Many changes to provide site-specific resource loading (we're almost

there) and to bring things up to date with some Velocity changes Geir made
at my prompting.


git-svn-id: https://samskivert.googlecode.com/svn/trunk@428 6335cc39-0255-0410-8fd6-9bcaacd3b74c

projects/samskivert/src/java/com/samskivert/velocity/Application.java

@@ -1,5 +1,5 @@
 //
-// $Id: Application.java,v 1.4 2001/11/02 00:58:22 mdb Exp $
+// $Id: Application.java,v 1.5 2001/11/06 04:49:32 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -38,10 +38,63 @@ import com.samskivert.util.StringUtil;
 public class Application
 {
     /**
-     * This should be overridden by the application implementation to
+     * Performs initializations common to all applications. Applications
-     * perform any necessary initialization.
+     * should override {@link #willInit} to perform initializations that
+     * need to take place before the common initialization (which includes
+     * the creation of the site identifier and message manager) and should
+     * override {@link #didInit} to perform initializations that need to
+     * take place after the common initialization (like passing the
+     * application to entities that might turn around and request a
+     * reference to our site identifier).
+     *
+     * @param context the servlet context in which this application is
+     * operating.
+     * @param logicPkg the base package for all of the logic
+     * implementations for this application.
      */
-    public void init (ServletContext context)
+    public void init (ServletContext context, String logicPkg)
+    {
+        // keep this around for later
+        _context = context;
+
+        // let the derived application do pre-init stuff
+        willInit();
+
+        // remove any trailing dot
+        if (logicPkg.endsWith(".")) {
+            _logicPkg = logicPkg.substring(0, logicPkg.length()-1);
+        } else {
+            _logicPkg = logicPkg;
+        }
+
+        // instantiate our message manager if the application wants one
+        String bpath = getMessageBundlePath();
+        if (bpath != null) {
+            _msgmgr = new MessageManager(bpath);
+        }
+
+        // create our site identifier
+        _siteIdent = createSiteIdentifier(_context);
+
+        // let the derived application do post-init stuff
+        didInit();
+    }
+
+    /**
+     * This should be overridden by the application implementation to
+     * invoke any necessary pre-initialization code. They should be sure
+     * to call <code>super.willInit()</code>.
+     */
+    protected void willInit ()
+    {
+    }
+
+    /**
+     * This should be overridden by the application implementation to
+     * invoke any necessary post-initialization code. They should be sure
+     * to call <code>super.didInit()</code>.
+     */
+    protected void didInit ()
     {
     }
 
@@ -53,6 +106,15 @@ public class Application
     {
     }
 
+    /**
+     * Returns a reference to the servlet context in which this
+     * application is operating.
+     */
+    public ServletContext getServletContext ()
+    {
+        return _context;
+    }
+
     /**
      * Returns the message manager in effect for this application, if one
      * is in effect.
@@ -144,34 +206,6 @@ public class Application
         return _msgmgr.getMessage(ctx.getRequest(), msg, args);
     }
 
-    /**
-     * Performs initializations common to all applications. We could put
-     * this in {@link #init} and require application derived classes to
-     * call <code>super.init()</code> but we want it to happen after the
-     * application initializes itself.
-     *
-     * @param logicPkg the base package for all of the logic
-     * implementations for this application.
-     */
-    protected void postInit (ServletContext ctx, String logicPkg)
-    {
-        // remove any trailing dot
-        if (logicPkg.endsWith(".")) {
-            _logicPkg = logicPkg.substring(0, logicPkg.length()-1);
-        } else {
-            _logicPkg = logicPkg;
-        }
-
-        // instantiate our message manager if the application wants one
-        String bpath = getMessageBundlePath();
-        if (bpath != null) {
-            _msgmgr = new MessageManager(bpath);
-        }
-
-        // create our site identifier
-        _siteIdent = createSiteIdentifier(ctx);
-    }
-
     /**
      * Given the servlet path (the part of the URI after the context path)
      * this generates the classname of the logic class that should handle
@@ -190,6 +224,10 @@ public class Application
         return _logicPkg + path;
     }
 
+    /** A reference to the servlet context in which this application is
+     * operating. */
+    protected ServletContext _context;
+
     /** The prefix that we use to generate fully qualified logic class
      * names. */
     protected String _logicPkg;

projects/samskivert/src/java/com/samskivert/velocity/DispatcherServlet.java

@@ -1,5 +1,5 @@
 //
-// $Id: DispatcherServlet.java,v 1.8 2001/11/02 18:46:48 mdb Exp $
+// $Id: DispatcherServlet.java,v 1.9 2001/11/06 04:49:32 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -35,12 +35,14 @@ import org.apache.velocity.app.Velocity;
 import org.apache.velocity.context.Context;
 import org.apache.velocity.exception.ParseErrorException;
 import org.apache.velocity.exception.ResourceNotFoundException;
+import org.apache.velocity.runtime.RuntimeSingleton;
 import org.apache.velocity.servlet.VelocityServlet;
 
 import com.samskivert.Log;
 
 import com.samskivert.servlet.MessageManager;
 import com.samskivert.servlet.RedirectException;
+import com.samskivert.servlet.SiteIdentifier;
 import com.samskivert.servlet.util.ExceptionMap;
 import com.samskivert.servlet.util.FriendlyException;
 
@@ -162,16 +164,13 @@ public class DispatcherServlet extends VelocityServlet
     /**
      * Initialize ourselves and our application.
      */
-    public void init (ServletConfig config)
+    protected void initVelocity (ServletConfig config)
-        throws ServletException
+         throws ServletException
     {
-        super.init(config);
-
-        // Log.info("Initializing dispatcher servlet.");
-
         // load up our application configuration
         try {
             String appcl = config.getInitParameter(APP_CLASS_PROPS_KEY);
+            Log.info("Creating application [class=" + appcl + "].");
             if (appcl == null) {
                 _app = new Application();
             } else {
@@ -184,21 +183,17 @@ public class DispatcherServlet extends VelocityServlet
             if (StringUtil.blank(logicPkg)) {
                 logicPkg = "";
             }
-            _app.init(getServletContext());
+            _app.init(getServletContext(), logicPkg);
-            _app.postInit(getServletContext(), logicPkg);
 
         } catch (Throwable t) {
             Log.warning("Error instantiating application.");
             Log.logStackTrace(t);
         }
-    }
 
-    // documentation inherited
+        // stick the application into the Velocity application context
-    protected void initVelocity (ServletConfig config)
+        Velocity.setApplicationContext(_app);
-         throws ServletException
+
-    {
+        // now let velocity initialize itself
-        // stick the servlet context into the Velocity application context
-        Velocity.setApplicationContext(getServletContext());
         super.initVelocity(config);
     }
 
@@ -219,13 +214,20 @@ public class DispatcherServlet extends VelocityServlet
      */
     public Template handleRequest (HttpServletRequest req,
                                    HttpServletResponse rsp,
-                                   Context ctx) throws Exception
+                                   Context ctx)
+        throws Exception
     {
         InvocationContext ictx = (InvocationContext)ctx;
         String errmsg = null;
 
-	// first we select the template
+        // obtain the siteid for this request and stuff that into the
-	Template tmpl = selectTemplate(ictx);
+        // context
+        SiteIdentifier ident = _app.getSiteIdentifier();
+        int siteId = ident.identifySite(req);
+        ctx.put("__siteid__", new Integer(siteId));
+
+	// then select the template
+	Template tmpl = selectTemplate(siteId, ictx);
 
 	// assume an HTML response unless otherwise massaged by the logic
 	rsp.setContentType("text/html");
@@ -313,12 +315,16 @@ public class DispatcherServlet extends VelocityServlet
      *
      * @return The template to be used in generating the response.
      */
-    protected Template selectTemplate (InvocationContext ctx)
+    protected Template selectTemplate (int siteId, InvocationContext ctx)
         throws ResourceNotFoundException, ParseErrorException, Exception
     {
+        // create a site resource key based on the template path and the
+        // id of the site through which this request was made
         String path = ctx.getRequest().getServletPath();
-	// Log.info("Loading template [path=" + path + "].");
+        SiteResourceKey key = new SiteResourceKey(siteId, path);
-        return getTemplate(path);
+
+	// Log.info("Loading template [key=" + key + "].");
+        return RuntimeSingleton.getRuntimeServices().getTemplate(key);
     }
 
     /**

projects/samskivert/src/java/com/samskivert/velocity/ImportDirective.java

@@ -0,0 +1,170 @@
+//
+// $Id: ImportDirective.java,v 1.1 2001/11/06 04:49:32 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 java.io.IOException;
+import java.io.Writer;
+
+import org.apache.velocity.context.InternalContextAdapter;
+
+import org.apache.velocity.Template;
+import org.apache.velocity.runtime.RuntimeConstants;
+import org.apache.velocity.runtime.directive.Directive;
+import org.apache.velocity.runtime.parser.node.Node;
+import org.apache.velocity.runtime.parser.node.SimpleNode;
+import org.apache.velocity.runtime.resource.Resource;
+
+import org.apache.velocity.exception.MethodInvocationException;
+import org.apache.velocity.exception.ParseErrorException;
+import org.apache.velocity.exception.ResourceNotFoundException;
+
+import com.samskivert.servlet.SiteIdentifier;
+import com.samskivert.util.StringUtil;
+
+/**
+ * Pluggable directive that handles the #import() statement in VTL. Import
+ * is like #parse() except that it creates a {@link SiteResourceKey} based
+ * on information from the current request when fetching the imported
+ * template.
+ */
+public class ImportDirective extends Directive
+{
+    /**
+     * Returns name of this directive.
+     */
+    public String getName ()
+    {
+        return "import";
+    }        
+    
+    /**
+     * Return type of this directive.
+     */
+    public int getType ()
+    {
+        return LINE;
+    }        
+    
+    /**
+     * Loads and renders the imported template.
+     */
+    public boolean render (
+        InternalContextAdapter context, Writer writer, Node node)
+        throws IOException, ResourceNotFoundException, ParseErrorException,
+               MethodInvocationException
+    {
+        // make sure an argument was supplied to the directive
+        if (node.jjtGetChild(0) == null) {
+            rsvc.error("#import() error :  null argument");
+            return false;
+        }
+
+        // make sure that argument has a value
+        Object value = node.jjtGetChild(0).value(context);
+        if (value == null) {
+            rsvc.error("#import() error :  null argument");
+            return false;
+        }
+
+        // obtain the path to the desired template
+        String path = value.toString();
+
+        // make sure we haven't exceeded the configured parse depth
+        Object[] templateStack = context.getTemplateNameStack();
+        int maxlen = rsvc.getInt(
+            RuntimeConstants.PARSE_DIRECTIVE_MAXDEPTH, 20);
+        if (templateStack.length >= maxlen) {
+            rsvc.error("Max recursion depth reached (" + maxlen + "). "  +
+                       "File stack: " +
+                       StringUtil.toString(templateStack) + ".");
+            return false;
+        }
+
+        // inherit the current encoding if there is a current template,
+        // otherwise use the configured encoding
+        String encoding = null;
+        Resource current = context.getCurrentResource();
+        if (current != null) {
+            encoding = current.getEncoding();
+        } else {
+            encoding = (String)
+                rsvc.getProperty(RuntimeConstants.INPUT_ENCODING);
+        }
+
+        // construct the template key based on the desired path and the
+        // site information in the current context. the siteid was shoved
+        // into the context by the dispatcher servlet. this is a hack, i
+        // know, but i couldn't convince the velocity peeps that we should
+        // have access to a request context in places like this
+        Object siteIdVal = context.get("__siteid__");
+        int siteId = SiteIdentifier.DEFAULT_SITE_ID;
+        try {
+            siteId = ((Integer)siteIdVal).intValue();
+        } catch (Exception e) {
+            rsvc.error("#import() error: No siteId information in context.");
+        }
+        Object tkey = new SiteResourceKey(siteId, path);
+
+        // locate the requested template
+        Template t = null;
+        try {
+            t = rsvc.getTemplate(tkey, encoding);   
+
+        } catch (ResourceNotFoundException rnfe) {
+            rsvc.error("#import(): cannot find template '" + tkey +
+                       "', called from template " +
+                       context.getCurrentTemplateName() +
+                       " at (" + getLine() + ", " + getColumn() + ")");       	
+            throw rnfe;
+
+        } catch (ParseErrorException pee) {
+            rsvc.error("#import(): syntax error in #import()-ed template '" +
+                       tkey + "', called from template " +
+                       context.getCurrentTemplateName() +
+                       " at (" + getLine() + ", " + getColumn() + ")");    
+            throw pee;
+
+        } catch (Exception e) {	
+            rsvc.error("#import(): Error [path=" + tkey +
+                       ", error=" + e + "].");
+            return false;
+        }
+
+        // finally render the template
+        try {
+            context.pushCurrentTemplateName(path);
+            ((SimpleNode)t.getData()).render(context, writer);
+
+        } catch (Exception e) {        
+            // we want to pass method invocation exceptions through
+            if (e instanceof MethodInvocationException) {
+                throw (MethodInvocationException)e;
+            }
+            rsvc.error("Exception rendering #import(" + path + "): " + e);
+            return false;
+
+        } finally {
+            context.popCurrentTemplateName();
+        }
+
+        return true;
+    }
+}

projects/samskivert/src/java/com/samskivert/velocity/ServletContextResourceLoader.java

@@ -1,5 +1,5 @@
 //
-// $Id: ServletContextResourceLoader.java,v 1.2 2001/11/02 02:30:24 mdb Exp $
+// $Id: ServletContextResourceLoader.java,v 1.3 2001/11/06 04:49:32 mdb Exp $
 //
 // samskivert library - useful routines for java programs
 // Copyright (C) 2001 Michael Bayne
@@ -38,6 +38,24 @@ import org.apache.velocity.runtime.resource.loader.ResourceLoader;
  */
 public class ServletContextResourceLoader extends ResourceLoader
 {
+    /**
+     * When used with the default Velocity resource manager, we are
+     * constructed with our zero-argument constructor and later
+     * initialized via {@link #init}.
+     */
+    public ServletContextResourceLoader ()
+    {
+    }
+
+    /**
+     * When used with the {@link SiteResourceManager} we are constructed
+     * with our servlet context reference and not later initialized.
+     */
+    public ServletContextResourceLoader (ServletContext sctx)
+    {
+        _sctx = sctx;
+    }
+
     /**
      * Called by Velocity to initialize this resource loader.
      */

projects/samskivert/src/java/com/samskivert/velocity/SiteJarResourceLoader.java

@@ -0,0 +1,182 @@
+//
+// $Id: SiteJarResourceLoader.java,v 1.1 2001/11/06 04:49:32 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 java.io.InputStream;
+import java.io.IOException;
+import javax.servlet.ServletContext;
+
+import org.apache.commons.collections.ExtendedProperties;
+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.loader.ResourceLoader;
+
+import com.samskivert.Log;
+import com.samskivert.servlet.SiteIdentifier;
+
+/**
+ * A Velocity resource loader that loads resources from site-specific jar
+ * files. This cannot be used with the default Velocity resource manager,
+ * but is used by the {@link SiteResourceManager} which automatically
+ * handles the creation and use of this resource loader.
+ *
+ * @see com.samskivert.servlet.SiteResourceLoader
+ */
+public class SiteResourceLoader extends ResourceLoader
+{
+    /**
+     * Constructs a site resource loader that will use the specified site
+     * identifier to map site ids to site strings.
+     */
+    public SiteResourceLoader (SiteIdentifier ident, ServletContext context)
+    {
+        // naming conflict... alas.
+        _loader = new com.samskivert.servlet.SiteResourceLoader(
+            ident, context);
+    }
+
+    /**
+     * This is not called.
+     */
+    public void init (ExtendedProperties config)
+    {
+    }
+
+    /**
+     * Returns the input stream that can be used to load the named
+     * resource.
+     *
+     * @param resourceKey the locator key for the resource to be loaded.
+     *
+     * @return an input stream that can be used to read the resource.
+     *
+     * @exception ResourceNotFoundException if the resource was not found.
+     */
+    public InputStream getResourceStream (Object resourceKey)
+        throws ResourceNotFoundException
+    {
+        SiteResourceKey skey = castKey(resourceKey);
+        if (skey == null) {
+            String errmsg = "Cannot use SiteResourceLoader without " +
+                "loading resources with SiteResourceKey instances.";
+            throw new ResourceNotFoundException(errmsg);
+        }
+
+        // load it on up
+        try {
+            InputStream stream = _loader.getResourceAsStream(
+                skey.getSiteId(), skey.getPath(), false);
+            if (stream == null) {
+                String errmsg = "Unable to load resource via " +
+                    "site-specific jar file [key=" + skey + "].";
+                throw new ResourceNotFoundException(errmsg);
+            }
+            return stream;
+
+        } catch (IOException ioe) {
+            throw new ResourceNotFoundException(ioe.getMessage());
+        }
+    }
+    
+    /**
+     * Things won't ever be modified when loaded from the servlet context
+     * because they came from the webapp .war file and if that is
+     * reloaded, everything will be thrown away and started afresh.
+     */
+    public boolean isSourceModified (Resource resource)
+    {
+        SiteResourceKey skey = castKey(resource.getKey());
+        if (skey == null) {
+            // return false if we were supplied with a bogus key
+            return false;
+        }
+
+        // if the resource is for the default site, it is never considered
+        // to be modified
+        int siteId = skey.getSiteId();
+        if (siteId == SiteIdentifier.DEFAULT_SITE_ID) {
+            return false;
+
+        } else {
+            // otherwise compare the last modified time of the loaded
+            // resource with the last modified time of the associated
+            // site-specific jar file
+            try {
+                return (resource.getLastModified() <
+                        _loader.getLastModified(siteId));
+            } catch (IOException ioe) {
+                Log.warning("Failure obtaining last modified time of " +
+                            "site-specific jar file [siteId=" + siteId +
+                            ", error=" + ioe + "].");
+                return false;
+            }
+        }
+    }
+
+    /**
+     * Things won't ever be modified when loaded from the servlet context
+     * because they came from the webapp .war file and if that is
+     * reloaded, everything will be thrown away and started afresh. So we
+     * can punt here and return zero.
+     */
+    public long getLastModified (Resource resource)
+    {
+        SiteResourceKey skey = castKey(resource.getKey());
+        if (skey == null) {
+            // return 0 if we were supplied with a bogus key
+            return 0;
+        }
+
+        // if the resource is for the default site, it is never considered
+        // to be modified
+        int siteId = skey.getSiteId();
+        if (siteId == SiteIdentifier.DEFAULT_SITE_ID) {
+            return 0;
+
+        } else {
+            // otherwise return the last modified time of the associated
+            // site-specific jar file
+            try {
+                return _loader.getLastModified(siteId);
+            } catch (IOException ioe) {
+                Log.warning("Failure obtaining last modified time of " +
+                            "site-specific jar file [siteId=" + siteId +
+                            ", error=" + ioe + "].");
+                return 0;
+            }
+        }
+    }
+
+    /**
+     * Casts the supplied resource key to a {@link SiteResourceKey} and
+     * returns it iff it is an instance of such. Returns null otherwise.
+     */
+    protected SiteResourceKey castKey (Object resourceKey)
+    {
+        return (resourceKey instanceof SiteResourceKey) ?
+            (SiteResourceKey)resourceKey : null;
+    }
+
+    /** A reference to the site resource loader through which we'll load
+     * things. */
+    protected com.samskivert.servlet.SiteResourceLoader _loader;
+}

projects/samskivert/src/java/com/samskivert/velocity/SiteResourceKey.java

@@ -0,0 +1,180 @@
+//
+// $Id: SiteResourceKey.java,v 1.1 2001/11/06 04:49:32 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 com.samskivert.servlet.SiteIdentifier;
+import com.samskivert.util.IntListUtil;
+import com.samskivert.util.StringUtil;
+
+/**
+ * The site resource key is used as a key for resources that can be used
+ * for one or more sites. A resource always has the same path, but can be
+ * valid for a single site, or multiple sites and the set of sites for
+ * which a resource is valid can change without impacting the key's hash
+ * value.
+ */
+public class SiteResourceKey
+{
+    /**
+     * Constructs a new site resource key for the specified resource,
+     * loaded via the specified site.
+     */
+    public SiteResourceKey (int siteId, String path)
+    {
+        _path = path;
+        _sites = new int[] { siteId };
+    }
+
+    /**
+     * Resource keys that contain only a single site id will return that
+     * site id as their primary. Those that contain multiple sites are
+     * assumed to reference default resources (which may be applicable to
+     * multiple sites) in which case the default site id is returned.
+     */
+    public int getSiteId ()
+    {
+        return (_sites.length == 1 ? _sites[0] :
+                SiteIdentifier.DEFAULT_SITE_ID);
+    }
+
+    /**
+     * Returns the path to the resource referenced by this site resource
+     * key.
+     */
+    public String getPath ()
+    {
+        return _path;
+    }
+
+    /**
+     * Returns true if this resource key contains the specified site in
+     * its site set.
+     */
+    public boolean containsSite (int siteId)
+    {
+        return IntListUtil.contains(_sites, siteId);
+    }
+
+    /**
+     * Adds a site to this site resource key. The resource to which this
+     * key maps is assumed to be valid for the added site.
+     */
+    public void addSite (int siteId)
+    {
+        // sanity check
+        if (siteId == 0) {
+            throw new IllegalArgumentException(
+                "Site IDs cannot have the value 0.");
+        }
+
+        // add the site to the list only if it's not already there
+        int[] sites = IntListUtil.testAndAdd(_sites, siteId);
+        if (sites != null) {
+            _sites = sites;
+        }
+    }
+
+    /**
+     * Removes a site from this site resource key. The resource to which
+     * this key maps is no longer assumed to be valid for the removed
+     * site.
+     */
+    public boolean removeSite (int siteId)
+    {
+        // sanity check
+        if (siteId == 0) {
+            throw new IllegalArgumentException(
+                "Site IDs cannot have the value 0.");
+        }
+
+        // remove the site from the list
+        return (IntListUtil.remove(_sites, siteId) != 0);
+    }
+
+    /**
+     * We hash to the hash value of our path.
+     */
+    public int hashCode ()
+    {
+        return _path.hashCode();
+    }
+
+    /**
+     * Two site resource keys are equal if the paths are the same and at
+     * least one site id overlaps between the two keys. Most equality
+     * comparisons will involve one multi-site key and one key that
+     * contains only a single site.
+     */
+    public boolean equals (Object other)
+    {
+        if (other instanceof SiteResourceKey) {
+            SiteResourceKey okey = (SiteResourceKey)other;
+
+            // make sure the paths match
+            if (!_path.equals(okey._path)) {
+                return false;
+            }
+
+            // select the key with fewer sites in its sites array to be in
+            // the outer loop
+            int[] s1 = _sites;
+            int[] s2 = okey._sites;
+            if (s2.length < s1.length) {
+                s1 = s2;
+                s2 = _sites;
+            }
+
+            for (int i1 = 0; i1 < s1.length; i1++) {
+                for (int i2 = 0; i2 < s2.length; i2++) {
+                    if (s1[i1] == s2[i2]) {
+                        return true;
+                    }
+                }
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * The string representation of a resource key is just the path so
+     * that it is backwards compatible with older resource loaders.
+     */
+    public String toString ()
+    {
+        return _path;
+    }
+
+    /**
+     * Returns a string description of this object.
+     */
+    public String description ()
+    {
+        return ("[path=" + _path +
+                ", sites=" + StringUtil.toString(_sites) + "]");
+    }
+
+    /** The path to the resource. */
+    protected String _path;
+
+    /** The sites for which this resource is valid. */
+    protected int[] _sites;
+}

projects/samskivert/src/java/com/samskivert/velocity/SiteResourceManager.java

@@ -0,0 +1,137 @@
+//
+// $Id: SiteResourceManager.java,v 1.1 2001/11/06 04:49:32 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;
+
+import com.samskivert.Log;
+import com.samskivert.servlet.SiteIdentifier;
+
+/**
+ * A resource manager implementation for Velocity that first loads site
+ * specific resources (via the {@link SiteResourceLoader}), but falls back
+ * to default resources if no site-specific resource loader is available.
+ *
+ * <p> If this resource manager is to be used, resources must be fetched
+ * using {@likn SiteResourceKey} objects as keys rather than simple
+ * strings.
+ */
+public class SiteResourceManager extends ResourceManagerImpl
+{
+    public void initialize (RuntimeServices rsvc)
+        throws Exception
+    {
+        super.initialize(rsvc);
+
+        // the web framework was kind enough to slip this into the runtime
+        // instance when it started up
+        Application app = (Application)rsvc.getApplicationContext();
+        if (app == null) {
+            rsvc.warn("SiteResourceManager: Application reference " +
+                      "was not supplied as application context. A " +
+                      "user of the site resource manager must supply " +
+                      "a reference to the Application instance via " +
+                      "Velocity.setApplicationContext().");
+        }
+
+        // get handles on the good stuff
+        _sctx = app.getServletContext();
+        _ident = app.getSiteIdentifier();
+
+        // create our resource loaders
+        _siteLoader = new SiteResourceLoader(_ident, _sctx);
+        _contextLoader = new ServletContextResourceLoader(_sctx);
+    }
+
+    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);
+
+        // if the resource was requested using a site resource key, we can
+        // attempt to load a site-specific version
+        if (resourceKey instanceof SiteResourceKey) {
+            SiteResourceKey rkey = (SiteResourceKey)resourceKey;
+            Log.info("Looking for site-specific version of " +
+                     rkey.description() + ".");
+
+            // make sure the site we're loading for is not the default
+            // site, in which case we want to skip to the second resource
+            // loader directly
+            if (rkey.getSiteId() != SiteIdentifier.DEFAULT_SITE_ID) {
+                // try loading it via the site-specific resource loader
+                try {
+                    resolveResource(resource, _siteLoader);
+                    Log.info("Loaded site-specific [key=" + resourceKey + "].");
+                } catch (ResourceNotFoundException rnfe) {
+                    // nothing to worry about here
+                }
+            }
+        }
+
+        // try the servlet context loader if we didn't find a
+        // site-specific resource
+        if (resource.getData() == null) {
+            resolveResource(resource, _contextLoader);
+            Log.info("Loaded default [key=" + resourceKey + "].");
+        }
+
+        return resource;
+    }
+
+    protected void resolveResource (Resource resource, ResourceLoader loader)
+        throws ResourceNotFoundException, ParseErrorException, Exception
+    {
+        resource.setResourceLoader(loader);
+        resource.process();
+        resource.setLastModified(loader.getLastModified(resource));
+        resource.setModificationCheckInterval(
+            loader.getModificationCheckInterval());
+        resource.touch();
+    }
+
+    /** A reference to the servlet context through which we'll load
+     * default resources. */
+    protected ServletContext _sctx;
+
+    /** A reference to the site identifier in use by the application. */
+    protected SiteIdentifier _ident;
+
+    /** We use this to load site-specific resources. */
+    protected SiteResourceLoader _siteLoader;
+
+    /** We use this to load default resources. */
+    protected ServletContextResourceLoader _contextLoader;
+}