREFIX + servletContextName +
+								"." + getServletName());
+					}
+					else {
+						wac.setId(ConfigurableWebApplicationContext.APPLICATION_CONTEXT_ID_PREFIX + getServletName());
+					}
 				}
 				else {
-					wac.setId(ConfigurableWebApplicationContext.APPLICATION_CONTEXT_ID_PREFIX + getServletName());
+					// Servlet 2.5's getContextPath available!
+					wac.setId(ConfigurableWebApplicationContext.APPLICATION_CONTEXT_ID_PREFIX +
+							ObjectUtils.getDisplayString(sc.getContextPath()) + "/" + getServletName());
 				}
 			}
-			else {
-				// Servlet 2.5's getContextPath available!
-				wac.setId(ConfigurableWebApplicationContext.APPLICATION_CONTEXT_ID_PREFIX + sc.getContextPath() +
-						"/" + getServletName());
-			}
 		}
 
 		wac.setServletContext(getServletContext());

org.springframework.web/src/main/java/org/springframework/web/context/ContextLoader.java

@@ -23,11 +23,11 @@ import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.concurrent.ConcurrentHashMap;
-
 import javax.servlet.ServletContext;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.factory.access.BeanFactoryLocator;
 import org.springframework.beans.factory.access.BeanFactoryReference;
@@ -91,13 +91,18 @@ import org.springframework.util.StringUtils;
 public class ContextLoader {
 
 	/**
-	 * Config param for the root WebApplicationContext implementation class to
-	 * use: {@value}
+	 * Config param for the root WebApplicationContext implementation class to use: {@value}
 	 * @see #determineContextClass(ServletContext)
 	 * @see #createWebApplicationContext(ServletContext, ApplicationContext)
 	 */
 	public static final String CONTEXT_CLASS_PARAM = "contextClass";
 
+	/**
+	 * Config param for the root WebApplicationContext id,
+	 * to be used as serialization id for the underlying BeanFactory: {@value}
+	 */
+	public static final String CONTEXT_ID_PARAM = "contextId";
+
 	/**
 	 * Config param for which {@link ApplicationContextInitializer} classes to use
 	 * for initializing the web application context: {@value}
@@ -348,21 +353,20 @@ public class ContextLoader {
 		if (ObjectUtils.identityToString(wac).equals(wac.getId())) {
 			// The application context id is still set to its original default value
 			// -> assign a more useful id based on available information
-			if (sc.getMajorVersion() == 2 && sc.getMinorVersion() < 5) {
-				// Servlet <= 2.4: resort to name specified in web.xml, if any.
-				String servletContextName = sc.getServletContextName();
-				wac.setId(ConfigurableWebApplicationContext.APPLICATION_CONTEXT_ID_PREFIX +
-						ObjectUtils.getDisplayString(servletContextName));
+			String idParam = sc.getInitParameter(CONTEXT_ID_PARAM);
+			if (idParam != null) {
+				wac.setId(idParam);
 			}
 			else {
-				// Servlet 2.5's getContextPath available!
-				try {
-					String contextPath = (String) ServletContext.class.getMethod("getContextPath").invoke(sc);
+				// Generate default id...
+				if (sc.getMajorVersion() == 2 && sc.getMinorVersion() < 5) {
+					// Servlet <= 2.4: resort to name specified in web.xml, if any.
 					wac.setId(ConfigurableWebApplicationContext.APPLICATION_CONTEXT_ID_PREFIX +
-							ObjectUtils.getDisplayString(contextPath));
+							ObjectUtils.getDisplayString(sc.getServletContextName()));
 				}
-				catch (Exception ex) {
-					throw new IllegalStateException("Failed to invoke Servlet 2.5 getContextPath method", ex);
+				else {
+					wac.setId(ConfigurableWebApplicationContext.APPLICATION_CONTEXT_ID_PREFIX +
+							ObjectUtils.getDisplayString(sc.getContextPath()));
 				}
 			}
 		}