Provide a sensible default resource loader for applications which don't

need the over-engineered per-site-resource-loading system. git-svn-id: https://samskivert.googlecode.com/svn/trunk@1542 6335cc39-0255-0410-8fd6-9bcaacd3b74c
2004-12-10 23:50:26 +00:00
parent 09e1634711
commit 058aa86400
2 changed files with 94 additions and 0 deletions
@@ -234,6 +234,10 @@ public class DispatcherServlet extends VelocityServlet
        if (siteLoader != null) {
            props.setProperty(RuntimeSingleton.RESOURCE_MANAGER_CLASS,
                              SiteResourceManager.class.getName());
+        } else {
+            // otherwise use a servlet context resource loader
+            props.setProperty(RuntimeSingleton.RESOURCE_MANAGER_CLASS,
+                              ServletContextResourceManager.class.getName());
        }

        // wire up our #import directive
@@ -0,0 +1,90 @@
+//
+// $Id: ServletContextResourceManager.java,v 1.6 2004/02/25 13:16:32 mdb Exp $
+//
+// samskivert library - useful routines for java programs
+// Copyright (C) 2001 Michael Bayne
+// 
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.velocity;
+
+import javax.servlet.ServletContext;
+
+import org.apache.velocity.exception.ParseErrorException;
+import org.apache.velocity.exception.ResourceNotFoundException;
+import org.apache.velocity.runtime.RuntimeServices;
+import org.apache.velocity.runtime.resource.Resource;
+import org.apache.velocity.runtime.resource.ResourceFactory;
+import org.apache.velocity.runtime.resource.ResourceManagerImpl;
+import org.apache.velocity.runtime.resource.loader.ResourceLoader;
+
+/**
+ * A resource manager implementation for Velocity that loads resources
+ * from the servlet context.
+ */
+public class ServletContextResourceManager extends ResourceManagerImpl
+{
+    public void initialize (RuntimeServices rsvc)
+        throws Exception
+    {
+        super.initialize(rsvc);
+        rsvc.info("SCRM initializing.");
+
+        // the web framework was kind enough to slip this into the runtime
+        // instance when it started up
+        Application app = (Application)rsvc.getApplicationAttribute(
+            Application.VELOCITY_ATTR_KEY);
+        if (app == null) {
+            rsvc.warn("SCRM: No application was initialized. A user of the " +
+                      "servlet context resource manager must ensure that " +
+                      "an application is instantiated and initialized.");
+        }
+
+        // create our resource loader
+        _contextLoader = new ServletContextResourceLoader(
+            app.getServletContext());
+
+        // for now, turn caching on with the expectation that new
+        // resources of any sort will result in the entire web application
+        // being reloaded and clearing out the cache
+        _contextLoader.setCachingOn(true);
+
+        rsvc.info("SCRM initialization complete.");
+    }
+
+    protected Resource loadResource(
+        Object resourceKey, int resourceType, String encoding)
+        throws ResourceNotFoundException, ParseErrorException, Exception
+    {
+        // create a blank new resource
+        Resource resource =
+            ResourceFactory.getResource(resourceKey, resourceType);
+        resource.setRuntimeServices(rsvc);
+        resource.setKey(resourceKey);
+        resource.setEncoding(encoding);
+
+        resource.setResourceLoader(_contextLoader);
+        resource.process();
+        resource.setLastModified(_contextLoader.getLastModified(resource));
+        resource.setModificationCheckInterval(
+            _contextLoader.getModificationCheckInterval());
+        resource.touch();
+
+        return resource;
+    }
+
+    /** We use this to load default resources. */
+    protected ServletContextResourceLoader _contextLoader;
+}